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| author | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2014-05-12 09:28:11 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-26 15:15:38 -0400 |
| commit | ca7919db0c6dd616f2d1102f40fe7aacfd730121 (patch) | |
| tree | 84b37e7fc704bad01ab958ef7604d7ef760ecde6 /Documentation | |
| parent | 124067ae6606c2e9433a912b3c57fcc78b484362 (diff) | |
| download | lwn-ca7919db0c6dd616f2d1102f40fe7aacfd730121.tar.gz lwn-ca7919db0c6dd616f2d1102f40fe7aacfd730121.zip | |
ima: audit log files opened with O_DIRECT flag
commit f9b2a735bdddf836214b5dca74f6ca7712e5a08c upstream.
Files are measured or appraised based on the IMA policy. When a
file, in policy, is opened with the O_DIRECT flag, a deadlock
occurs.
The first attempt at resolving this lockdep temporarily removed the
O_DIRECT flag and restored it, after calculating the hash. The
second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this
flag, do_blockdev_direct_IO() would skip taking the i_mutex a second
time. The third attempt, by Dmitry Kasatkin, resolves the i_mutex
locking issue, by re-introducing the IMA mutex, but uncovered
another problem. Reading a file with O_DIRECT flag set, writes
directly to userspace pages. A second patch allocates a user-space
like memory. This works for all IMA hooks, except ima_file_free(),
which is called on __fput() to recalculate the file hash.
Until this last issue is addressed, do not 'collect' the
measurement for measuring, appraising, or auditing files opened
with the O_DIRECT flag set. Based on policy, permit or deny file
access. This patch defines a new IMA policy rule option named
'permit_directio'. Policy rules could be defined, based on LSM
or other criteria, to permit specific applications to open files
with the O_DIRECT flag set.
Changelog v1:
- permit or deny file access based IMA policy rules
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/ima_policy | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index f1c5cc9d17a8..4c3efe434806 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -23,7 +23,7 @@ Description: [fowner]] lsm: [[subj_user=] [subj_role=] [subj_type=] [obj_user=] [obj_role=] [obj_type=]] - option: [[appraise_type=]] + option: [[appraise_type=]] [permit_directio] base: func:= [BPRM_CHECK][MMAP_CHECK][FILE_CHECK][MODULE_CHECK] mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC] |