2009-02-04 21:06:58 +07:00
|
|
|
/*
|
2018-12-10 03:36:33 +07:00
|
|
|
* Integrity Measurement Architecture
|
|
|
|
*
|
2009-02-04 21:06:58 +07:00
|
|
|
* Copyright (C) 2005,2006,2007,2008 IBM Corporation
|
|
|
|
*
|
|
|
|
* Authors:
|
|
|
|
* Reiner Sailer <sailer@watson.ibm.com>
|
|
|
|
* Serge Hallyn <serue@us.ibm.com>
|
|
|
|
* Kylene Hall <kylene@us.ibm.com>
|
|
|
|
* Mimi Zohar <zohar@us.ibm.com>
|
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or
|
|
|
|
* modify it under the terms of the GNU General Public License as
|
|
|
|
* published by the Free Software Foundation, version 2 of the
|
|
|
|
* License.
|
|
|
|
*
|
|
|
|
* File: ima_main.c
|
2009-12-05 03:48:00 +07:00
|
|
|
* implements the IMA hooks: ima_bprm_check, ima_file_mmap,
|
2010-01-27 05:02:40 +07:00
|
|
|
* and ima_file_check.
|
2009-02-04 21:06:58 +07:00
|
|
|
*/
|
2018-03-23 20:41:08 +07:00
|
|
|
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
|
2018-12-15 04:48:07 +07:00
|
|
|
#include <linux/module.h>
|
2009-02-04 21:06:58 +07:00
|
|
|
#include <linux/file.h>
|
|
|
|
#include <linux/binfmts.h>
|
|
|
|
#include <linux/mount.h>
|
|
|
|
#include <linux/mman.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 15:04:11 +07:00
|
|
|
#include <linux/slab.h>
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
#include <linux/xattr.h>
|
2011-08-30 07:19:50 +07:00
|
|
|
#include <linux/ima.h>
|
2017-12-11 18:35:21 +07:00
|
|
|
#include <linux/iversion.h>
|
2018-02-21 23:35:20 +07:00
|
|
|
#include <linux/fs.h>
|
2009-02-04 21:06:58 +07:00
|
|
|
|
|
|
|
#include "ima.h"
|
|
|
|
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
#ifdef CONFIG_IMA_APPRAISE
|
|
|
|
int ima_appraise = IMA_APPRAISE_ENFORCE;
|
|
|
|
#else
|
|
|
|
int ima_appraise;
|
|
|
|
#endif
|
|
|
|
|
2013-04-25 14:43:56 +07:00
|
|
|
int ima_hash_algo = HASH_ALGO_SHA1;
|
2013-06-07 17:16:37 +07:00
|
|
|
static int hash_setup_done;
|
2013-04-25 14:43:56 +07:00
|
|
|
|
2009-02-04 21:06:58 +07:00
|
|
|
static int __init hash_setup(char *str)
|
|
|
|
{
|
2013-06-07 17:16:37 +07:00
|
|
|
struct ima_template_desc *template_desc = ima_template_desc_current();
|
|
|
|
int i;
|
|
|
|
|
|
|
|
if (hash_setup_done)
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
|
|
|
|
if (strncmp(str, "sha1", 4) == 0)
|
|
|
|
ima_hash_algo = HASH_ALGO_SHA1;
|
|
|
|
else if (strncmp(str, "md5", 3) == 0)
|
|
|
|
ima_hash_algo = HASH_ALGO_MD5;
|
2017-10-20 15:01:03 +07:00
|
|
|
else
|
|
|
|
return 1;
|
2013-06-07 17:16:37 +07:00
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
2018-05-21 18:58:02 +07:00
|
|
|
i = match_string(hash_algo_name, HASH_ALGO__LAST, str);
|
|
|
|
if (i < 0)
|
2017-10-20 15:01:03 +07:00
|
|
|
return 1;
|
2018-05-21 18:58:02 +07:00
|
|
|
|
|
|
|
ima_hash_algo = i;
|
2013-06-07 17:16:37 +07:00
|
|
|
out:
|
|
|
|
hash_setup_done = 1;
|
2009-02-04 21:06:58 +07:00
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
__setup("ima_hash=", hash_setup);
|
|
|
|
|
2010-01-21 03:35:41 +07:00
|
|
|
/*
|
2010-11-02 21:13:07 +07:00
|
|
|
* ima_rdwr_violation_check
|
2010-01-21 03:35:41 +07:00
|
|
|
*
|
2010-11-02 21:13:07 +07:00
|
|
|
* Only invalidate the PCR for measured files:
|
2014-03-04 23:04:20 +07:00
|
|
|
* - Opening a file for write when already open for read,
|
2010-01-21 03:35:41 +07:00
|
|
|
* results in a time of measure, time of use (ToMToU) error.
|
|
|
|
* - Opening a file for read when already open for write,
|
2014-03-04 23:04:20 +07:00
|
|
|
* could result in a file measurement error.
|
2010-01-21 03:35:41 +07:00
|
|
|
*
|
|
|
|
*/
|
2014-09-13 00:35:55 +07:00
|
|
|
static void ima_rdwr_violation_check(struct file *file,
|
|
|
|
struct integrity_iint_cache *iint,
|
2014-09-13 00:35:56 +07:00
|
|
|
int must_measure,
|
2014-09-13 00:35:55 +07:00
|
|
|
char **pathbuf,
|
2017-11-30 17:56:02 +07:00
|
|
|
const char **pathname,
|
|
|
|
char *filename)
|
2010-01-21 03:35:41 +07:00
|
|
|
{
|
2013-06-14 05:37:49 +07:00
|
|
|
struct inode *inode = file_inode(file);
|
2010-01-21 03:35:41 +07:00
|
|
|
fmode_t mode = file->f_mode;
|
2010-10-26 01:41:45 +07:00
|
|
|
bool send_tomtou = false, send_writers = false;
|
2010-10-26 01:41:59 +07:00
|
|
|
|
2010-01-21 03:35:41 +07:00
|
|
|
if (mode & FMODE_WRITE) {
|
ima: check inode integrity cache in violation check
When IMA did not support ima-appraisal, existance of the S_IMA flag
clearly indicated that the file was measured. With IMA appraisal S_IMA
flag indicates that file was measured and/or appraised. Because of
this, when measurement is not enabled by the policy, violations are
still reported.
To differentiate between measurement and appraisal policies this
patch checks the inode integrity cache flags. The IMA_MEASURED
flag indicates whether the file was actually measured, while the
IMA_MEASURE flag indicates whether the file should be measured.
Unfortunately, the IMA_MEASURED flag is reset to indicate the file
needs to be re-measured. Thus, this patch checks the IMA_MEASURE
flag.
This patch limits the false positive violation reports, but does
not fix it entirely. The IMA_MEASURE/IMA_MEASURED flags are
indications that, at some point in time, the file opened for read
was in policy, but might not be in policy now (eg. different uid).
Other changes would be needed to further limit false positive
violation reports.
Changelog:
- expanded patch description based on conversation with Roberto (Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-27 15:29:28 +07:00
|
|
|
if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
|
2014-09-13 00:35:55 +07:00
|
|
|
if (!iint)
|
|
|
|
iint = integrity_iint_find(inode);
|
ima: check inode integrity cache in violation check
When IMA did not support ima-appraisal, existance of the S_IMA flag
clearly indicated that the file was measured. With IMA appraisal S_IMA
flag indicates that file was measured and/or appraised. Because of
this, when measurement is not enabled by the policy, violations are
still reported.
To differentiate between measurement and appraisal policies this
patch checks the inode integrity cache flags. The IMA_MEASURED
flag indicates whether the file was actually measured, while the
IMA_MEASURE flag indicates whether the file should be measured.
Unfortunately, the IMA_MEASURED flag is reset to indicate the file
needs to be re-measured. Thus, this patch checks the IMA_MEASURE
flag.
This patch limits the false positive violation reports, but does
not fix it entirely. The IMA_MEASURE/IMA_MEASURED flags are
indications that, at some point in time, the file opened for read
was in policy, but might not be in policy now (eg. different uid).
Other changes would be needed to further limit false positive
violation reports.
Changelog:
- expanded patch description based on conversation with Roberto (Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-27 15:29:28 +07:00
|
|
|
/* IMA_MEASURE is set from reader side */
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
if (iint && test_bit(IMA_MUST_MEASURE,
|
|
|
|
&iint->atomic_flags))
|
ima: check inode integrity cache in violation check
When IMA did not support ima-appraisal, existance of the S_IMA flag
clearly indicated that the file was measured. With IMA appraisal S_IMA
flag indicates that file was measured and/or appraised. Because of
this, when measurement is not enabled by the policy, violations are
still reported.
To differentiate between measurement and appraisal policies this
patch checks the inode integrity cache flags. The IMA_MEASURED
flag indicates whether the file was actually measured, while the
IMA_MEASURE flag indicates whether the file should be measured.
Unfortunately, the IMA_MEASURED flag is reset to indicate the file
needs to be re-measured. Thus, this patch checks the IMA_MEASURE
flag.
This patch limits the false positive violation reports, but does
not fix it entirely. The IMA_MEASURE/IMA_MEASURED flags are
indications that, at some point in time, the file opened for read
was in policy, but might not be in policy now (eg. different uid).
Other changes would be needed to further limit false positive
violation reports.
Changelog:
- expanded patch description based on conversation with Roberto (Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-27 15:29:28 +07:00
|
|
|
send_tomtou = true;
|
|
|
|
}
|
2014-03-27 15:54:11 +07:00
|
|
|
} else {
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
if (must_measure)
|
|
|
|
set_bit(IMA_MUST_MEASURE, &iint->atomic_flags);
|
2018-12-11 15:31:40 +07:00
|
|
|
if (inode_is_open_for_write(inode) && must_measure)
|
2014-03-27 15:54:11 +07:00
|
|
|
send_writers = true;
|
2010-01-21 03:35:41 +07:00
|
|
|
}
|
2010-10-26 01:41:45 +07:00
|
|
|
|
2012-06-20 20:32:55 +07:00
|
|
|
if (!send_tomtou && !send_writers)
|
|
|
|
return;
|
|
|
|
|
2017-01-17 18:45:41 +07:00
|
|
|
*pathname = ima_d_path(&file->f_path, pathbuf, filename);
|
2012-09-04 04:40:17 +07:00
|
|
|
|
2010-10-26 01:41:45 +07:00
|
|
|
if (send_tomtou)
|
2015-04-11 22:12:39 +07:00
|
|
|
ima_add_violation(file, *pathname, iint,
|
|
|
|
"invalid_pcr", "ToMToU");
|
2010-10-26 01:41:45 +07:00
|
|
|
if (send_writers)
|
2015-04-11 22:12:39 +07:00
|
|
|
ima_add_violation(file, *pathname, iint,
|
2012-06-20 20:32:55 +07:00
|
|
|
"invalid_pcr", "open_writers");
|
2010-01-21 03:35:41 +07:00
|
|
|
}
|
|
|
|
|
2011-03-10 02:13:22 +07:00
|
|
|
static void ima_check_last_writer(struct integrity_iint_cache *iint,
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
struct inode *inode, struct file *file)
|
2010-10-26 01:42:05 +07:00
|
|
|
{
|
2011-07-26 15:30:35 +07:00
|
|
|
fmode_t mode = file->f_mode;
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
bool update;
|
2010-10-26 01:42:05 +07:00
|
|
|
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
if (!(mode & FMODE_WRITE))
|
|
|
|
return;
|
|
|
|
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
mutex_lock(&iint->mutex);
|
2014-06-27 22:04:27 +07:00
|
|
|
if (atomic_read(&inode->i_writecount) == 1) {
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
update = test_and_clear_bit(IMA_UPDATE_XATTR,
|
|
|
|
&iint->atomic_flags);
|
2017-12-11 18:35:20 +07:00
|
|
|
if (!IS_I_VERSION(inode) ||
|
2018-02-01 20:15:25 +07:00
|
|
|
!inode_eq_iversion(inode, iint->version) ||
|
2014-06-27 22:04:27 +07:00
|
|
|
(iint->flags & IMA_NEW_FILE)) {
|
|
|
|
iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
|
2016-06-02 01:14:06 +07:00
|
|
|
iint->measured_pcrs = 0;
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
if (update)
|
2014-06-27 22:04:27 +07:00
|
|
|
ima_update_xattr(iint, file);
|
|
|
|
}
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
}
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
mutex_unlock(&iint->mutex);
|
2010-10-26 01:42:05 +07:00
|
|
|
}
|
|
|
|
|
2009-02-04 21:06:58 +07:00
|
|
|
/**
|
|
|
|
* ima_file_free - called on __fput()
|
|
|
|
* @file: pointer to file structure being freed
|
|
|
|
*
|
2010-11-02 21:13:07 +07:00
|
|
|
* Flag files that changed, based on i_version
|
2009-02-04 21:06:58 +07:00
|
|
|
*/
|
|
|
|
void ima_file_free(struct file *file)
|
|
|
|
{
|
2013-01-24 05:07:38 +07:00
|
|
|
struct inode *inode = file_inode(file);
|
2011-03-10 02:13:22 +07:00
|
|
|
struct integrity_iint_cache *iint;
|
2009-02-04 21:06:58 +07:00
|
|
|
|
2014-09-24 15:05:10 +07:00
|
|
|
if (!ima_policy_flag || !S_ISREG(inode->i_mode))
|
2009-02-04 21:06:58 +07:00
|
|
|
return;
|
2010-10-26 01:42:19 +07:00
|
|
|
|
2011-03-10 02:13:22 +07:00
|
|
|
iint = integrity_iint_find(inode);
|
2010-11-02 21:14:22 +07:00
|
|
|
if (!iint)
|
|
|
|
return;
|
2009-02-04 21:06:58 +07:00
|
|
|
|
2010-11-02 21:14:22 +07:00
|
|
|
ima_check_last_writer(iint, inode, file);
|
2009-02-04 21:06:58 +07:00
|
|
|
}
|
|
|
|
|
2018-01-09 04:36:20 +07:00
|
|
|
static int process_measurement(struct file *file, const struct cred *cred,
|
|
|
|
u32 secid, char *buf, loff_t size, int mask,
|
2018-06-09 00:40:10 +07:00
|
|
|
enum ima_hooks func)
|
2009-02-04 21:06:58 +07:00
|
|
|
{
|
2013-01-24 05:07:38 +07:00
|
|
|
struct inode *inode = file_inode(file);
|
2014-09-13 00:35:55 +07:00
|
|
|
struct integrity_iint_cache *iint = NULL;
|
2014-06-13 22:55:48 +07:00
|
|
|
struct ima_template_desc *template_desc;
|
2012-09-04 04:40:17 +07:00
|
|
|
char *pathbuf = NULL;
|
2017-01-17 18:45:41 +07:00
|
|
|
char filename[NAME_MAX];
|
2012-09-04 04:40:17 +07:00
|
|
|
const char *pathname = NULL;
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
int rc = 0, action, must_appraise = 0;
|
2016-06-02 01:14:02 +07:00
|
|
|
int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
|
2014-10-30 17:39:39 +07:00
|
|
|
struct evm_ima_xattr_data *xattr_value = NULL;
|
2013-04-25 14:44:04 +07:00
|
|
|
int xattr_len = 0;
|
2014-09-13 00:35:55 +07:00
|
|
|
bool violation_check;
|
2014-10-30 17:39:39 +07:00
|
|
|
enum hash_algo hash_algo;
|
2009-02-04 21:06:58 +07:00
|
|
|
|
2014-09-13 00:35:54 +07:00
|
|
|
if (!ima_policy_flag || !S_ISREG(inode->i_mode))
|
2009-02-04 21:06:58 +07:00
|
|
|
return 0;
|
2010-10-26 01:42:05 +07:00
|
|
|
|
2012-12-04 05:08:11 +07:00
|
|
|
/* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
|
|
|
|
* bitmask based on the appraise/audit/measurement policy.
|
|
|
|
* Included is the appraise submask.
