linux-stable.git/security/integrity/ima, branch linux-5.10.y

ima: Handle error code returned by ima_filter_rule_match()

2026-01-19T12:11:33+00:00

[ Upstream commit 738c9738e690f5cea24a3ad6fd2d9a323cf614f6 ]

In ima_match_rules(), if ima_filter_rule_match() returns -ENOENT due to
the rule being NULL, the function incorrectly skips the 'if (!rc)' check
and sets 'result = true'. The LSM rule is considered a match, causing
extra files to be measured by IMA.

This issue can be reproduced in the following scenario:
After unloading the SELinux policy module via 'semodule -d', if an IMA
measurement is triggered before ima_lsm_rules is updated,
in ima_match_rules(), the first call to ima_filter_rule_match() returns
-ESTALE. This causes the code to enter the 'if (rc == -ESTALE &&
!rule_reinitialized)' block, perform ima_lsm_copy_rule() and retry. In
ima_lsm_copy_rule(), since the SELinux module has been removed, the rule
becomes NULL, and the second call to ima_filter_rule_match() returns
-ENOENT. This bypasses the 'if (!rc)' check and results in a false match.

Call trace:
  selinux_audit_rule_match+0x310/0x3b8
  security_audit_rule_match+0x60/0xa0
  ima_match_rules+0x2e4/0x4a0
  ima_match_policy+0x9c/0x1e8
  ima_get_action+0x48/0x60
  process_measurement+0xf8/0xa98
  ima_bprm_check+0x98/0xd8
  security_bprm_check+0x5c/0x78
  search_binary_handler+0x6c/0x318
  exec_binprm+0x58/0x1b8
  bprm_execve+0xb8/0x130
  do_execveat_common.isra.0+0x1a8/0x258
  __arm64_sys_execve+0x48/0x68
  invoke_syscall+0x50/0x128
  el0_svc_common.constprop.0+0xc8/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x44/0x200
  el0t_64_sync_handler+0x100/0x130
  el0t_64_sync+0x3c8/0x3d0

Fix this by changing 'if (!rc)' to 'if (rc <= 0)' to ensure that error
codes like -ENOENT do not bypass the check and accidentally result in a
successful match.

Fixes: 4af4662fa4a9d ("integrity: IMA policy")
Signed-off-by: Zhao Yipeng 
Reviewed-by: Roberto Sassu 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

ima: Fix use-after-free on a dentry's dname.name

2025-03-13T11:47:24+00:00

commit be84f32bb2c981ca670922e047cdde1488b233de upstream.

->d_name.name can change on rename and the earlier value can be freed;
there are conditions sufficient to stabilize it (->d_lock on dentry,
->d_lock on its parent, ->i_rwsem exclusive on the parent's inode,
rename_lock), but none of those are met at any of the sites. Take a stable
snapshot of the name instead.

Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/
Signed-off-by: Al Viro 
Signed-off-by: Stefan Berger 
Signed-off-by: Mimi Zohar 
[ Samasth: bp to fix CVE-2024-39494; Minor conflict resolved due to code context change ]
Signed-off-by: Samasth Norway Ananda 
Signed-off-by: Greg Kroah-Hartman

ima: Avoid blocking in RCU read-side critical section

2024-07-18T11:05:44+00:00

commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream.

A panic happens in ima_match_policy:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 42f873067 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
Kdump: loaded Tainted: P
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
               BIOS 0.0.0 02/06/2015
RIP: 0010:ima_match_policy+0x84/0x450
Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
      7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
      f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
      44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
FS:  00007f5195b51740(0000)
GS:ff3e278b12d40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ima_get_action+0x22/0x30
 process_measurement+0xb0/0x830
 ? page_add_file_rmap+0x15/0x170
 ? alloc_set_pte+0x269/0x4c0
 ? prep_new_page+0x81/0x140
 ? simple_xattr_get+0x75/0xa0
 ? selinux_file_open+0x9d/0xf0
 ima_file_check+0x64/0x90
 path_openat+0x571/0x1720
 do_filp_open+0x9b/0x110
 ? page_counter_try_charge+0x57/0xc0
 ? files_cgroup_alloc_fd+0x38/0x60
 ? __alloc_fd+0xd4/0x250
 ? do_sys_open+0x1bd/0x250
 do_sys_open+0x1bd/0x250
 do_syscall_64+0x5d/0x1d0
 entry_SYSCALL_64_after_hwframe+0x65/0xca

Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by
ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a
RCU read-side critical section which contains kmalloc with GFP_KERNEL.
This implies a possible sleep and violates limitations of RCU read-side
critical sections on non-PREEMPT systems.

Sleeping within RCU read-side critical section might cause
synchronize_rcu() returning early and break RCU protection, allowing a
UAF to happen.

The root cause of this issue could be described as follows:
|	Thread A	|	Thread B	|
|			|ima_match_policy	|
|			|  rcu_read_lock	|
|ima_lsm_update_rule	|			|
|  synchronize_rcu	|			|
|			|    kmalloc(GFP_KERNEL)|
|			|      sleep		|
==> synchronize_rcu returns early
|  kfree(entry)		|			|
|			|    entry = entry->next|
==> UAF happens and entry now becomes NULL (or could be anything).
|			|    entry->action	|
==> Accessing entry might cause panic.

To fix this issue, we are converting all kmalloc that is called within
RCU read-side critical section to use GFP_ATOMIC.

Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
Cc: stable@vger.kernel.org
Signed-off-by: GUO Zihua 
Acked-by: John Johansen 
Reviewed-by: Mimi Zohar 
Reviewed-by: Casey Schaufler 
[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
Signed-off-by: Paul Moore 
Signed-off-by: Roberto Sassu 
Signed-off-by: Greg Kroah-Hartman

ima: fix deadlock when traversing "ima_default_rules".

2024-05-25T14:19:06+00:00

commit eb0782bbdfd0d7c4786216659277c3fd585afc0e upstream.

The current IMA ruleset is identified by the variable "ima_rules"
that default to "&ima_default_rules". When loading a custom policy
for the first time, the variable is updated to "&ima_policy_rules"
instead. That update isn't RCU-safe, and deadlocks are possible.
Indeed, some functions like ima_match_policy() may loop indefinitely
when traversing "ima_default_rules" with list_for_each_entry_rcu().

When iterating over the default ruleset back to head, if the list
head is "ima_default_rules", and "ima_rules" have been updated to
"&ima_policy_rules", the loop condition (&entry->list != ima_rules)
stays always true, traversing won't terminate, causing a soft lockup
and RCU stalls.

Introduce a temporary value for "ima_rules" when iterating over
the ruleset to avoid the deadlocks.

Signed-off-by: liqiong 
Reviewed-by: THOBY Simon 
Fixes: 38d859f991f3 ("IMA: policy can now be updated multiple times")
Reported-by: kernel test robot  (Fix sparse: incompatible types in comparison expression.)
Signed-off-by: Mimi Zohar 
Signed-off-by: GUO Zihua 
Signed-off-by: Greg Kroah-Hartman

ima: detect changes to the backing overlay file

2023-11-28T16:54:57+00:00

commit b836c4d29f2744200b2af41e14bf50758dddc818 upstream.

Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for
IMA") forced signature re-evaulation on every file access.

Instead of always re-evaluating the file's integrity, detect a change
to the backing file, by comparing the cached file metadata with the
backing file's metadata.  Verifying just the i_version has not changed
is insufficient.  In addition save and compare the i_ino and s_dev
as well.

