kernel/linux.git/security/integrity/ima, branch v3.18.62

ima: accept previously set IMA_NEW_FILE

2017-05-25T12:17:57+00:00

commit 1ac202e978e18f045006d75bd549612620c6ec3a upstream. Modifying the attributes of a file makes ima_inode_post_setattr reset the IMA cache flags. So if the file, which has just been created, is opened a second time before the first file descriptor is closed, verification fails since the security.ima xattr has not been written yet. We therefore have to look at the IMA_NEW_FILE even if the file already existed. With this patch there should no longer be an error when cat tries to open testfile: $ rm -f testfile $ ( echo test >&3 ; touch testfile ; cat testfile ) 3>testfile A file being new is no reason to accept that it is missing a digital signature demanded by the policy. Signed-off-by: Daniel Glöckner Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

ima: extend "mask" policy matching support

2015-08-27T17:25:53+00:00

[ Upstream commit 747cadeb108665b0474624a374aa9e13f12c9274 ] commit 4351c294b8c1028077280f761e158d167b592974 upstream. 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 Signed-off-by: Dr. Greg Wettstein Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

ima: add support for new "euid" policy condition

2015-08-27T17:25:52+00:00

[ Upstream commit 139069eff7388407f19794384c42a534d618ccd7 ] 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 Signed-off-by: Dr. Greg Wettstein Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

ima: fix ima_show_template_data_ascii()

2015-07-04T03:02:31+00:00

[ Upstream commit 45b26133b97871896b8c5241d59f4ff7839db7b2 ] 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 Signed-off-by: Roberto Sassu Cc: stable@vger.kernel.org # 3.13 Signed-off-by: Sasha Levin

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into for-linus

2014-10-29T04:03:54+00:00

ima: check xattr value length and type in the ima_inode_setxattr()

2014-10-28T14:03:49+00:00

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: [] 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:[] [] 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] [] security_inode_setxattr+0x48/0x6a [ 261.564109] [] vfs_setxattr+0x6b/0x9f [ 261.564109] [] setxattr+0x122/0x16c [ 261.564109] [] ? mnt_want_write+0x21/0x45 [ 261.564109] [] ? __sb_start_write+0x10f/0x143 [ 261.564109] [] ? mnt_want_write+0x21/0x45 [ 261.564109] [] ? __mnt_want_write+0x48/0x4f [ 261.564109] [] SyS_setxattr+0x6e/0xb0 [ 261.564109] [] 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 [] ima_inode_setxattr+0x3e/0x5a [ 261.564109] RSP [ 261.564109] CR2: 0000000000000000 [ 261.599998] ---[ end trace 39a89a3fc267e652 ]--- Reported-by: Jan Kara Signed-off-by: Dmitry Kasatkin Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar

security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c

2014-10-14T08:51:24+00:00

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 Reviewed-by: Mark Charlebois Reviewed-by: Jan-Simon Möller Acked-by: Herbert Xu Acked-by: Dmitry Kasatkin Cc: tglx@linutronix.de

ima: detect violations for mmaped files

2014-09-18T14:04:12+00:00

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 Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

ima: fix race condition on ima_rdwr_violation_check and process_measurement

2014-09-18T14:03:55+00:00

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 Signed-off-by: Roberto Sassu Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

ima: added ima_policy_flag variable

2014-09-17T20:39:36+00:00

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 Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar