Commit Graph

422 Commits

Author SHA1 Message Date
Al Viro
fc64005c93 don't bother with ->d_inode->i_sb - it's always equal to ->d_sb
... and neither can ever be NULL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-10 17:11:51 -04:00
Al Viro
81cd8896a6 constify ima_d_path()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28 00:47:52 -04:00
Linus Torvalds
bb7aeae3d6 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris:
 "There are a bunch of fixes to the TPM, IMA, and Keys code, with minor
  fixes scattered across the subsystem.

  IMA now requires signed policy, and that policy is also now measured
  and appraised"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (67 commits)
  X.509: Make algo identifiers text instead of enum
  akcipher: Move the RSA DER encoding check to the crypto layer
  crypto: Add hash param to pkcs1pad
  sign-file: fix build with CMS support disabled
  MAINTAINERS: update tpmdd urls
  MODSIGN: linux/string.h should be #included to get memcpy()
  certs: Fix misaligned data in extra certificate list
  X.509: Handle midnight alternative notation in GeneralizedTime
  X.509: Support leap seconds
  Handle ISO 8601 leap seconds and encodings of midnight in mktime64()
  X.509: Fix leap year handling again
  PKCS#7: fix unitialized boolean 'want'
  firmware: change kernel read fail to dev_dbg()
  KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert
  KEYS: Reserve an extra certificate symbol for inserting without recompiling
  modsign: hide openssl output in silent builds
  tpm_tis: fix build warning with tpm_tis_resume
  ima: require signed IMA policy
  ima: measure and appraise the IMA policy itself
  ima: load policy using path
  ...
2016-03-17 11:33:45 -07:00
James Morris
88a1b564a2 Merge tag 'keys-next-20160303' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next 2016-03-04 11:39:53 +11:00
David Howells
4e8ae72a75 X.509: Make algo identifiers text instead of enum
Make the identifier public key and digest algorithm fields text instead of
enum.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03 21:49:27 +00:00
David Howells
d43de6c780 akcipher: Move the RSA DER encoding check to the crypto layer
Move the RSA EMSA-PKCS1-v1_5 encoding from the asymmetric-key public_key
subtype to the rsa crypto module's pkcs1pad template.  This means that the
public_key subtype no longer has any dependencies on public key type.

To make this work, the following changes have been made:

 (1) The rsa pkcs1pad template is now used for RSA keys.  This strips off the
     padding and returns just the message hash.

 (2) In a previous patch, the pkcs1pad template gained an optional second
     parameter that, if given, specifies the hash used.  We now give this,
     and pkcs1pad checks the encoded message E(M) for the EMSA-PKCS1-v1_5
     encoding and verifies that the correct digest OID is present.

 (3) The crypto driver in crypto/asymmetric_keys/rsa.c is now reduced to
     something that doesn't care about what the encryption actually does
     and and has been merged into public_key.c.

 (4) CONFIG_PUBLIC_KEY_ALGO_RSA is gone.  Module signing must set
     CONFIG_CRYPTO_RSA=y instead.

Thoughts:

 (*) Should the encoding style (eg. raw, EMSA-PKCS1-v1_5) also be passed to
     the padding template?  Should there be multiple padding templates
     registered that share most of the code?

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03 21:49:27 +00:00
Mimi Zohar
95ee08fa37 ima: require signed IMA policy
Require the IMA policy to be signed when additional rules can be added.

v1:
- initialize the policy flag
- include IMA_APPRAISE_POLICY in the policy flag

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>
2016-02-21 09:34:23 -05:00
Mimi Zohar
19f8a84713 ima: measure and appraise the IMA policy itself
Add support for measuring and appraising the IMA policy itself.

Changelog v4:
- use braces on both if/else branches, even if single line on one of the
branches - Dmitry
- Use the id mapping - Dmitry

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>
2016-02-21 09:34:22 -05:00
Dmitry Kasatkin
7429b09281 ima: load policy using path
We currently cannot do appraisal or signature vetting of IMA policies
since we currently can only load IMA policies by writing the contents
of the policy directly in, as follows:

cat policy-file > <securityfs>/ima/policy

If we provide the kernel the path to the IMA policy so it can load
the policy itself it'd be able to later appraise or vet the file
signature if it has one.  This patch adds support to load the IMA
policy with a given path as follows:

echo /etc/ima/ima_policy > /sys/kernel/security/ima/policy

Changelog v4+:
- moved kernel_read_file_from_path() error messages to callers
v3:
- moved kernel_read_file_from_path() to a separate patch
v2:
- after re-ordering the patches, replace calling integrity_kernel_read()
  to read the file with kernel_read_file_from_path() (Mimi)
- Patch description re-written by Luis R. Rodriguez

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-21 09:34:05 -05:00
Mimi Zohar
d9ddf077bb 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>
2016-02-21 09:06:16 -05:00
Mimi Zohar
c6af8efe97 ima: remove firmware and module specific cached status info
Each time a file is read by the kernel, the file should be re-measured and
the file signature re-appraised, based on policy.  As there is no need to
preserve the status information, this patch replaces the firmware and
module specific cache status with a generic one named read_file.

This change simplifies adding support for other files read by the kernel.

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>
2016-02-21 09:06:13 -05:00
Mimi Zohar
a1db742094 module: replace copy_module_from_fd with kernel version
Replace copy_module_from_fd() with kernel_read_file_from_fd().

Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.

The security function security_kernel_module_from_file() was called prior
to reading a kernel module.  Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook.  Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.

This patch removes the security_kernel_module_from_file() hook and security
call.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2016-02-21 09:06:12 -05:00
Mimi Zohar
39eeb4fb97 security: define kernel_read_file hook
The kernel_read_file security hook is called prior to reading the file
into memory.

Changelog v4+:
- export security_kernel_read_file()

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2016-02-21 09:06:09 -05:00
Mimi Zohar
e40ba6d56b firmware: replace call to fw_read_file_contents() with kernel version
Replace the fw_read_file_contents with kernel_file_read_from_path().

Although none of the upstreamed LSMs define a kernel_fw_from_file hook,
IMA is called by the security function to prevent unsigned firmware from
being loaded and to measure/appraise signed firmware, based on policy.

Instead of reading the firmware twice, once for measuring/appraising the
firmware and again for reading the firmware contents into memory, the
kernel_post_read_file() security hook calculates the file hash based on
the in memory file buffer.  The firmware is read once.

This patch removes the LSM kernel_fw_from_file() hook and security call.

Changelog v4+:
- revert dropped buf->size assignment - reported by Sergey Senozhatsky
v3:
- remove kernel_fw_from_file hook
- use kernel_file_read_from_path() - requested by Luis
v2:
- reordered and squashed firmware patches
- fix MAX firmware size (Kees Cook)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
2016-02-21 09:03:44 -05:00
Mimi Zohar
cf22221786 ima: define a new hook to measure and appraise a file already in memory
This patch defines a new IMA hook ima_post_read_file() for measuring
and appraising files read by the kernel. The caller loads the file into
memory before calling this function, which calculates the hash followed by
the normal IMA policy based processing.

Changelog v5:
- fail ima_post_read_file() if either file or buf is NULL
v3:
- rename ima_hash_and_process_file() to ima_post_read_file()

v1:
- split patch

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-20 22:35:08 -05:00
Mimi Zohar
98304bcf71 ima: calculate the hash of a buffer using aynchronous hash(ahash)
Setting up ahash has some overhead.  Only use ahash to calculate the
hash of a buffer, if the buffer is larger than ima_ahash_minsize.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-18 17:14:44 -05:00
Dmitry Kasatkin
11d7646df8 ima: provide buffer hash calculation function
This patch provides convenient buffer hash calculation function.

Changelog v3:
- fix while hash calculation - Dmitry
v1:
- rewrite to support loff_t sized buffers - Mimi
  (based on Fenguang Wu's testing)

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-18 17:14:28 -05:00
Mimi Zohar
4ad87a3d74 ima: use "ima_hooks" enum as function argument
Cleanup the function arguments by using "ima_hooks" enumerator as needed.

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>
2016-02-18 17:13:58 -05:00
Mimi Zohar
b5269ab3e2 ima: refactor ima_policy_show() to display "ima_hooks" rules
Define and call a function to display the "ima_hooks" rules.

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>
2016-02-18 17:13:56 -05:00
Dmitry Kasatkin
1525b06d99 ima: separate 'security.ima' reading functionality from collect
Instead of passing pointers to pointers to ima_collect_measurent() to
read and return the 'security.ima' xattr value, this patch moves the
functionality to the calling process_measurement() to directly read
the xattr and pass only the hash algo to the ima_collect_measurement().

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-18 17:13:32 -05:00
Tadeusz Struk
eb5798f2e2 integrity: convert digsig to akcipher api
Convert asymmetric_verify to akcipher api.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-02-18 14:52:32 +00:00
Ryan Ware
613317bd21 EVM: Use crypto_memneq() for digest comparisons
This patch fixes vulnerability CVE-2016-2085.  The problem exists
because the vm_verify_hmac() function includes a use of memcmp().
Unfortunately, this allows timing side channel attacks; specifically
a MAC forgery complexity drop from 2^128 to 2^12.  This patch changes
the memcmp() to the cryptographically safe crypto_memneq().

Reported-by: Xiaofei Rex Guo <xiaofei.rex.guo@intel.com>
Signed-off-by: Ryan Ware <ware@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-02-12 18:36:47 +11:00
David Howells
50d35015ff KEYS: CONFIG_KEYS_DEBUG_PROC_KEYS is no longer an option
CONFIG_KEYS_DEBUG_PROC_KEYS is no longer an option as /proc/keys is now
mandatory if the keyrings facility is enabled (it's used by libkeyutils in
userspace).

The defconfig references were removed with:

	perl -p -i -e 's/CONFIG_KEYS_DEBUG_PROC_KEYS=y\n//' \
	    `git grep -l CONFIG_KEYS_DEBUG_PROC_KEYS=y`

and the integrity Kconfig fixed by hand.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Andreas Ziegler <andreas.ziegler@fau.de>
cc: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-10 10:13:27 +00:00
Colin Ian King
c75d8e96f3 IMA: fix non-ANSI declaration of ima_check_policy()
ima_check_policy() has no parameters, so use the normal void
parameter convention to make it match the prototype in the header file
security/integrity/ima/ima.h

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-08 18:17:38 -05:00
Al Viro
5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Linus Torvalds
5807fcaa9b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:

 - EVM gains support for loading an x509 cert from the kernel
   (EVM_LOAD_X509), into the EVM trusted kernel keyring.

 - Smack implements 'file receive' process-based permission checking for
   sockets, rather than just depending on inode checks.

 - Misc enhancments for TPM & TPM2.

 - Cleanups and bugfixes for SELinux, Keys, and IMA.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits)
  selinux: Inode label revalidation performance fix
  KEYS: refcount bug fix
  ima: ima_write_policy() limit locking
  IMA: policy can be updated zero times
  selinux: rate-limit netlink message warnings in selinux_nlmsg_perm()
  selinux: export validatetrans decisions
  gfs2: Invalid security labels of inodes when they go invalid
  selinux: Revalidate invalid inode security labels
  security: Add hook to invalidate inode security labels
  selinux: Add accessor functions for inode->i_security
  security: Make inode argument of inode_getsecid non-const
  security: Make inode argument of inode_getsecurity non-const
  selinux: Remove unused variable in selinux_inode_init_security
  keys, trusted: seal with a TPM2 authorization policy
  keys, trusted: select hash algorithm for TPM2 chips
  keys, trusted: fix: *do not* allow duplicate key options
  tpm_ibmvtpm: properly handle interrupted packet receptions
  tpm_tis: Tighten IRQ auto-probing
  tpm_tis: Refactor the interrupt setup
  tpm_tis: Get rid of the duplicate IRQ probing code
  ...
2016-01-17 19:13:15 -08:00
Al Viro
cc4e719e83 fix the leak in integrity_read_file()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-04 10:28:19 -05:00
Petko Manolov
6427e6c71c ima: ima_write_policy() limit locking
There is no need to hold the ima_write_mutex for so long.  We only need it
around ima_parse_add_rule().

Changelog:
- The return path now takes into account failed kmalloc() call.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Petko Manolov <petkan@mip-labs.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-01-03 13:22:38 -05:00
Sasha Levin
0112721df4 IMA: policy can be updated zero times
Commit "IMA: policy can now be updated multiple times" assumed that the
policy would be updated at least once.

If there are zero updates, the temporary list head object will get added
to the policy list, and later dereferenced as an IMA policy object, which
means that invalid memory will be accessed.

Changelog:
- Move list_empty() test to ima_release_policy(), before audit msg - Mimi

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-24 18:56:45 -05:00
Paul Gortmaker
92cc916638 security/integrity: make ima/ima_mok.c explicitly non-modular
The Kconfig currently controlling compilation of this code is:

ima/Kconfig:config IMA_MOK_KEYRING
ima/Kconfig: bool "Create IMA machine owner keys (MOK) and blacklist keyrings"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple of traces of modularity so that when reading the
driver there is no doubt it really is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-ima-devel@lists.sourceforge.net
Cc: linux-ima-user@lists.sourceforge.net
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 10:01:43 -05:00
Mimi Zohar
6ad6afa146 ima: update appraise flags after policy update completes
While creating a temporary list of new rules, the ima_appraise flag is
updated, but not reverted on failure to append the new rules to the
existing policy.  This patch defines temp_ima_appraise flag.  Only when
the new rules are appended to the policy is the flag updated.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
2015-12-15 10:01:43 -05:00
Mimi Zohar
501f1bde66 IMA: prevent keys on the .ima_blacklist from being removed
Set the KEY_FLAGS_KEEP on the .ima_blacklist to prevent userspace
from removing keys from the keyring.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 10:01:43 -05:00
Petko Manolov
80eae209d6 IMA: allow reading back the current IMA policy
It is often useful to be able to read back the IMA policy.  It is
even more important after introducing CONFIG_IMA_WRITE_POLICY.
This option allows the root user to see the current policy rules.

Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Signed-off-by: Petko Manolov <petkan@mip-labs.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 10:01:43 -05:00
Petko Manolov
41c89b64d7 IMA: create machine owner and blacklist keyrings
This option creates IMA MOK and blacklist keyrings.  IMA MOK is an
intermediate keyring that sits between .system and .ima keyrings,
effectively forming a simple CA hierarchy.  To successfully import a key
into .ima_mok it must be signed by a key which CA is in .system keyring.
On turn any key that needs to go in .ima keyring must be signed by CA in
either .system or .ima_mok keyrings. IMA MOK is empty at kernel boot.

IMA blacklist keyring contains all revoked IMA keys.  It is consulted
before any other keyring.  If the search is successful the requested
operation is rejected and error is returned to the caller.

Signed-off-by: Petko Manolov <petkan@mip-labs.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 10:01:43 -05:00
Petko Manolov
38d859f991 IMA: policy can now be updated multiple times
The new rules get appended to the original policy, forming a queue.
The new rules are first added to a temporary list, which on error
get released without disturbing the normal IMA operations.  On
success both lists (the current policy and the new rules) are spliced.

IMA policy reads are many orders of magnitude more numerous compared to
writes, the match code is RCU protected.  The updater side also does
list splice in RCU manner.

Signed-off-by: Petko Manolov <petkan@mip-labs.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 10:01:43 -05:00
Arnd Bergmann
05d3884b1e evm: EVM_LOAD_X509 depends on EVM
The newly added EVM_LOAD_X509 code can be configured even if
CONFIG_EVM is disabled, but that causes a link error:

security/built-in.o: In function `integrity_load_keys':
digsig_asymmetric.c:(.init.text+0x400): undefined reference to `evm_load_x509'

This adds a Kconfig dependency to ensure it is only enabled when
CONFIG_EVM is set as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 2ce523eb89 ("evm: load x509 certificate from the kernel")
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 09:57:21 -05:00
Dmitry Kasatkin
523b74b16b evm: reset EVM status when file attributes change
The EVM verification status is cached in iint->evm_status and if it
was successful, never re-verified again when IMA passes the 'iint' to
evm_verifyxattr().

When file attributes or extended attributes change, we may wish to
re-verify EVM integrity as well.  For example, after setting a digital
signature we may need to re-verify the signature and update the
iint->flags that there is an EVM signature.

This patch enables that by resetting evm_status to INTEGRITY_UKNOWN
state.

Changes in v2:
* Flag setting moved to EVM layer

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 09:56:57 -05:00
Dmitry Kasatkin
7626676320 evm: provide a function to set the EVM key from the kernel
A crypto HW kernel module can possibly initialize the EVM key from the
kernel __init code to enable EVM before calling the 'init' process.
This patch provides a function evm_set_key() to set the EVM key
directly without using the KEY subsystem.

Changes in v4:
* kernel-doc style for evm_set_key

Changes in v3:
* error reporting moved to evm_set_key
* EVM_INIT_HMAC moved to evm_set_key
* added bitop to prevent key setting race

Changes in v2:
* use size_t for key size instead of signed int
* provide EVM_MAX_KEY_SIZE macro in <linux/evm.h>
* provide EVM_MIN_KEY_SIZE macro in <linux/evm.h>

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 08:53:36 -05:00
Dmitry Kasatkin
26ddabfe96 evm: enable EVM when X509 certificate is loaded
In order to enable EVM before starting the 'init' process,
evm_initialized needs to be non-zero.  Previously non-zero indicated
that the HMAC key was loaded.  When EVM loads the X509 before calling
'init', with this patch it is now possible to enable EVM to start
signature based verification.

This patch defines bits to enable EVM if a key of any type is loaded.

Changes in v3:
* print error message if key is not set

Changes in v2:
* EVM_STATE_KEY_SET replaced by EVM_INIT_HMAC
* EVM_STATE_X509_SET replaced by EVM_INIT_X509

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 08:50:48 -05:00
Dmitry Kasatkin
2ce523eb89 evm: load an x509 certificate from the kernel
This patch defines a configuration option and the evm_load_x509() hook
to load an X509 certificate onto the EVM trusted kernel keyring.

Changes in v4:
* Patch description updated

Changes in v3:
* Removed EVM_X509_PATH definition. CONFIG_EVM_X509_PATH is used
  directly.

Changes in v2:
* default key patch changed to /etc/keys

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 08:31:19 -05:00
Dmitry Kasatkin
f4dc37785e integrity: define '.evm' as a builtin 'trusted' keyring
Require all keys added to the EVM keyring be signed by an
existing trusted key on the system trusted keyring.

This patch also switches IMA to use integrity_init_keyring().

Changes in v3:
* Added 'init_keyring' config based variable to skip initializing
  keyring instead of using  __integrity_init_keyring() wrapper.
* Added dependency back to CONFIG_IMA_TRUSTED_KEYRING

Changes in v2:
* Replace CONFIG_EVM_TRUSTED_KEYRING with IMA and EVM common
  CONFIG_INTEGRITY_TRUSTED_KEYRING configuration option
* Deprecate CONFIG_IMA_TRUSTED_KEYRING but keep it for config
  file compatibility. (Mimi Zohar)

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-11-23 14:30:02 -05:00
Mel Gorman
71baba4b92 mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep.  Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep.  The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake.  As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags.  This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
David Howells
146aa8b145 KEYS: Merge the type-specific data with the payload data
Merge the type-specific data with the payload data into one four-word chunk
as it seems pointless to keep them separate.

Use user_key_payload() for accessing the payloads of overloaded
user-defined keys.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
cc: ecryptfs@vger.kernel.org
cc: linux-ext4@vger.kernel.org
cc: linux-f2fs-devel@lists.sourceforge.net
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-ima-devel@lists.sourceforge.net
2015-10-21 15:18:36 +01:00
Dmitry Kasatkin
72e1eed8ab integrity: prevent loading untrusted certificates on the IMA trusted keyring
If IMA_LOAD_X509 is enabled, either directly or indirectly via
IMA_APPRAISE_SIGNED_INIT, certificates are loaded onto the IMA
trusted keyring by the kernel via key_create_or_update(). When
the KEY_ALLOC_TRUSTED flag is provided, certificates are loaded
without first verifying the certificate is properly signed by a
trusted key on the system keyring.  This patch removes the
KEY_ALLOC_TRUSTED flag.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc:  <stable@vger.kernel.org> # 3.19+
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-10-09 15:31:18 -04:00
Linus Torvalds
02201e3f1b Minor merge needed, due to function move.
Main excitement here is Peter Zijlstra's lockless rbtree optimization to
 speed module address lookup.  He found some abusers of the module lock
 doing that too.
 
 A little bit of parameter work here too; including Dan Streetman's breaking
 up the big param mutex so writing a parameter can load another module (yeah,
 really).  Unfortunately that broke the usual suspects, !CONFIG_MODULES and
 !CONFIG_SYSFS, so those fixes were appended too.
 
 Cheers,
 Rusty.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "Main excitement here is Peter Zijlstra's lockless rbtree optimization
  to speed module address lookup.  He found some abusers of the module
  lock doing that too.

