If EVM is not supported or enabled, evm_verify_hmac() returns
INTEGRITY_UNKNOWN, which ima_appraise_measurement() ignores and sets
the appraisal status based solely on the security.ima verification.
evm_verify_hmac() also returns INTEGRITY_UNKNOWN for other failures, such
as temporary failures like -ENOMEM, resulting in possible attack vectors.
This patch changes the default return code for temporary/unexpected
failures, like -ENOMEM, from INTEGRITY_UNKNOWN to INTEGRITY_FAIL, making
evm_verify_hmac() fail safe.
As a result, failures need to be re-evaluated in order to catch both
temporary errors, such as the -ENOMEM, as well as errors that have been
resolved in fix mode.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Using shash is more efficient, because the algorithm is allocated only
once. Only the descriptor to store the hash state needs to be allocated
for every operation.
Changelog v6:
- check for crypto_shash_setkey failure
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Changelog v7:
- moved the initialization call to security_inode_init_security,
renaming evm_inode_post_init_security to evm_inode_init_security
- increase size of xattr array for EVM xattr
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Initialize 'security.evm' for new files.
Changelog v7:
- renamed evm_inode_post_init_security to evm_inode_init_security
- moved struct xattr definition to earlier patch
- allocate xattr name
Changelog v6:
- Use 'struct evm_ima_xattr_data'
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Imbed the evm calls evm_inode_setxattr(), evm_inode_post_setxattr(),
evm_inode_removexattr() in the security hooks. evm_inode_setxattr()
protects security.evm xattr. evm_inode_post_setxattr() and
evm_inode_removexattr() updates the hmac associated with an inode.
(Assumes an LSM module protects the setting/removing of xattr.)
Changelog:
- Don't define evm_verifyxattr(), unless CONFIG_INTEGRITY is enabled.
- xattr_name is a 'const', value is 'void *'
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
EVM protects a file's security extended attributes(xattrs) against integrity
attacks. The current patchset maintains an HMAC-sha1 value across the security
xattrs, storing the value as the extended attribute 'security.evm'. We
anticipate other methods for protecting the security extended attributes.
This patch reserves the first byte of 'security.evm' as a place holder for
the type of method.
Changelog v6:
- move evm_ima_xattr_type definition to security/integrity/integrity.h
- defined a structure for the EVM xattr called evm_ima_xattr_data
(based on Serge Hallyn's suggestion)
- removed unnecessary memset
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
EVM protects a file's security extended attributes(xattrs) against integrity
attacks. This patchset provides the framework and an initial method. The
initial method maintains an HMAC-sha1 value across the security extended
attributes, storing the HMAC value as the extended attribute 'security.evm'.
Other methods of validating the integrity of a file's metadata will be posted
separately (eg. EVM-digital-signatures).
While this patchset does authenticate the security xattrs, and
cryptographically binds them to the inode, coming extensions will bind other
directory and inode metadata for more complete protection. To help simplify
the review and upstreaming process, each extension will be posted separately
(eg. IMA-appraisal, IMA-appraisal-directory). For a general overview of the
proposed Linux integrity subsystem, refer to Dave Safford's whitepaper:
http://downloads.sf.net/project/linux-ima/linux-ima/Integrity_overview.pdf.
EVM depends on the Kernel Key Retention System to provide it with a
trusted/encrypted key for the HMAC-sha1 operation. The key is loaded onto the
root's keyring using keyctl. Until EVM receives notification that the key has
been successfully loaded onto the keyring (echo 1 > <securityfs>/evm), EVM can
not create or validate the 'security.evm' xattr, but returns INTEGRITY_UNKNOWN.
Loading the key and signaling EVM should be done as early as possible. Normally
this is done in the initramfs, which has already been measured as part of the
trusted boot. For more information on creating and loading existing
trusted/encrypted keys, refer to Documentation/keys-trusted-encrypted.txt. A
sample dracut patch, which loads the trusted/encrypted key and enables EVM, is
available from http://linux-ima.sourceforge.net/#EVM.
Based on the LSMs enabled, the set of EVM protected security xattrs is defined
at compile. EVM adds the following three calls to the existing security hooks:
evm_inode_setxattr(), evm_inode_post_setxattr(), and evm_inode_removexattr. To
initialize and update the 'security.evm' extended attribute, EVM defines three
calls: evm_inode_post_init(), evm_inode_post_setattr() and
evm_inode_post_removexattr() hooks. To verify the integrity of a security
xattr, EVM exports evm_verifyxattr().
Changelog v7:
- Fixed URL in EVM ABI documentation
Changelog v6: (based on Serge Hallyn's review)
- fix URL in patch description
- remove evm_hmac_size definition
- use SHA1_DIGEST_SIZE (removed both MAX_DIGEST_SIZE and evm_hmac_size)
- moved linux include before other includes
- test for crypto_hash_setkey failure
- fail earlier for invalid key
- clear entire encrypted key, even on failure
- check xattr name length before comparing xattr names
Changelog:
- locking based on i_mutex, remove evm_mutex
- using trusted/encrypted keys for storing the EVM key used in the HMAC-sha1
operation.
- replaced crypto hash with shash (Dmitry Kasatkin)
- support for additional methods of verifying the security xattrs
(Dmitry Kasatkin)
- iint not allocated for all regular files, but only for those appraised
- Use cap_sys_admin in lieu of cap_mac_admin
- Use __vfs_setxattr_noperm(), without permission checks, from EVM
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Move the inode integrity data(iint) management up to the integrity directory
in order to share the iint among the different integrity models.
Changelog:
- don't define MAX_DIGEST_SIZE
- rename several globally visible 'ima_' prefixed functions, structs,
locks, etc to 'integrity_'
- replace '20' with SHA1_DIGEST_SIZE
- reflect location change in appropriate Kconfig and Makefiles
- remove unnecessary initialization of iint_initialized to 0
- rebased on current ima_iint.c
- define integrity_iint_store/lock as static
There should be no other functional changes.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
This patch changes the security_inode_init_security API by adding a
filesystem specific callback to write security extended attributes.
This change is in preparation for supporting the initialization of
multiple LSM xattrs and the EVM xattr. Initially the callback function
walks an array of xattrs, writing each xattr separately, but could be
optimized to write multiple xattrs at once.
For existing security_inode_init_security() calls, which have not yet
been converted to use the new callback function, such as those in
reiserfs and ocfs2, this patch defines security_old_inode_init_security().
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Update comments for scripts/kernel-doc and fix some of errors reported by
scripts/checkpatch.pl .
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
This patch adds support for permission checks using argv[]/envp[] of execve()
request. Hooks are in the last patch of this pathset.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
This patch adds support for permission checks using executable file's realpath
upon execve() and symlink's target upon symlink(). Hooks are in the last patch
of this pathset.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
This patch adds support for permission checks using file object's DAC
attributes (e.g. owner/group) when checking file's pathnames. Hooks for passing
file object's pointers are in the last patch of this pathset.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
This patch adds support for permission checks using current thread's UID/GID
etc. in addition to pathnames.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
/sys/kernel/security/tomoyo/.domain_status can be easily emulated using
/sys/kernel/security/tomoyo/domain_policy . We can remove this interface by
updating /usr/sbin/tomoyo-setprofile utility.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
I forgot to add #ifndef in commit 0e4ae0e0 "TOMOYO: Make several options
configurable.", resulting
security/built-in.o: In function `tomoyo_bprm_set_creds':
tomoyo.c:(.text+0x4698e): undefined reference to `tomoyo_load_policy'
error.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor is masking the capabilities returned by capget against the
capabilities mask in the profile. This is wrong, in complain mode the
profile has effectively all capabilities, as the profile restrictions are
not being enforced, merely tested against to determine if an access is
known by the profile.
This can result in the wrong behavior of security conscience applications
like sshd which examine their capability set, and change their behavior
accordingly. In this case because of the masked capability set being
returned sshd fails due to DAC checks, even when the profile is in complain
mode.
Kernels affected: 2.6.36 - 3.0.
Signed-off-by: John Johansen <john.johansen@canonical.com>
The pointer returned from tracehook_tracer_task() is only valid inside
the rcu_read_lock. However the tracer pointer obtained is being passed
to aa_may_ptrace outside of the rcu_read_lock critical section.
Mover the aa_may_ptrace test into the rcu_read_lock critical section, to
fix this.