|
|
|
|
*/
|
2018-01-09 04:36:20 +07:00
|
|
|
action = ima_get_action(inode, cred, secid, mask, func, &pcr);
|
2016-01-15 08:59:14 +07:00
|
|
|
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
|
2014-09-13 00:35:55 +07:00
|
|
|
(ima_policy_flag & IMA_MEASURE));
|
|
|
|
if (!action && !violation_check)
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
must_appraise = action & IMA_APPRAISE;
|
2010-10-26 01:42:05 +07:00
|
|
|
|
2012-12-06 03:14:38 +07:00
|
|
|
/* Is the appraise rule hook specific? */
|
2014-09-03 14:19:57 +07:00
|
|
|
if (action & IMA_FILE_APPRAISE)
|
2016-01-15 08:59:14 +07:00
|
|
|
func = FILE_CHECK;
|
2012-12-06 03:14:38 +07:00
|
|
|
|
2016-01-23 03:40:57 +07:00
|
|
|
inode_lock(inode);
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
|
2014-09-13 00:35:55 +07:00
|
|
|
if (action) {
|
|
|
|
iint = integrity_inode_get(inode);
|
|
|
|
if (!iint)
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
rc = -ENOMEM;
|
2014-09-13 00:35:55 +07:00
|
|
|
}
|
|
|
|
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
if (!rc && violation_check)
|
2014-09-13 00:35:56 +07:00
|
|
|
ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
|
2017-11-30 17:56:02 +07:00
|
|
|
&pathbuf, &pathname, filename);
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
|
|
|
|
inode_unlock(inode);
|
|
|
|
|
|
|
|
if (rc)
|
|
|
|
goto out;
|
|
|
|
if (!action)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
mutex_lock(&iint->mutex);
|
|
|
|
|
|
|
|
if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags))
|
|
|
|
/* reset appraisal flags if ima_inode_post_setattr was called */
|
|
|
|
iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
|
|
|
|
IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
|
|
|
|
IMA_ACTION_FLAGS);
|
|
|
|
|
2018-02-21 23:35:20 +07:00
|
|
|
/*
|
|
|
|
* Re-evaulate the file if either the xattr has changed or the
|
|
|
|
* kernel has no way of detecting file change on the filesystem.
|
|
|
|
* (Limited to privileged mounted filesystems.)
|
|
|
|
*/
|
|
|
|
if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) ||
|
|
|
|
((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) &&
|
2018-02-21 23:36:32 +07:00
|
|
|
!(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) &&
|
|
|
|
!(action & IMA_FAIL_UNVERIFIABLE_SIGS))) {
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
iint->flags &= ~IMA_DONE_MASK;
|
2018-02-21 23:35:20 +07:00
|
|
|
iint->measured_pcrs = 0;
|
|
|
|
}
|
2011-10-19 16:04:40 +07:00
|
|
|
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
/* Determine if already appraised/measured based on bitmask
|
2012-12-04 05:08:11 +07:00
|
|
|
* (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
|
|
|
|
* IMA_AUDIT, IMA_AUDITED)
|
|
|
|
*/
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
iint->flags |= action;
|
2012-06-08 17:58:49 +07:00
|
|
|
action &= IMA_DO_MASK;
|
2016-06-02 01:14:06 +07:00
|
|
|
action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1);
|
|
|
|
|
|
|
|
/* If target pcr is already measured, unset IMA_MEASURE action */
|
|
|
|
if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr)))
|
|
|
|
action ^= IMA_MEASURE;
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
|
ima: support new "hash" and "dont_hash" policy actions
The builtin ima_appraise_tcb policy, which is specified on the boot
command line, can be replaced with a custom policy, normally early in
the boot process. Custom policies can be more restrictive in some ways,
like requiring file signatures, but can be less restrictive in other
ways, like not appraising mutable files. With a less restrictive policy
in place, files in the builtin policy might not be hashed and labeled
with a security.ima hash. On reboot, files which should be labeled in
the ima_appraise_tcb are not labeled, possibly preventing the system
from booting properly.
To resolve this problem, this patch extends the existing IMA policy
actions "measure", "dont_measure", "appraise", "dont_appraise", and
"audit" with "hash" and "dont_hash". The new "hash" action will write
the file hash as security.ima, but without requiring the file to be
appraised as well.
For example, the builtin ima_appraise_tcb policy includes the rule,
"appraise fowner=0". Adding the "hash fowner=0" rule to a custom
policy, will cause the needed file hashes to be calculated and written
as security.ima xattrs.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
2016-09-29 21:04:52 +07:00
|
|
|
/* HASH sets the digital signature and update flags, nothing else */
|
|
|
|
if ((action & IMA_HASH) &&
|
|
|
|
!(test_bit(IMA_DIGSIG, &iint->atomic_flags))) {
|
|
|
|
xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
|
|
|
|
if ((xattr_value && xattr_len > 2) &&
|
|
|
|
(xattr_value->type == EVM_IMA_XATTR_DIGSIG))
|
|
|
|
set_bit(IMA_DIGSIG, &iint->atomic_flags);
|
|
|
|
iint->flags |= IMA_HASHED;
|
|
|
|
action ^= IMA_HASH;
|
|
|
|
set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
|
|
|
|
}
|
|
|
|
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
/* Nothing to do, just return existing appraised status */
|
|
|
|
if (!action) {
|
2012-12-04 05:08:11 +07:00
|
|
|
if (must_appraise)
|
2016-01-15 08:59:14 +07:00
|
|
|
rc = ima_get_cache_status(iint, func);
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
goto out_locked;
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
}
|
2009-02-04 21:06:58 +07:00
|
|
|
|
2014-06-13 22:55:48 +07:00
|
|
|
template_desc = ima_template_desc_current();
|
2014-08-22 13:43:55 +07:00
|
|
|
if ((action & IMA_APPRAISE_SUBMASK) ||
|
|
|
|
strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
|
2014-10-30 17:39:39 +07:00
|
|
|
/* read 'security.ima' */
|
2016-09-16 17:44:20 +07:00
|
|
|
xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
|
2013-04-25 14:44:04 +07:00
|
|
|
|
2014-10-30 17:39:39 +07:00
|
|
|
hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
|
|
|
|
|
2016-01-15 05:57:47 +07:00
|
|
|
rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
|
2017-06-18 10:56:23 +07:00
|
|
|
if (rc != 0 && rc != -EBADF && rc != -EINVAL)
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
goto out_locked;
|
2012-06-20 20:32:55 +07:00
|
|
|
|
2017-01-17 18:45:41 +07:00
|
|
|
if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */
|
|
|
|
pathname = ima_d_path(&file->f_path, &pathbuf, filename);
|
2012-06-20 20:32:55 +07:00
|
|
|
|
ima: integrity appraisal extension
IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party. The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'. The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.
This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement. Protection of the xattr is provided by
EVM, if enabled and configured.
Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.
Changelov v4:
- changed iint cache flags to hex values
Changelog v3:
- change appraisal default for filesystems without xattr support to fail
Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values
Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
(INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
(moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file
Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
iint->mutex, and ima_file_free() and process_measurement(), which take
the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-02-13 22:15:05 +07:00
|
|
|
if (action & IMA_MEASURE)
|
2013-07-23 22:15:00 +07:00
|
|
|
ima_store_measurement(iint, file, pathname,
|
2016-06-02 01:14:03 +07:00
|
|
|
xattr_value, xattr_len, pcr);
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
|
|
|
|
inode_lock(inode);
|
2016-01-15 08:59:14 +07:00
|
|
|
rc = ima_appraise_measurement(func, iint, file, pathname,
|
2018-06-09 00:40:10 +07:00
|
|
|
xattr_value, xattr_len);
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
inode_unlock(inode);
|
|
|
|
}
|
2012-06-15 00:04:36 +07:00
|
|
|
if (action & IMA_AUDIT)
|
2012-09-04 04:40:17 +07:00
|
|
|
ima_audit_measurement(iint, pathname);
|
2014-09-13 00:35:55 +07:00
|
|
|
|
2017-06-18 10:56:23 +07:00
|
|
|
if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
|
|
|
|
rc = 0;
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
out_locked:
|
|
|
|
if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
|
2016-03-01 07:52:05 +07:00
|
|
|
!(iint->flags & IMA_NEW_FILE))
|
2012-09-27 19:06:28 +07:00
|
|
|
rc = -EACCES;
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
mutex_unlock(&iint->mutex);
|
2014-09-13 00:35:55 +07:00
|
|
|
kfree(xattr_value);
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
out:
|
2014-10-02 01:43:10 +07:00
|
|
|
if (pathbuf)
|
|
|
|
__putname(pathbuf);
|
ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.
Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.
More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file. As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.
To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.
Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.
Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
chgrp) and file attributes have changed. On file open, it causes IMA
to clear iint->flags to re-evaluate policy and perform IMA functions
again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
and extended attributes have changed. On file open, it causes IMA to
clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.
Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-06 02:06:34 +07:00
|
|
|
if (must_appraise) {
|
|
|
|
if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE))
|
|
|
|
return -EACCES;
|
|
|
|
if (file->f_mode & FMODE_WRITE)
|
|
|
|
set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
|
|
|
|
}
|
2012-09-27 19:57:10 +07:00
|
|
|
return 0;
|
2009-02-04 21:06:58 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ima_file_mmap - based on policy, collect/store measurement.
|
|
|
|
* @file: pointer to the file to be measured (May be NULL)
|
|
|
|
* @prot: contains the protection that will be applied by the kernel.
|
|
|
|
*
|
|
|
|
* Measure files being mmapped executable based on the ima_must_measure()
|
|
|
|
* policy decision.
|
|
|
|
*
|
2012-09-27 19:57:10 +07:00
|
|
|
* On success return 0. On integrity appraisal error, assuming the file
|
|
|
|
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
|
2009-02-04 21:06:58 +07:00
|
|
|
*/
|
|
|
|
int ima_file_mmap(struct file *file, unsigned long prot)
|
|
|
|
{
|
2018-01-09 04:36:20 +07:00
|
|
|
u32 secid;
|
|
|
|
|
|
|
|
if (file && (prot & PROT_EXEC)) {
|
|
|
|
security_task_getsecid(current, &secid);
|
|
|
|
return process_measurement(file, current_cred(), secid, NULL,
|
2018-06-09 00:40:10 +07:00
|
|
|
0, MAY_EXEC, MMAP_CHECK);
|
2018-01-09 04:36:20 +07:00
|
|
|
}
|
|
|
|
|
2012-09-27 19:57:10 +07:00
|
|
|
return 0;
|
2009-02-04 21:06:58 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* ima_bprm_check - based on policy, collect/store measurement.
|
|
|
|
* @bprm: contains the linux_binprm structure
|
|
|
|
*
|
|
|
|
* The OS protects against an executable file, already open for write,
|
|
|
|
* from being executed in deny_write_access() and an executable file,
|
|
|
|
* already open for execute, from being modified in get_write_access().
|
|
|
|
* So we can be certain that what we verify and measure here is actually
|
|
|
|
* what is being executed.