  A little bit of parameter work here too; including Dan Streetman's
  breaking up the big param mutex so writing a parameter can load
  another module (yeah, really).  Unfortunately that broke the usual
  suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were
  appended too"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits)
  modules: only use mod->param_lock if CONFIG_MODULES
  param: fix module param locks when !CONFIG_SYSFS.
  rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()
  module: add per-module param_lock
  module: make perm const
  params: suppress unused variable error, warn once just in case code changes.
  modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.
  kernel/module.c: avoid ifdefs for sig_enforce declaration
  kernel/workqueue.c: remove ifdefs over wq_power_efficient
  kernel/params.c: export param_ops_bool_enable_only
  kernel/params.c: generalize bool_enable_only
  kernel/module.c: use generic module param operaters for sig_enforce
  kernel/params: constify struct kernel_param_ops uses
  sysfs: tightened sysfs permission checks
  module: Rework module_addr_{min,max}
  module: Use __module_address() for module_address_lookup()
  module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING
  module: Optimize __module_address() using a latched RB-tree
  rbtree: Implement generic latch_tree
  seqlock: Introduce raw_read_seqcount_latch()
  ...
2015-07-01 10:49:25 -07:00
Mimi Zohar
24fd03c876 ima: update builtin policies
This patch defines a builtin measurement policy "tcb", similar to the
existing "ima_tcb", but with additional rules to also measure files
based on the effective uid and to measure files opened with the "read"
mode bit set (eg. read, read-write).

Changing the builtin "ima_tcb" policy could potentially break existing
users.  Instead of defining a new separate boot command line option each
time the builtin measurement policy is modified, this patch defines a
single generic boot command line option "ima_policy=" to specify the
builtin policy and deprecates the use of the builtin ima_tcb policy.

[The "ima_policy=" boot command line option is based on Roberto Sassu's
"ima: added new policy type exec" patch.]

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dr. Greg Wettstein <gw@idfusion.org>
Cc: stable@vger.kernel.org
2015-06-16 08:18:45 -04:00
Mimi Zohar
4351c294b8 ima: extend "mask" policy matching support
The current "mask" policy option matches files opened as MAY_READ,
MAY_WRITE, MAY_APPEND or MAY_EXEC.  This patch extends the "mask"
option to match files opened containing one of these modes.  For
example, "mask=^MAY_READ" would match files opened read-write.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dr. Greg Wettstein <gw@idfusion.org>
Cc: stable@vger.kernel.org
2015-06-16 08:18:44 -04:00
Mimi Zohar
139069eff7 ima: add support for new "euid" policy condition
The new "euid" policy condition measures files with the specified
effective uid (euid).  In addition, for CAP_SETUID files it measures
files with the specified uid or suid.

Changelog:
- fixed checkpatch.pl warnings
- fixed avc denied {setuid} messages - based on Roberto's feedback

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dr. Greg Wettstein <gw@idfusion.org>
Cc: stable@vger.kernel.org
2015-06-16 08:18:43 -04:00
Mimi Zohar
45b26133b9 ima: fix ima_show_template_data_ascii()
This patch fixes a bug introduced in "4d7aeee ima: define new template
ima-ng and template fields d-ng and n-ng".

Changelog:
- change int to uint32 (Roberto Sassu's suggestion)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Roberto Sassu <rsassu@suse.de>
Cc: stable@vger.kernel.org # 3.13
2015-06-16 08:18:21 -04:00
Luis R. Rodriguez
9c27847dda kernel/params: constify struct kernel_param_ops uses
Most code already uses consts for the struct kernel_param_ops,
sweep the kernel for the last offending stragglers. Other than
include/linux/moduleparam.h and kernel/params.c all other changes
were generated with the following Coccinelle SmPL patch. Merge
conflicts between trees can be handled with Coccinelle.

In the future git could get Coccinelle merge support to deal with
patch --> fail --> grammar --> Coccinelle --> new patch conflicts
automatically for us on patches where the grammar is available and
the patch is of high confidence. Consider this a feature request.

Test compiled on x86_64 against:

	* allnoconfig
	* allmodconfig
	* allyesconfig

@ const_found @
identifier ops;
@@

const struct kernel_param_ops ops = {
};

@ const_not_found depends on !const_found @
identifier ops;
@@

-struct kernel_param_ops ops = {
+const struct kernel_param_ops ops = {
};

Generated-by: Coccinelle SmPL
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:10 +09:30
Roberto Sassu
8d94eb9b5c ima: pass iint to ima_add_violation()
This patch adds the iint associated to the current inode as a new
parameter of ima_add_violation(). The passed iint is always not NULL
if a violation is detected. This modification will be used to determine
the inode for which there is a violation.

Since the 'd' and 'd-ng' template field init() functions were detecting
a violation from the value of the iint pointer, they now check the new
field 'violation', added to the 'ima_event_data' structure.

Changelog:
 - v1:
   - modified an old comment (Roberto Sassu)

Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:59:29 -04:00
Roberto Sassu
23b5741932 ima: wrap event related data to the new ima_event_data structure
All event related data has been wrapped into the new 'ima_event_data'
structure. The main benefit of this patch is that a new information
can be made available to template fields initialization functions
by simply adding a new field to the new structure instead of modifying
the definition of those functions.

Changelog:
 - v2:
   - f_dentry replaced with f_path.dentry (Roberto Sassu)
   - removed declaration of temporary variables in template field functions
     when possible (suggested by Dmitry Kasatkin)

Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:59:28 -04:00
Dmitry Kasatkin
9d03a721a3 integrity: add validity checks for 'path' parameter
This patch adds validity checks for 'path' parameter and
makes it const.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:59:28 -04:00
Dmitry Kasatkin
7c51bb00c4 evm: fix potential race when removing xattrs
EVM needs to be atomically updated when removing xattrs.
Otherwise concurrent EVM verification may fail in between.
This patch fixes by moving i_mutex unlocking after calling
EVM hook. fsnotify_xattr() is also now called while locked
the same way as it is done in __vfs_setxattr_noperm.

Changelog:
- remove unused 'inode' variable.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:28:47 -04:00
Mimi Zohar
5101a1850b evm: labeling pseudo filesystems exception
To prevent offline stripping of existing file xattrs and relabeling of
them at runtime, EVM allows only newly created files to be labeled.  As
pseudo filesystems are not persistent, stripping of xattrs is not a
concern.

Some LSMs defer file labeling on pseudo filesystems.  This patch
permits the labeling of existing files on pseudo files systems.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:28:47 -04:00
Dmitry Kasatkin
a18d0cbfab ima: remove definition of IMA_X509_PATH
CONFIG_IMA_X509_PATH is always defined.  This patch removes the
IMA_X509_PATH definition and uses CONFIG_IMA_X509_PATH.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:28:47 -04:00
Dmitry Kasatkin
c68ed80c97 ima: limit file hash setting by user to fix and log modes
File hashes are automatically set and updated and should not be
manually set. This patch limits file hash setting to fix and log
modes.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:28:46 -04:00
Mimi Zohar
cd025f7f94 ima: do not measure or appraise the NSFS filesystem
Include don't appraise or measure rules for the NSFS filesystem
in the builtin ima_tcb and ima_appraise_tcb policies.

Changelog:
- Update documentation

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.19
2015-05-21 13:28:41 -04:00
Roberto Sassu
6438de9f3f ima: skip measurement of cgroupfs files and update documentation
This patch adds a rule in the default measurement policy to skip inodes
in the cgroupfs filesystem. Measurements for this filesystem can be
avoided, as all the digests collected have the same value of the digest of
an empty file.

Furthermore, this patch updates the documentation of IMA policies in
Documentation/ABI/testing/ima_policy to make it consistent with
the policies set in security/integrity/ima/ima_policy.c.

Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:27:19 -04:00
Dan Carpenter
5577857f8e ima: cleanup ima_init_policy() a little
It's a bit easier to read this if we split it up into two for loops.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-13 06:07:19 -04:00
David Howells
c6f493d631 VFS: security/: d_backing_inode() annotations
most of the ->d_inode uses there refer to the same inode IO would
go to, i.e. d_backing_inode()

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:56 -04:00
Linus Torvalds
b11a278397 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kconfig updates from Michal Marek:
 "Yann E Morin was supposed to take over kconfig maintainership, but
  this hasn't happened.  So I'm sending a few kconfig patches that I
  collected:

   - Fix for missing va_end in kconfig
   - merge_config.sh displays used if given too few arguments
   - s/boolean/bool/ in Kconfig files for consistency, with the plan to
     only support bool in the future"

* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kconfig: use va_end to match corresponding va_start
  merge_config.sh: Display usage if given too few arguments
  kconfig: use bool instead of boolean for type definition attributes
2015-02-19 10:36:45 -08:00
David Howells
11cd64a234 ima: /proc/keys is now mandatory
/proc/keys is now mandatory and its config option no longer exists, so it
doesn't need selecting.

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2015-02-02 13:19:48 +11:00
Christoph Jaeger
6341e62b21 kconfig: use bool instead of boolean for type definition attributes
Support for keyword 'boolean' will be dropped later on.

No functional change.

Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com
Signed-off-by: Christoph Jaeger <cj@linux.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-07 13:08:04 +01:00
James Morris
d0bffab043 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into for-linus 2014-12-16 12:49:10 +11:00
Linus Torvalds
67e2c38838 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris:
 "In terms of changes, there's general maintenance to the Smack,
  SELinux, and integrity code.

  The IMA code adds a new kconfig option, IMA_APPRAISE_SIGNED_INIT,
  which allows IMA appraisal to require signatures.  Support for reading
  keys from rootfs before init is call is also added"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
  selinux: Remove security_ops extern
  security: smack: fix out-of-bounds access in smk_parse_smack()
  VFS: refactor vfs_read()
  ima: require signature based appraisal
  integrity: provide a hook to load keys when rootfs is ready
  ima: load x509 certificate from the kernel
  integrity: provide a function to load x509 certificate from the kernel
  integrity: define a new function integrity_read_file()
  Security: smack: replace kzalloc with kmem_cache for inode_smack
  Smack: Lock mode for the floor and hat labels
  ima: added support for new kernel cmdline parameter ima_template_fmt
  ima: allocate field pointers array on demand in template_desc_init_fields()
  ima: don't allocate a copy of template_fmt in template_desc_init_fields()
  ima: display template format in meas. list if template name length is zero
  ima: added error messages to template-related functions
  ima: use atomic bit operations to protect policy update interface
  ima: ignore empty and with whitespaces policy lines
  ima: no need to allocate entry for comment
  ima: report policy load status
  ima: use path names cache
  ...
2014-12-14 20:36:37 -08:00
Al Viro
ba00410b81 Merge branch 'iov_iter' into for-next 2014-12-08 20:39:29 -05:00
Michael Ellerman
63a0eb7891 ima: Fix build failure on powerpc when TCG_IBMVTPM dependencies are not met
On powerpc we can end up with IMA=y and PPC_PSERIES=n which leads to:

 warning: (IMA) selects TCG_IBMVTPM which has unmet direct dependencies (TCG_TPM && PPC_PSERIES)
  tpm_ibmvtpm.c:(.text+0x14f3e8): undefined reference to `.plpar_hcall_norets'

I'm not sure why IMA needs to select those user-visible symbols, but if
it must then the simplest fix is to just express the proper dependencies
on the select.

Tested-by: Hon Ching (Vicky) Lo <lo1@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-12-06 21:50:37 -05:00
Al Viro
b583043e99 kill f_dentry uses
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19 13:01:25 -05:00
Dmitry Kasatkin
6fb5032ebb VFS: refactor vfs_read()
integrity_kernel_read() duplicates the file read operations code
in vfs_read(). This patch refactors vfs_read() code creating a
helper function __vfs_read(). It is used by both vfs_read() and
integrity_kernel_read().

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:14:22 -05:00
Dmitry Kasatkin
c57782c13e ima: require signature based appraisal
This patch provides CONFIG_IMA_APPRAISE_SIGNED_INIT kernel configuration
option to force IMA appraisal using signatures. This is useful, when EVM
key is not initialized yet and we want securely initialize integrity or
any other functionality.

It forces embedded policy to require signature. Signed initialization
script can initialize EVM key, update the IMA policy and change further
requirement of everything to be signed.

Changes in v3:
* kernel parameter fixed to configuration option in the patch description

Changes in v2:
* policy change of this patch separated from the key loading patch

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:12:01 -05:00
Dmitry Kasatkin
c9cd2ce2bc integrity: provide a hook to load keys when rootfs is ready
Keys can only be loaded once the rootfs is mounted. Initcalls
are not suitable for that. This patch defines a special hook
to load the x509 public keys onto the IMA keyring, before
attempting to access any file. The keys are required for
verifying the file's signature. The hook is called after the
root filesystem is mounted and before the kernel calls 'init'.

Changes in v3:
* added more explanation to the patch description (Mimi)

Changes in v2:
* Hook renamed as 'integrity_load_keys()' to handle both IMA and EVM
  keys by integrity subsystem.
* Hook patch moved after defining loading functions

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:12:01 -05:00
Dmitry Kasatkin
fd5f4e9054 ima: load x509 certificate from the kernel
Define configuration option to load X509 certificate into the
IMA trusted kernel keyring. It implements ima_load_x509() hook
to load X509 certificate into the .ima trusted kernel keyring
from the root filesystem.

Changes in v3:
* use ima_policy_flag in ima_get_action()
  ima_load_x509 temporarily clears ima_policy_flag to disable
  appraisal to load key. Use it to skip appraisal rules.
* Key directory path changed to /etc/keys (Mimi)
* Expand IMA_LOAD_X509 Kconfig help

Changes in v2:
* added '__init'
* use ima_policy_flag to disable appraisal to load keys

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:12:00 -05:00
Dmitry Kasatkin
65d543b233 integrity: provide a function to load x509 certificate from the kernel
Provide the function to load x509 certificates from the kernel into the
integrity kernel keyring.

Changes in v2:
* configuration option removed
* function declared as '__init'

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:11:59 -05:00
Dmitry Kasatkin
e3c4abbfa9 integrity: define a new function integrity_read_file()
This patch defines a new function called integrity_read_file()
to read file from the kernel into a buffer. Subsequent patches
will read a file containing the public keys and load them onto
the IMA keyring.