Kernels affected: 2.6.36 - 3.0
Reported-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@kernel.org
Signed-off-by: John Johansen <john.johansen@canonical.com>
To be able to start using enforcing mode from the early stage of boot sequence,
this patch adds support for activating access control without calling external
policy loader program. This will be useful for systems where operations which
can lead to the hijacking of the boot sequence are needed before loading the
policy. For example, you can activate immediately after loading the fixed part
of policy which will allow only operations needed for mounting a partition
which contains the variant part of policy and verifying (e.g. running GPG
check) and loading the variant part of policy. Since you can start using
enforcing mode from the beginning, you can reduce the possibility of hijacking
the boot sequence.
This patch makes several variables configurable on build time. This patch also
adds TOMOYO_loader= and TOMOYO_trigger= kernel command line option to boot the
same kernel in two different init systems (BSD-style init and systemd).
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
To be able to start using enforcing mode from the early stage of boot sequence,
this patch adds support for built-in policy configuration (and next patch adds
support for activating access control without calling external policy loader
program).
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Show statistics such as last policy update time and last policy violation time
in addition to memory usage.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Gather string constants to one file in order to make the object size smaller.
Use unsigned type where appropriate.
read()/write() returns ssize_t.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Currently TOMOYO holds SRCU lock upon open() and releases it upon close()
because list elements stored in the "struct tomoyo_io_buffer" instances are
accessed until close() is called. However, such SRCU usage causes lockdep to
complain about leaving the kernel with SRCU lock held.
This patch solves the warning by holding/releasing SRCU upon each
read()/write(). This patch is doing something similar to calling kfree()
without calling synchronize_srcu(), by selectively deferring kfree() by keeping
track of the "struct tomoyo_io_buffer" instances.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
TOMOYO wants to use /proc/self/ rather than /proc/$PID/ if $PID matches current
thread's process ID in order to prevent current thread from accessing other
process's information unless needed.
But since procfs can be mounted on various locations (e.g. /proc/ /proc2/ /p/
/tmp/foo/100/p/ ), TOMOYO cannot tell that whether the numeric part in the
string returned by __d_path() represents process ID or not.
Therefore, to be able to convert from $PID to self no matter where procfs is
mounted, this patch changes pathname representations for filesystems which do
not support rename() operation (e.g. proc, sysfs, securityfs).
Examples:
/proc/self/mounts => proc:/self/mounts
/sys/kernel/security/ => sys:/kernel/security/
/dev/pts/0 => devpts:/0
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Mauras Olivier reported that it is difficult to use TOMOYO in LXC environments,
for TOMOYO cannot distinguish between environments outside the container and
environments inside the container since LXC environments are created using
pivot_root(). To address this problem, this patch introduces policy namespace.
Each policy namespace has its own set of domain policy, exception policy and
profiles, which are all independent of other namespaces. This independency
allows users to develop policy without worrying interference among namespaces.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
ACL group allows administrator to globally grant not only "file read"
permission but also other permissions.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Add /sys/kernel/security/tomoyo/audit interface. This interface generates audit
logs in the form of domain policy so that /usr/sbin/tomoyo-auditd can reuse
audit logs for appending to /sys/kernel/security/tomoyo/domain_policy
interface.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Remove global preference from profile structure in order to make code simpler.
Due to this structure change, printk() warnings upon policy violation are
temporarily disabled. They will be replaced by
/sys/kernel/security/tomoyo/audit by next patch.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Convert "allow_..." style directives to "file ..." style directives.
By converting to the latter style, we can pack policy like
"file read/write/execute /path/to/file".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Use structure for passing ACL line, in preparation for supporting policy
namespace and conditional parameters.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Use common structure for ACL with "struct list_head" + "atomic_t".
Use array/struct where possible.
Remove is_group from "struct tomoyo_name_union"/"struct tomoyo_number_union".
Pass "struct file"->private_data rather than "struct file".
Update some of comments.
Bring tomoyo_same_acl_head() from common.h to domain.c .
Bring tomoyo_invalid()/tomoyo_valid() from common.h to util.c .
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Update (or temporarily remove) comments.
Remove or replace some of #define lines.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
In order to synchronize with TOMOYO 1.8's syntax,
(1) Remove special handling for allow_read/write permission.
(2) Replace deny_rewrite/allow_rewrite permission with allow_append permission.
(3) Remove file_pattern keyword.
(4) Remove allow_read permission from exception policy.
(5) Allow creating domains in enforcing mode without calling supervisor.
(6) Add permission check for opening directory for reading.
(7) Add permission check for stat() operation.
(8) Make "cat < /sys/kernel/security/tomoyo/self_domain" behave as if
"cat /sys/kernel/security/tomoyo/self_domain".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
The 'encrypted' key type defines its own payload format which contains a
symmetric key randomly generated that cannot be used directly to mount
an eCryptfs filesystem, because it expects an authentication token
structure.
This patch introduces the new format 'ecryptfs' that allows to store an
authentication token structure inside the encrypted key payload containing
a randomly generated symmetric key, as the same for the format 'default'.
More details about the usage of encrypted keys with the eCryptfs
filesystem can be found in the file 'Documentation/keys-ecryptfs.txt'.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch introduces a new parameter, called 'format', that defines the
format of data stored by encrypted keys. The 'default' format identifies
encrypted keys containing only the symmetric key, while other formats can
be defined to support additional information. The 'format' parameter is
written in the datablob produced by commands 'keyctl print' or
'keyctl pipe' and is integrity protected by the HMAC.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Some debug messages have been added in the function datablob_parse() in
order to better identify errors returned when dealing with 'encrypted'
keys.
Changelog from version v4:
- made the debug messages more understandable
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Do not dump the master key if an error is encountered during the request.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Fix error handling in construct_key_and_link().
If construct_alloc_key() returns an error, it shouldn't pass out through
the normal path as the key_serial() called by the kleave() statement
will oops when it gets an error code in the pointer:
BUG: unable to handle kernel paging request at ffffffffffffff84
IP: [<ffffffff8120b401>] request_key_and_link+0x4d7/0x52f
..
Call Trace:
[<ffffffff8120b52c>] request_key+0x41/0x75
[<ffffffffa00ed6e8>] cifs_get_spnego_key+0x206/0x226 [cifs]
[<ffffffffa00eb0c9>] CIFS_SessSetup+0x511/0x1234 [cifs]
[<ffffffffa00d9799>] cifs_setup_session+0x90/0x1ae [cifs]
[<ffffffffa00d9c02>] cifs_get_smb_ses+0x34b/0x40f [cifs]
[<ffffffffa00d9e05>] cifs_mount+0x13f/0x504 [cifs]
[<ffffffffa00caabb>] cifs_do_mount+0xc4/0x672 [cifs]
[<ffffffff8113ae8c>] mount_fs+0x69/0x155
[<ffffffff8114ff0e>] vfs_kern_mount+0x63/0xa0
[<ffffffff81150be2>] do_kern_mount+0x4d/0xdf
[<ffffffff81152278>] do_mount+0x63c/0x69f
[<ffffffff8115255c>] sys_mount+0x88/0xc2
[<ffffffff814fbdc2>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
devcgroup_inode_permission: take "is it a device node" checks to inlined wrapper
fix comment in generic_permission()
kill obsolete comment for follow_down()
proc_sys_permission() is OK in RCU mode
reiserfs_permission() doesn't need to bail out in RCU mode
proc_fd_permission() is doesn't need to bail out in RCU mode
nilfs2_permission() doesn't need to bail out in RCU mode
logfs doesn't need ->permission() at all
coda_ioctl_permission() is safe in RCU mode
cifs_permission() doesn't need to bail out in RCU mode
bad_inode_permission() is safe from RCU mode
ubifs: dereferencing an ERR_PTR in ubifs_mount()
inode_permission() calls devcgroup_inode_permission() and almost all such
calls are _not_ for device nodes; let's at least keep the common path
straight...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
____call_usermodehelper() now erases any credentials set by the
subprocess_inf::init() function. The problem is that commit
17f60a7da1 ("capabilites: allow the application of capability limits
to usermode helpers") creates and commits new credentials with
prepare_kernel_cred() after the call to the init() function. This wipes
all keyrings after umh_keys_init() is called.
The best way to deal with this is to put the init() call just prior to
the commit_creds() call, and pass the cred pointer to init(). That
means that umh_keys_init() and suchlike can modify the credentials
_before_ they are published and potentially in use by the rest of the
system.
This prevents request_key() from working as it is prevented from passing
the session keyring it set up with the authorisation token to
/sbin/request-key, and so the latter can't assume the authority to
instantiate the key. This causes the in-kernel DNS resolver to fail
with ENOKEY unconditionally.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Tested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When policy version is less than POLICYDB_VERSION_FILENAME_TRANS,
skip file_name_trans_write().
Signed-off-by: Roy.Li <rongqing.li@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
