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  1. 14 9月, 2012 1 次提交
  3. 12 9月, 2012 5 次提交
  5. 08 9月, 2012 10 次提交
    • D
      ima: digital signature verification support · 8606404f
      由 Dmitry Kasatkin 提交于 
      This patch adds support for digital signature based integrity appraisal.
With this patch, 'security.ima' contains either the file data hash or
a digital signature of the file data hash. The file data hash provides
the security attribute of file integrity. In addition to file integrity,
a digital signature provides the security attribute of authenticity.

Unlike EVM, when the file metadata changes, the digital signature is
replaced with an HMAC, modification of the file data does not cause the
'security.ima' digital signature to be replaced with a hash. As a
result, after any modification, subsequent file integrity appraisals
would fail.

Although digitally signed files can be modified, but by not updating
'security.ima' to reflect these modifications, in essence digitally
signed files could be considered 'immutable'.

IMA uses a different keyring than EVM. While the EVM keyring should not
be updated after initialization and locked, the IMA keyring should allow
updating or adding new keys when upgrading or installing packages.

Changelog v4:
- Change IMA_DIGSIG to hex equivalent
Changelog v3:
- Permit files without any 'security.ima' xattr to be labeled properly.
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
      8606404f
    • M
      ima: add support for different security.ima data types · 5a44b412
      由 Mimi Zohar 提交于 
      IMA-appraisal currently verifies the integrity of a file based on a
known 'good' measurement value.  This patch reserves the first byte
of 'security.ima' as a place holder for the type of method used for
verifying file data integrity.

Changelog v1:
- Use the newly defined 'struct evm_ima_xattr_data'
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
      5a44b412
    • M
      ima: add ima_inode_setxattr/removexattr function and calls · 42c63330
      由 Mimi Zohar 提交于 
      Based on xattr_permission comments, the restriction to modify 'security'
xattr is left up to the underlying fs or lsm. Ensure that not just anyone
can modify or remove 'security.ima'.

Changelog v1:
- Unless IMA-APPRAISE is configured, use stub ima_inode_removexattr()/setxattr()
  functions.  (Moved ima_inode_removexattr()/setxattr() to ima_appraise.c)

Changelog:
  - take i_mutex to fix locking (Dmitry Kasatkin)
  - ima_reset_appraise_flags should only be called when modifying or
    removing the 'security.ima' xattr. Requires CAP_SYS_ADMIN privilege.
    (Incorporated fix from Roberto Sassu)
  - Even if allowed to update security.ima, reset the appraisal flags,
    forcing re-appraisal.
  - Replace CAP_MAC_ADMIN with CAP_SYS_ADMIN
  - static inline ima_inode_setxattr()/ima_inode_removexattr() stubs
  - ima_protect_xattr should be static
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
      42c63330
    • M
      ima: add inode_post_setattr call · 9957a504
      由 Mimi Zohar 提交于 
      Changing an inode's metadata may result in our not needing to appraise
the file.  In such cases, we must remove 'security.ima'.

Changelog v1:
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
      9957a504
    • D
      ima: replace iint spinblock with rwlock/read_lock · a10bf26b
      由 Dmitry Kasatkin 提交于 
      For performance, replace the iint spinlock with rwlock/read_lock.

Eric Paris questioned this change, from spinlocks to rwlocks, saying
"rwlocks have been shown to actually be slower on multi processor
systems in a number of cases due to the cache line bouncing required."

Based on performance measurements compiling the kernel on a cold
boot with multiple jobs with/without this patch, Dmitry Kasatkin
and I found that rwlocks performed better than spinlocks, but very
insignificantly.  For example with total compilation time around 6
minutes, with rwlocks time was 1 - 3 seconds shorter... but always
like that.

Changelog v2:
- new patch taken from the 'allocating iint improvements' patch
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
      a10bf26b
    • D
      ima: allocating iint improvements · bf2276d1
      由 Dmitry Kasatkin 提交于 
      With IMA-appraisal's removal of the iint mutex and taking the i_mutex
instead, allocating the iint becomes a lot simplier, as we don't need
to be concerned with two processes racing to allocate the iint. This
patch cleans up and improves performance for allocating the iint.

- removed redundant double i_mutex locking
- combined iint allocation with tree search

Changelog v2:
- removed the rwlock/read_lock changes from this patch
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
      bf2276d1
    • M
      ima: add appraise action keywords and default rules · 07f6a794
      由 Mimi Zohar 提交于 
      Unlike the IMA measurement policy, the appraise policy can not be dependent
on runtime process information, such as the task uid, as the 'security.ima'
xattr is written on file close and must be updated each time the file changes,
regardless of the current task uid.

This patch extends the policy language with 'fowner', defines an appraise
policy, which appraises all files owned by root, and defines 'ima_appraise_tcb',
a new boot command line option, to enable the appraise policy.

Changelog v3:
- separate the measure from the appraise rules in order to support measuring
  without appraising and appraising without measuring.
- change appraisal default for filesystems without xattr support to fail
- update default appraise policy for cgroups

Changelog v1:
- don't appraise RAMFS (Dmitry Kasatkin)
- merged rest of "ima: ima_must_appraise_or_measure API change" commit
  (Dmtiry Kasatkin)

  ima_must_appraise_or_measure() called ima_match_policy twice, which
  searched the policy for a matching rule.  Once for a matching measurement
  rule and subsequently for an appraisal rule. Searching the policy twice
  is unnecessary overhead, which could be noticeable with a large policy.

  The new version of ima_must_appraise_or_measure() does everything in a
  single iteration using a new version of ima_match_policy().  It returns
  IMA_MEASURE, IMA_APPRAISE mask.

  With the use of action mask only one efficient matching function
  is enough.  Removed other specific versions of matching functions.

Changelog:
- change 'owner' to 'fowner' to conform to the new LSM conditions posted by
  Roberto Sassu.
- fix calls to ima_log_string()
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
      07f6a794
    • M
      ima: integrity appraisal extension · 2fe5d6de
      由 Mimi Zohar 提交于 
      IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party.  The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'.  The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.

This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement.  Protection of the xattr is provided by
EVM, if enabled and configured.

Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.

Changelov v4:
- changed iint cache flags to hex values

Changelog v3:
- change appraisal default for filesystems without xattr support to fail

Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values

Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
  (INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
  'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
  (moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file

Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
  iint->mutex, and ima_file_free() and process_measurement(), which take
  the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
  only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
  not before.  (Found by Joe Perches)
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
      2fe5d6de
    • M
      vfs: move ima_file_free before releasing the file · 4199d35c
      由 Mimi Zohar 提交于 
      ima_file_free(), called on __fput(), currently flags files that have
changed, so that the file is re-measured.  For appraising a files's
integrity, the file's hash must be re-calculated and stored in the
'security.ima' xattr to reflect any changes.

This patch moves the ima_file_free() call to before releasing the file
in preparation of ima-appraisal measuring the file and updating the
'security.ima' xattr.
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
      4199d35c
    • M
      vfs: extend vfs_removexattr locking · 2ab51f37
      由 Mimi Zohar 提交于 
      This patch takes the i_mutex lock before security_inode_removexattr(),
instead of after, in preparation of calling ima_inode_removexattr().
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@nokia.com>
      2ab51f37
  7. 07 9月, 2012 1 次提交
  9. 06 9月, 2012 1 次提交
  11. 05 9月, 2012 1 次提交
  13. 23 8月, 2012 13 次提交
  15. 17 8月, 2012 8 次提交