This patch moves and renames ima_kernel_read(), the non-security
checking version of kernel_read(), to integrity_kernel_read().

Changes in v3:
* Patch descriptions improved (Mimi)
* Add missing cast (kbuild test robot)

Changes in v2:
* configuration option removed
* function declared as '__init'

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:09:18 -05:00
James Morris
6c880ad51b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into for-linus 2014-10-29 15:03:54 +11:00
Dmitry Kasatkin
3b1deef6b1 evm: check xattr value length and type in evm_inode_setxattr()
evm_inode_setxattr() can be called with no value. The function does not
check the length so that following command can be used to produce the
kernel oops: setfattr -n security.evm FOO. This patch fixes it.

Changes in v3:
* there is no reason to return different error codes for EVM_XATTR_HMAC
  and non EVM_XATTR_HMAC. Remove unnecessary test then.

Changes in v2:
* testing for validity of xattr type

[ 1106.396921] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 1106.398192] IP: [<ffffffff812af7b8>] evm_inode_setxattr+0x2a/0x48
[ 1106.399244] PGD 29048067 PUD 290d7067 PMD 0
[ 1106.399953] Oops: 0000 [#1] SMP
[ 1106.400020] Modules linked in: bridge stp llc evdev serio_raw i2c_piix4 button fuse
[ 1106.400020] CPU: 0 PID: 3635 Comm: setxattr Not tainted 3.16.0-kds+ #2936
[ 1106.400020] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1106.400020] task: ffff8800291a0000 ti: ffff88002917c000 task.ti: ffff88002917c000
[ 1106.400020] RIP: 0010:[<ffffffff812af7b8>]  [<ffffffff812af7b8>] evm_inode_setxattr+0x2a/0x48
[ 1106.400020] RSP: 0018:ffff88002917fd50  EFLAGS: 00010246
[ 1106.400020] RAX: 0000000000000000 RBX: ffff88002917fdf8 RCX: 0000000000000000
[ 1106.400020] RDX: 0000000000000000 RSI: ffffffff818136d3 RDI: ffff88002917fdf8
[ 1106.400020] RBP: ffff88002917fd68 R08: 0000000000000000 R09: 00000000003ec1df
[ 1106.400020] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800438a0a00
[ 1106.400020] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 1106.400020] FS:  00007f7dfa7d7740(0000) GS:ffff88005da00000(0000) knlGS:0000000000000000
[ 1106.400020] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1106.400020] CR2: 0000000000000000 CR3: 000000003763e000 CR4: 00000000000006f0
[ 1106.400020] Stack:
[ 1106.400020]  ffff8800438a0a00 ffff88002917fdf8 0000000000000000 ffff88002917fd98
[ 1106.400020]  ffffffff812a1030 ffff8800438a0a00 ffff88002917fdf8 0000000000000000
[ 1106.400020]  0000000000000000 ffff88002917fde0 ffffffff8116d08a ffff88002917fdc8
[ 1106.400020] Call Trace:
[ 1106.400020]  [<ffffffff812a1030>] security_inode_setxattr+0x5d/0x6a
[ 1106.400020]  [<ffffffff8116d08a>] vfs_setxattr+0x6b/0x9f
[ 1106.400020]  [<ffffffff8116d1e0>] setxattr+0x122/0x16c
[ 1106.400020]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[ 1106.400020]  [<ffffffff8114d011>] ? __sb_start_write+0x10f/0x143
[ 1106.400020]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[ 1106.400020]  [<ffffffff811687c0>] ? __mnt_want_write+0x48/0x4f
[ 1106.400020]  [<ffffffff8116d3e6>] SyS_setxattr+0x6e/0xb0
[ 1106.400020]  [<ffffffff81529da9>] system_call_fastpath+0x16/0x1b
[ 1106.400020] Code: c3 0f 1f 44 00 00 55 48 89 e5 41 55 49 89 d5 41 54 49 89 fc 53 48 89 f3 48 c7 c6 d3 36 81 81 48 89 df e8 18 22 04 00 85 c0 75 07 <41> 80 7d 00 02 74 0d 48 89 de 4c 89 e7 e8 5a fe ff ff eb 03 83
[ 1106.400020] RIP  [<ffffffff812af7b8>] evm_inode_setxattr+0x2a/0x48
[ 1106.400020]  RSP <ffff88002917fd50>
[ 1106.400020] CR2: 0000000000000000
[ 1106.428061] ---[ end trace ae08331628ba3050 ]---

Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-28 10:06:31 -04:00
Dmitry Kasatkin
a48fda9de9 ima: check xattr value length and type in the ima_inode_setxattr()
ima_inode_setxattr() can be called with no value. Function does not
check the length so that following command can be used to produce
kernel oops: setfattr -n security.ima FOO. This patch fixes it.

Changes in v3:
* for stable reverted "allow setting hash only in fix or log mode"
  It will be a separate patch.

Changes in v2:
* testing validity of xattr type
* allow setting hash only in fix or log mode (Mimi)

[  261.562522] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  261.564109] IP: [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a
[  261.564109] PGD 3112f067 PUD 42965067 PMD 0
[  261.564109] Oops: 0000 [#1] SMP
[  261.564109] Modules linked in: bridge stp llc evdev serio_raw i2c_piix4 button fuse
[  261.564109] CPU: 0 PID: 3299 Comm: setxattr Not tainted 3.16.0-kds+ #2924
[  261.564109] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  261.564109] task: ffff8800428c2430 ti: ffff880042be0000 task.ti: ffff880042be0000
[  261.564109] RIP: 0010:[<ffffffff812af272>]  [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a
[  261.564109] RSP: 0018:ffff880042be3d50  EFLAGS: 00010246
[  261.564109] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000015
[  261.564109] RDX: 0000001500000000 RSI: 0000000000000000 RDI: ffff8800375cc600
[  261.564109] RBP: ffff880042be3d68 R08: 0000000000000000 R09: 00000000004d6256
[  261.564109] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88002149ba00
[  261.564109] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  261.564109] FS:  00007f6c1e219740(0000) GS:ffff88005da00000(0000) knlGS:0000000000000000
[  261.564109] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  261.564109] CR2: 0000000000000000 CR3: 000000003b35a000 CR4: 00000000000006f0
[  261.564109] Stack:
[  261.564109]  ffff88002149ba00 ffff880042be3df8 0000000000000000 ffff880042be3d98
[  261.564109]  ffffffff812a101b ffff88002149ba00 ffff880042be3df8 0000000000000000
[  261.564109]  0000000000000000 ffff880042be3de0 ffffffff8116d08a ffff880042be3dc8
[  261.564109] Call Trace:
[  261.564109]  [<ffffffff812a101b>] security_inode_setxattr+0x48/0x6a
[  261.564109]  [<ffffffff8116d08a>] vfs_setxattr+0x6b/0x9f
[  261.564109]  [<ffffffff8116d1e0>] setxattr+0x122/0x16c
[  261.564109]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[  261.564109]  [<ffffffff8114d011>] ? __sb_start_write+0x10f/0x143
[  261.564109]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[  261.564109]  [<ffffffff811687c0>] ? __mnt_want_write+0x48/0x4f
[  261.564109]  [<ffffffff8116d3e6>] SyS_setxattr+0x6e/0xb0
[  261.564109]  [<ffffffff81529da9>] system_call_fastpath+0x16/0x1b
[  261.564109] Code: 48 89 f7 48 c7 c6 58 36 81 81 53 31 db e8 73 27 04 00 85 c0 75 28 bf 15 00 00 00 e8 8a a5 d9 ff 84 c0 75 05 83 cb ff eb 15 31 f6 <41> 80 7d 00 03 49 8b 7c 24 68 40 0f 94 c6 e8 e1 f9 ff ff 89 d8
[  261.564109] RIP  [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a
[  261.564109]  RSP <ffff880042be3d50>
[  261.564109] CR2: 0000000000000000
[  261.599998] ---[ end trace 39a89a3fc267e652 ]---

Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-28 10:03:49 -04:00
Behan Webster
357aabed62 security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c
Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using a char array using the SHASH_DESC_ON_STACK macro.

The new code can be compiled with both gcc and clang.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Cc: tglx@linutronix.de
2014-10-14 10:51:24 +02:00
Roberto Sassu
c2426d2ad5 ima: added support for new kernel cmdline parameter ima_template_fmt
This patch allows users to provide a custom template format through the
new kernel command line parameter 'ima_template_fmt'. If the supplied
format is not valid, IMA uses the default template descriptor.

Changelog:
 - v3:
   - added check for 'fields' and 'num_fields' in
     template_desc_init_fields() (suggested by Mimi Zohar)

 - v2:
   - using template_desc_init_fields() to validate a format string
     (Roberto Sassu)
   - updated documentation by stating that only the chosen template
     descriptor is initialized (Roberto Sassu)

 - v1:
   - simplified code of ima_template_fmt_setup()
     (Roberto Sassu, suggested by Mimi Zohar)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-13 08:39:02 -04:00
Roberto Sassu
1bd7face74 ima: allocate field pointers array on demand in template_desc_init_fields()
The allocation of a field pointers array is moved at the end of
template_desc_init_fields() and done only if the value of the 'fields'
and 'num_fields' parameters is not NULL. For just validating a template
format string, retrieved template field pointers are placed in a temporary
array.

Changelog:
 - v3:
   - do not check in this patch if 'fields' and 'num_fields' are NULL
     (suggested by Mimi Zohar)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-13 08:39:02 -04:00
Roberto Sassu
9f3166b8ca ima: don't allocate a copy of template_fmt in template_desc_init_fields()
This patch removes the allocation of a copy of 'template_fmt', needed for
iterating over all fields in the passed template format string. The removal
was possible by replacing strcspn(), which modifies the passed string,
with strchrnul(). The currently processed template field is copied in
a temporary variable.

The purpose of this change is use template_desc_init_fields() in two ways:
for just validating a template format string (the function should work
if called by a setup function, when memory cannot be allocated), and for
actually initializing a template descriptor. The implementation of this
feature will be complete with the next patch.

Changelog:
 - v3:
   - added 'goto out' in template_desc_init_fields() to free allocated
     memory if a template field length is not valid (suggested by
     Mimi Zohar)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-13 08:39:01 -04:00
Roberto Sassu
7dbdb4206b ima: display template format in meas. list if template name length is zero
With the introduction of the 'ima_template_fmt' kernel cmdline parameter,
a user can define a new template descriptor with custom format. However,
in this case, userspace tools will be unable to parse the measurements
list because the new template is unknown. For this reason, this patch
modifies the current IMA behavior to display in the list the template
format instead of the name (only if the length of the latter is zero)
so that a tool can extract needed information if it can handle listed
fields.

This patch also correctly displays the error log message in
ima_init_template() if the selected template cannot be initialized.

Changelog:
 - v3:
   - check the first byte of 'e->template_desc->name' instead of using
     strlen() in ima_fs.c (suggested by Mimi Zohar)

 - v2:
   - print the template format in ima_init_template(), if the selected
     template is custom (Roberto Sassu)

 - v1:
   - fixed patch description (Roberto Sassu, suggested by Mimi Zohar)
   - set 'template_name' variable in ima_fs.c only once
     (Roberto Sassu, suggested by Mimi Zohar)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-13 08:39:01 -04:00
Roberto Sassu
71fed2eee0 ima: added error messages to template-related functions
This patch adds some error messages to inform users about the following
events: template descriptor not found, invalid template descriptor,
template field not found and template initialization failed.

Changelog:
 - v2:
   - display an error message if the format string contains too many
     fields (Roberto Sassu)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-13 08:39:01 -04:00
Dmitry Kasatkin
0716abbb58 ima: use atomic bit operations to protect policy update interface
The current implementation uses an atomic counter to provide exclusive
access to the sysfs 'policy' entry to update the IMA policy. While it is
highly unlikely, the usage of a counter might potentially allow another
process to overflow the counter, open the interface and insert additional
rules into the policy being loaded.

This patch replaces using an atomic counter with atomic bit operations
which is more reliable and a widely used method to provide exclusive access.

As bit operation keep the interface locked after successful update, it makes
it unnecessary to verify if the default policy was set or not during parsing
and interface closing. This patch also removes that code.

Changes in v3:
* move audit log message to ima_relead_policy() to report successful and
  unsuccessful result
* unnecessary comment removed

Changes in v2:
* keep interface locked after successful policy load as in original design
* remove sysfs entry as in original design

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-11 23:33:02 -04:00
Dmitry Kasatkin
7178784f0a ima: ignore empty and with whitespaces policy lines
Empty policy lines cause parsing failures which is, especially
for new users, hard to spot. This patch prevents it.

Changes in v2:
* strip leading blanks and tabs in rules to prevent parsing failures

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-11 23:29:19 -04:00
Dmitry Kasatkin
272a6e90ff ima: no need to allocate entry for comment
If a rule is a comment, there is no need to allocate an entry.
Move the checking for comments before allocating the entry.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-11 23:28:07 -04:00
Dmitry Kasatkin
78bb5d0b4f ima: report policy load status
Audit messages are rate limited, often causing the policy update
info to not be visible.  Report policy loading status also using
pr_info.

Changes in v2:
* reporting moved to ima_release_policy to notice parsing errors
* reporting both completed and failed status

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-11 23:25:25 -04:00
Dmitry Kasatkin
456f5fd3f6 ima: use path names cache
__getname() uses slab allocation which is faster than kmalloc.
Make use of it.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-07 14:32:54 -04:00
Dmitry Kasatkin
c2baec7ffa evm: skip replacing EVM signature with HMAC on read-only filesystem
If filesystem is mounted read-only or file is immutable, updating
xattr will fail. This is a usual case during early boot until
filesystem is remount read-write. This patch verifies conditions
to skip unnecessary attempt to calculate HMAC and set xattr.

Changes in v2:
* indention changed according to Lindent (requested by Mimi)

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-07 14:32:53 -04:00
Dmitry Kasatkin
d16a8585d3 integrity: add missing '__init' keyword for integrity_init_keyring()
integrity_init_keyring() is used only from kernel '__init'
functions. Add it there as well.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-07 14:32:53 -04:00
Dmitry Kasatkin
0f34a0060a ima: check ima_policy_flag in the ima_file_free() hook
This patch completes the switching to the 'ima_policy_flag' variable
in the checks at the beginning of IMA functions, starting with the
commit a756024e.

Checking 'iint_initialized' is completely unnecessary, because
S_IMA flag is unset if iint was not allocated. At the same time
the integrity cache is allocated with SLAB_PANIC and the kernel will
panic if the allocation fails during kernel initialization. So on
a running system iint_initialized is always true and can be removed.

Changes in v3:
* not limiting test to IMA_APPRAISE (spotted by Roberto Sassu)

Changes in v2:
* 'iint_initialized' removal patch merged to this patch (requested
   by Mimi)

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: Roberto Sassu <roberto.sassu@polito.it>
2014-10-07 14:32:52 -04:00
Dmitry Kasatkin
594081ee71 integrity: do zero padding of the key id
Latest KEYS code return error if hexadecimal string length id odd.
Fix it.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2014-10-06 17:33:27 +01:00
Roberto Sassu
1b68bdf9cd ima: detect violations for mmaped files
This patch fixes the detection of the 'open_writers' violation for mmaped
files.

before) an 'open_writers' violation is detected if the policy contains
        a rule with the criteria: func=FILE_CHECK mask=MAY_READ

after) an 'open_writers' violation is detected if the current event
       matches one of the policy rules.

With the old behaviour, the 'open_writers' violation is not detected
in the following case:

policy:
measure func=FILE_MMAP mask=MAY_EXEC

steps:
1) open a shared library for writing
2) execute a binary that links that shared library
3) during the binary execution, modify the shared library and save
   the change

result:
the 'open_writers' violation measurement is not present in the IMA list.

Only binaries executed are protected from writes. For libraries mapped
in memory there is the flag MAP_DENYWRITE for this purpose, but according
to the output of 'man mmap', the mmap flag is ignored.

Since ima_rdwr_violation_check() is now called by process_measurement()
the information about if the inode must be measured is already provided
by ima_get_action(). Thus the unnecessary function ima_must_measure()
has been removed.

Changes in v3 (Dmitry Kasatkin):
- Violation for MMAP_CHECK function are verified since this patch
- Changed patch description a bit

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-18 10:04:12 -04:00
Roberto Sassu
f7a859ff73 ima: fix race condition on ima_rdwr_violation_check and process_measurement
This patch fixes a race condition between two functions that try to access
the same inode. Since the i_mutex lock is held and released separately
in the two functions, there may be the possibility that a violation is
not correctly detected.

Suppose there are two processes, A (reader) and B (writer), if the
following sequence happens:

A: ima_rdwr_violation_check()
B: ima_rdwr_violation_check()
B: process_measurement()
B: starts writing the inode
A: process_measurement()

the ToMToU violation (a reader may be accessing a content different from
that measured, due to a concurrent modification by a writer) will not be
detected. To avoid this issue, the violation check and the measurement
must be done atomically.

This patch fixes the problem by moving the violation check inside
process_measurement() when the i_mutex lock is held. Differently from
the old code, the violation check is executed also for the MMAP_CHECK
hook (other than for FILE_CHECK). This allows to detect ToMToU violations
that are possible because shared libraries can be opened for writing
while they are in use (according to the output of 'man mmap', the mmap()
flag MAP_DENYWRITE is ignored).

Changes in v5 (Roberto Sassu):
* get iint if action is not zero
* exit process_measurement() after the violation check if action is zero
* reverse order process_measurement() exit cleanup (Mimi)

Changes in v4 (Dmitry Kasatkin):
* iint allocation is done before calling ima_rdrw_violation_check()
  (Suggested-by Mimi)
* do not check for violations if the policy does not contain 'measure'
  rules (done by Roberto Sassu)

Changes in v3 (Dmitry Kasatkin):
* no violation checking for MMAP_CHECK function in this patch
* remove use of filename from violation
* removes checking if ima is enabled from ima_rdrw_violation_check
* slight style change

Suggested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-18 10:03:55 -04:00
Roberto Sassu
a756024efe ima: added ima_policy_flag variable
This patch introduces the new variable 'ima_policy_flag', whose bits
are set depending on the action of the current policy rules. Only the
flags IMA_MEASURE, IMA_APPRAISE and IMA_AUDIT are set.

The new variable will be used to improve performance by skipping the
unnecessary execution of IMA code if the policy does not contain rules
with the above actions.

Changes in v6 (Roberto Sassu)
* do not check 'ima_initialized' before calling ima_update_policy_flag()
  in ima_update_policy() (suggested by Dmitry)
* calling ima_update_policy_flag() moved to init_ima to co-locate with
  ima_initialized (Dmitry)
* add/revise comments (Mimi)

Changes in v5 (Roberto Sassu)
* reset IMA_APPRAISE flag in 'ima_policy_flag' if 'ima_appraise' is set
  to zero (reported by Dmitry)
* update 'ima_policy_flag' only if IMA initialization is successful
  (suggested by Mimi and Dmitry)
* check 'ima_policy_flag' instead of 'ima_initialized'
  (suggested by Mimi and Dmitry)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17 16:39:36 -04:00
Roberto Sassu
be39ffc2fe ima: return an error code from ima_add_boot_aggregate()
This patch modifies ima_add_boot_aggregate() to return an error code.
This way we can determine if all the initialization procedures have
been executed successfully.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17 16:15:42 -04:00
Dmitry Kasatkin
2faa6ef3b2 ima: provide 'ima_appraise=log' kernel option
The kernel boot parameter "ima_appraise" currently defines 'off',
'enforce' and 'fix' modes.  When designing a policy and labeling
the system, access to files are either blocked in the default
'enforce' mode or automatically fixed in the 'fix' mode.  It is
beneficial to be able to run the system in a logging only mode,
without fixing it, in order to properly analyze the system. This
patch adds a 'log' mode to run the system in a permissive mode and
log the appraisal results.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17 16:14:23 -04:00
Dmitry Kasatkin
31b70f6632 ima: move keyring initialization to ima_init()
ima_init() is used as a single place for all initializations.
Experimental keyring patches used the 'late_initcall' which was
co-located with the late_initcall(init_ima). When the late_initcall
for the keyring initialization was abandoned, initialization moved
to init_ima, though it would be more logical to move it to ima_init,
where the rest of the initialization is done. This patch moves the
keyring initialization to ima_init() as a preparatory step for
loading the keys which will be added to ima_init() in following
patches.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17 16:10:59 -04:00
Dmitry Kasatkin
a2d61ed525 integrity: make integrity files as 'integrity' module
The kernel print macros use the KBUILD_MODNAME, which is initialized
to the module name. The current integrity/Makefile makes every file
as its own module, so pr_xxx messages are prefixed with the file name
instead of the module.  Similar to the evm/Makefile and ima/Makefile,
this patch fixes the integrity/Makefile to use the single name
'integrity'.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09 10:28:58 -04:00