|
|
|
|
*
|
2012-09-27 19:57:10 +07:00
|
|
|
* On success return 0. On integrity appraisal error, assuming the file
|
|
|
|
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
|
2009-02-04 21:06:58 +07:00
|
|
|
*/
|
|
|
|
int ima_bprm_check(struct linux_binprm *bprm)
|
|
|
|
{
|
2018-01-09 04:36:20 +07:00
|
|
|
int ret;
|
|
|
|
u32 secid;
|
|
|
|
|
|
|
|
security_task_getsecid(current, &secid);
|
|
|
|
ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
|
2018-06-09 00:40:10 +07:00
|
|
|
MAY_EXEC, BPRM_CHECK);
|
2018-01-09 04:36:20 +07:00
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
security_cred_getsecid(bprm->cred, &secid);
|
|
|
|
return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
|
2018-06-09 00:40:10 +07:00
|
|
|
MAY_EXEC, CREDS_CHECK);
|
2009-02-04 21:06:58 +07:00
|
|
|
}
|
|
|
|
|
2010-01-21 03:35:41 +07:00
|
|
|
/**
|
|
|
|
* ima_path_check - based on policy, collect/store measurement.
|
|
|
|
* @file: pointer to the file to be measured
|
2017-01-06 11:38:11 +07:00
|
|
|
* @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND
|
2010-01-21 03:35:41 +07:00
|
|
|
*
|
|
|
|
* Measure files based on the ima_must_measure() policy decision.
|
|
|
|
*
|
2012-09-27 19:57:10 +07:00
|
|
|
* On success return 0. On integrity appraisal error, assuming the file
|
|
|
|
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
|
2010-01-21 03:35:41 +07:00
|
|
|
*/
|
2018-06-09 00:40:10 +07:00
|
|
|
int ima_file_check(struct file *file, int mask)
|
2010-01-21 03:35:41 +07:00
|
|
|
{
|
2018-01-09 04:36:20 +07:00
|
|
|
u32 secid;
|
|
|
|
|
|
|
|
security_task_getsecid(current, &secid);
|
|
|
|
return process_measurement(file, current_cred(), secid, NULL, 0,
|
2017-01-06 11:38:11 +07:00
|
|
|
mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
|
2018-06-09 00:40:10 +07:00
|
|
|
MAY_APPEND), FILE_CHECK);
|
2010-01-21 03:35:41 +07:00
|
|
|
}
|
2010-01-27 05:02:40 +07:00
|
|
|
EXPORT_SYMBOL_GPL(ima_file_check);
|
2010-01-21 03:35:41 +07:00
|
|
|
|
2019-01-23 03:06:49 +07:00
|
|
|
/**
|
|
|
|
* ima_post_create_tmpfile - mark newly created tmpfile as new
|
|
|
|
* @file : newly created tmpfile
|
|
|
|
*
|
|
|
|
* No measuring, appraising or auditing of newly created tmpfiles is needed.
|
|
|
|
* Skip calling process_measurement(), but indicate which newly, created
|
|
|
|
* tmpfiles are in policy.
|
|
|
|
*/
|
|
|
|
void ima_post_create_tmpfile(struct inode *inode)
|
|
|
|
{
|
|
|
|
struct integrity_iint_cache *iint;
|
|
|
|
int must_appraise;
|
|
|
|
|
|
|
|
must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
|
|
|
|
if (!must_appraise)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* Nothing to do if we can't allocate memory */
|
|
|
|
iint = integrity_inode_get(inode);
|
|
|
|
if (!iint)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* needed for writing the security xattrs */
|
|
|
|
set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
|
|
|
|
iint->ima_file_status = INTEGRITY_PASS;
|
|
|
|
}
|
|
|
|
|
2016-03-01 07:52:05 +07:00
|
|
|
/**
|
|
|
|
* ima_post_path_mknod - mark as a new inode
|
|
|
|
* @dentry: newly created dentry
|
|
|
|
*
|
|
|
|
* Mark files created via the mknodat syscall as new, so that the
|
|
|
|
* file data can be written later.
|
|
|
|
*/
|
|
|
|
void ima_post_path_mknod(struct dentry *dentry)
|
|
|
|
{
|
|
|
|
struct integrity_iint_cache *iint;
|
|
|
|
struct inode *inode = dentry->d_inode;
|
|
|
|
int must_appraise;
|
|
|
|
|
|
|
|
must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
|
|
|
|
if (!must_appraise)
|
|
|
|
return;
|
|
|
|
|
2019-01-23 03:06:49 +07:00
|
|
|
/* Nothing to do if we can't allocate memory */
|
2016-03-01 07:52:05 +07:00
|
|
|
iint = integrity_inode_get(inode);
|
2019-01-23 03:06:49 +07:00
|
|
|
if (!iint)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* needed for re-opening empty files */
|
|
|
|
iint->flags |= IMA_NEW_FILE;
|
2016-03-01 07:52:05 +07:00
|
|
|
}
|
|
|
|
|
2016-01-31 10:23:26 +07:00
|
|
|
/**
|
|
|
|
* ima_read_file - pre-measure/appraise hook decision based on policy
|
|
|
|
* @file: pointer to the file to be measured/appraised/audit
|
|
|
|
* @read_id: caller identifier
|
|
|
|
*
|
|
|
|
* Permit reading a file based on policy. The policy rules are written
|
|
|
|
* in terms of the policy identifier. Appraising the integrity of
|
|
|
|
* a file requires a file descriptor.
|
|
|
|
*
|
|
|
|
* For permission return 0, otherwise return -EACCES.
|
|
|
|
*/
|
|
|
|
int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
|
|
|
|
{
|
2018-07-14 01:06:03 +07:00
|
|
|
/*
|
|
|
|
* READING_FIRMWARE_PREALLOC_BUFFER
|
|
|
|
*
|
|
|
|
* Do devices using pre-allocated memory run the risk of the
|
|
|
|
* firmware being accessible to the device prior to the completion
|
|
|
|
* of IMA's signature verification any more than when using two
|
|
|
|
* buffers?
|
|
|
|
*/
|
2016-01-31 10:23:26 +07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2018-09-08 03:22:23 +07:00
|
|
|
static const int read_idmap[READING_MAX_ID] = {
|
ima: support for kexec image and initramfs
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.
Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig
Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes. Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.
Option 1: duplicate kernel_read_file enumeration in ima_hooks
enum kernel_read_file_id {
...
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
enum ima_hooks {
...
KEXEC_KERNEL_CHECK
KEXEC_INITRAMFS_CHECK
Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
FILE_CHECK = READING_MAX_ID,
MMAP_CHECK,
In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.
struct caller_id {
union {
enum ima_hooks func_id;
enum kernel_read_file_id read_id;
};
};
Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.
For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.
Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
2016-01-15 08:59:14 +07:00
|
|
|
[READING_FIRMWARE] = FIRMWARE_CHECK,
|
2018-04-28 01:31:40 +07:00
|
|
|
[READING_FIRMWARE_PREALLOC_BUFFER] = FIRMWARE_CHECK,
|
ima: support for kexec image and initramfs
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.
Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig
Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes. Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.
Option 1: duplicate kernel_read_file enumeration in ima_hooks
enum kernel_read_file_id {
...
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
enum ima_hooks {
...
KEXEC_KERNEL_CHECK
KEXEC_INITRAMFS_CHECK
Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
FILE_CHECK = READING_MAX_ID,
MMAP_CHECK,
In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.
struct caller_id {
union {
enum ima_hooks func_id;
enum kernel_read_file_id read_id;
};
};
Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.
For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.
Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
2016-01-15 08:59:14 +07:00
|
|
|
[READING_MODULE] = MODULE_CHECK,
|
|
|
|
[READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
|
|
|
|
[READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
|
2016-01-15 22:17:12 +07:00
|
|
|
[READING_POLICY] = POLICY_CHECK
|
ima: support for kexec image and initramfs
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.
Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig
Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes. Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.
Option 1: duplicate kernel_read_file enumeration in ima_hooks
enum kernel_read_file_id {
...
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
enum ima_hooks {
...
KEXEC_KERNEL_CHECK
KEXEC_INITRAMFS_CHECK
Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
FILE_CHECK = READING_MAX_ID,
MMAP_CHECK,
In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.
struct caller_id {
union {
enum ima_hooks func_id;
enum kernel_read_file_id read_id;
};
};
Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.
For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.
Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
2016-01-15 08:59:14 +07:00
|
|
|
};
|
|
|
|
|
2016-01-15 05:57:47 +07:00
|
|
|
/**
|
|
|
|
* ima_post_read_file - in memory collect/appraise/audit measurement
|
|
|
|
* @file: pointer to the file to be measured/appraised/audit
|
|
|
|
* @buf: pointer to in memory file contents
|
|
|
|
* @size: size of in memory file contents
|
|
|
|
* @read_id: caller identifier
|
|
|
|
*
|
|
|
|
* Measure/appraise/audit in memory file based on policy. Policy rules
|
|
|
|
* are written in terms of a policy identifier.
|
|
|
|
*
|
|
|
|
* On success return 0. On integrity appraisal error, assuming the file
|
|
|
|
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
|
|
|
|
*/
|
|
|
|
int ima_post_read_file(struct file *file, void *buf, loff_t size,
|
|
|
|
enum kernel_read_file_id read_id)
|
|
|
|
{
|
ima: support for kexec image and initramfs
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.
Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig
Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes. Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.
Option 1: duplicate kernel_read_file enumeration in ima_hooks
enum kernel_read_file_id {
...
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
enum ima_hooks {
...
KEXEC_KERNEL_CHECK
KEXEC_INITRAMFS_CHECK
Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
FILE_CHECK = READING_MAX_ID,
MMAP_CHECK,
In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.
struct caller_id {
union {
enum ima_hooks func_id;
enum kernel_read_file_id read_id;
};
};
Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.
For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.
Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
2016-01-15 08:59:14 +07:00
|
|
|
enum ima_hooks func;
|
2018-01-09 04:36:20 +07:00
|
|
|
u32 secid;
|
2016-01-15 05:57:47 +07:00
|
|
|
|
2015-11-20 00:39:22 +07:00
|
|
|
if (!file && read_id == READING_FIRMWARE) {
|
|
|
|
if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
|
2018-07-14 01:06:00 +07:00
|
|
|
(ima_appraise & IMA_APPRAISE_ENFORCE)) {
|
|
|
|
pr_err("Prevent firmware loading_store.\n");
|
2015-11-20 00:39:22 +07:00
|
|
|
return -EACCES; /* INTEGRITY_UNKNOWN */
|
2018-07-14 01:06:00 +07:00
|
|
|
}
|
2015-11-20 00:39:22 +07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2017-09-10 14:49:45 +07:00
|
|
|
/* permit signed certs */
|
|
|
|
if (!file && read_id == READING_X509_CERTIFICATE)
|
|
|
|
return 0;
|
|
|
|
|
2016-01-15 05:57:47 +07:00
|
|
|
if (!file || !buf || size == 0) { /* should never happen */
|
|
|
|
if (ima_appraise & IMA_APPRAISE_ENFORCE)
|
|
|
|
return -EACCES;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
ima: support for kexec image and initramfs
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.
Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig
Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes. Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.
Option 1: duplicate kernel_read_file enumeration in ima_hooks
enum kernel_read_file_id {
...
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
enum ima_hooks {
...
KEXEC_KERNEL_CHECK
KEXEC_INITRAMFS_CHECK
Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
FILE_CHECK = READING_MAX_ID,
MMAP_CHECK,
In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.
struct caller_id {
union {
enum ima_hooks func_id;
enum kernel_read_file_id read_id;
};
};
Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.
For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.
Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
2016-01-15 08:59:14 +07:00
|
|
|
func = read_idmap[read_id] ?: FILE_CHECK;
|
2018-01-09 04:36:20 +07:00
|
|
|
security_task_getsecid(current, &secid);
|
|
|
|
return process_measurement(file, current_cred(), secid, buf, size,
|
2018-06-09 00:40:10 +07:00
|
|
|
MAY_READ, func);
|
2014-07-22 21:39:48 +07:00
|
|
|
}
|
|
|
|
|
2018-07-14 01:05:58 +07:00
|
|
|
/**
|
|
|
|
* ima_load_data - appraise decision based on policy
|
|
|
|
* @id: kernel load data caller identifier
|
|
|
|
*
|
|
|
|
* Callers of this LSM hook can not measure, appraise, or audit the
|
|
|
|
* data provided by userspace. Enforce policy rules requring a file
|
|
|
|
* signature (eg. kexec'ed kernel image).
|
|
|
|
*
|
|
|
|
* For permission return 0, otherwise return -EACCES.
|
|
|
|
*/
|
|
|
|
int ima_load_data(enum kernel_load_data_id id)
|
|
|
|
{
|
2018-10-10 00:30:34 +07:00
|
|
|
bool ima_enforce, sig_enforce;
|
2018-07-14 01:06:02 +07:00
|
|
|
|
2018-10-10 00:30:34 +07:00
|
|
|
ima_enforce =
|
|
|
|
(ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE;
|
2018-07-14 01:05:58 +07:00
|
|
|
|
|
|
|
switch (id) {
|
|
|
|
case LOADING_KEXEC_IMAGE:
|
2018-10-10 00:30:34 +07:00
|
|
|
if (IS_ENABLED(CONFIG_KEXEC_VERIFY_SIG)
|
|
|
|
&& arch_ima_get_secureboot()) {
|
|
|
|
pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
|
|
|
|
return -EACCES;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) {
|
2018-07-14 01:05:58 +07:00
|
|
|
pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
|
|
|
|
return -EACCES; /* INTEGRITY_UNKNOWN */
|
|
|
|
}
|
2018-07-14 01:06:00 +07:00
|
|
|
break;
|
|
|
|
case LOADING_FIRMWARE:
|
2018-10-10 00:30:34 +07:00
|
|
|
if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE)) {
|
2018-07-14 01:06:00 +07:00
|
|
|
pr_err("Prevent firmware sysfs fallback loading.\n");
|
|
|
|
return -EACCES; /* INTEGRITY_UNKNOWN */
|
|
|
|
}
|
2018-07-14 01:06:02 +07:00
|
|
|
break;
|
|
|
|
case LOADING_MODULE:
|
|
|
|
sig_enforce = is_module_sig_enforced();
|
|
|
|
|
2018-10-10 00:30:34 +07:00
|
|
|
if (ima_enforce && (!sig_enforce
|
|
|
|
&& (ima_appraise & IMA_APPRAISE_MODULES))) {
|
2018-07-14 01:06:02 +07:00
|
|
|
pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
|
|
|
|
return -EACCES; /* INTEGRITY_UNKNOWN */
|
|
|
|
}
|
2018-07-14 01:05:58 +07:00
|
|
|
default:
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-02-04 21:06:58 +07:00
|
|
|
static int __init init_ima(void)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
2016-12-20 07:22:51 +07:00
|
|
|
ima_init_template_list();
|
2013-06-07 17:16:37 +07:00
|
|
|
hash_setup(CONFIG_IMA_DEFAULT_HASH);
|
2009-02-04 21:06:58 +07:00
|
|
|
error = ima_init();
|
2018-03-23 20:41:08 +07:00
|
|
|
|
|
|
|
if (error && strcmp(hash_algo_name[ima_hash_algo],
|
|
|
|
CONFIG_IMA_DEFAULT_HASH) != 0) {
|
|
|
|
pr_info("Allocating %s failed, going to use default hash algorithm %s\n",
|
|
|
|
hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH);
|
|
|
|
hash_setup_done = 0;
|
|
|
|
hash_setup(CONFIG_IMA_DEFAULT_HASH);
|
|
|
|
error = ima_init();
|
|
|
|
}
|
|
|
|
|
2018-05-10 22:15:48 +07:00
|
|
|
if (!error)
|
2014-09-13 00:35:54 +07:00
|
|
|
ima_update_policy_flag();
|
2018-05-10 22:15:48 +07:00
|
|
|
|
2009-02-04 21:06:58 +07:00
|
|
|
return error;
|
|
|
|
}
|
|
|
|
|
|
|
|
late_initcall(init_ima); /* Start IMA after the TPM is available */
|