Reviewed-by: Amir Goldstein 
Tested-by: Eric Snowberg 
Tested-by: Raul E Rangel 
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

ima: rework CONFIG_IMA dependency block

2023-10-10T19:53:38+00:00

[ Upstream commit 91e326563ee34509c35267808a4b1b3ea3db62a8 ]

Changing the direct dependencies of IMA_BLACKLIST_KEYRING and
IMA_LOAD_X509 caused them to no longer depend on IMA, but a
a configuration without IMA results in link failures:

arm-linux-gnueabi-ld: security/integrity/iint.o: in function `integrity_load_keys':
iint.c:(.init.text+0xd8): undefined reference to `ima_load_x509'

aarch64-linux-ld: security/integrity/digsig_asymmetric.o: in function `asymmetric_verify':
digsig_asymmetric.c:(.text+0x104): undefined reference to `ima_blacklist_keyring'

Adding explicit dependencies on IMA would fix this, but a more reliable
way to do this is to enclose the entire Kconfig file in an 'if IMA' block.
This also allows removing the existing direct dependencies.

Fixes: be210c6d3597f ("ima: Finish deprecation of IMA_TRUSTED_KEYRING Kconfig")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

ima: Finish deprecation of IMA_TRUSTED_KEYRING Kconfig

2023-10-10T19:53:37+00:00

[ Upstream commit be210c6d3597faf330cb9af33b9f1591d7b2a983 ]

The removal of IMA_TRUSTED_KEYRING made IMA_LOAD_X509
and IMA_BLACKLIST_KEYRING unavailable because the latter
two depend on the former. Since IMA_TRUSTED_KEYRING was
deprecated in favor of INTEGRITY_TRUSTED_KEYRING use it
as a dependency for the two Kconfigs affected by the
deprecation.

Fixes: 5087fd9e80e5 ("ima: Remove deprecated IMA_TRUSTED_KEYRING Kconfig")
Signed-off-by: Oleksandr Tymoshenko 
Reviewed-by: Nayna Jain 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

ima: Remove deprecated IMA_TRUSTED_KEYRING Kconfig

2023-09-19T10:20:12+00:00

[ Upstream commit 5087fd9e80e539d2163accd045b73da64de7de95 ]

Time to remove "IMA_TRUSTED_KEYRING".

Fixes: f4dc37785e9b ("integrity: define '.evm' as a builtin 'trusted' keyring") # v4.5+
Signed-off-by: Nayna Jain 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

IMA: allow/fix UML builds

2023-08-26T13:26:46+00:00

[ Upstream commit 644f17412f5acf01a19af9d04a921937a2bc86c6 ]

UML supports HAS_IOMEM since 0bbadafdc49d (um: allow disabling
NO_IOMEM).

Current IMA build on UML fails on allmodconfig (with TCG_TPM=m):

ld: security/integrity/ima/ima_queue.o: in function `ima_add_template_entry':
ima_queue.c:(.text+0x2d9): undefined reference to `tpm_pcr_extend'
ld: security/integrity/ima/ima_init.o: in function `ima_init':
ima_init.c:(.init.text+0x43f): undefined reference to `tpm_default_chip'
ld: security/integrity/ima/ima_crypto.o: in function `ima_calc_boot_aggregate_tfm':
ima_crypto.c:(.text+0x1044): undefined reference to `tpm_pcr_read'
ld: ima_crypto.c:(.text+0x10d8): undefined reference to `tpm_pcr_read'

Modify the IMA Kconfig entry so that it selects TCG_TPM if HAS_IOMEM
is set, regardless of the UML Kconfig setting.
This updates TCG_TPM from =m to =y and fixes the linker errors.

Fixes: f4a0391dfa91 ("ima: fix Kconfig dependencies")
Cc: Stable  # v5.14+
Signed-off-by: Randy Dunlap 
Cc: Fabio Estevam 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: Johannes Berg 
Cc: linux-um@lists.infradead.org
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

ima: Fix build warnings

2023-07-27T06:43:35+00:00

[ Upstream commit 95526d13038c2bbddd567a4d8e39fac42484e182 ]

Fix build warnings (function parameters description) for
ima_collect_modsig(), ima_match_policy() and ima_parse_add_rule().

Fixes: 15588227e086 ("ima: Collect modsig") # v5.4+
Fixes: 2fe5d6def167 ("ima: integrity appraisal extension") # v5.14+
Fixes: 4af4662fa4a9 ("integrity: IMA policy") # v3.2+
Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin