kernel.git/security/integrity/ima/ima_policy.c, branch linux-5.4.y

ima: Fix build warnings

2023-07-27T06:37:06Z

[ 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

ima: Handle -ESTALE returned by ima_filter_rule_match()

2023-01-18T10:41:01Z

[ Upstream commit c7423dbdbc9ecef7fff5239d144cad4b9887f4de ] IMA relies on the blocking LSM policy notifier callback to update the LSM based IMA policy rules. When SELinux update its policies, IMA would be notified and starts updating all its lsm rules one-by-one. During this time, -ESTALE would be returned by ima_filter_rule_match() if it is called with a LSM rule that has not yet been updated. In ima_match_rules(), -ESTALE is not handled, and the LSM rule is considered a match, causing extra files to be measured by IMA. Fix it by re-initializing a temporary rule if -ESTALE is returned by ima_filter_rule_match(). The origin rule in the rule list would be updated by the LSM policy notifier callback. Fixes: b16942455193 ("ima: use the lsm policy update notifier") Signed-off-by: GUO Zihua Reviewed-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Fix fall-through warnings for Clang

2023-01-18T10:41:01Z

[ Upstream commit 28073eb09c5aa29e879490edb88cfd3e7073821e ] In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple warnings by explicitly adding multiple break statements instead of just letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva Signed-off-by: Mimi Zohar Stable-dep-of: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Signed-off-by: Sasha Levin

ima: Rename internal filter rule functions

2023-01-18T10:41:01Z

[ Upstream commit b8867eedcf76caef8ae6412da97cd9abfd092ff8 ] Rename IMA's internal filter rule functions from security_filter_rule_*() to ima_filter_rule_*(). This avoids polluting the security_* namespace, which is typically reserved for general security subsystem infrastructure. Signed-off-by: Tyler Hicks Suggested-by: Casey Schaufler [zohar@linux.ibm.com: reword using the term "filter", not "audit"] Signed-off-by: Mimi Zohar Stable-dep-of: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Signed-off-by: Sasha Levin

lockdown: Fix kexec lockdown bypass with ima policy

2022-07-29T15:14:09Z

commit 543ce63b664e2c2f9533d089a4664b559c3e6b5b upstream. The lockdown LSM is primarily used in conjunction with UEFI Secure Boot. This LSM may also be used on machines without UEFI. It can also be enabled when UEFI Secure Boot is disabled. One of lockdown's features is to prevent kexec from loading untrusted kernels. Lockdown can be enabled through a bootparam or after the kernel has booted through securityfs. If IMA appraisal is used with the "ima_appraise=log" boot param, lockdown can be defeated with kexec on any machine when Secure Boot is disabled or unavailable. IMA prevents setting "ima_appraise=log" from the boot param when Secure Boot is enabled, but this does not cover cases where lockdown is used without Secure Boot. To defeat lockdown, boot without Secure Boot and add ima_appraise=log to the kernel command line; then: $ echo "integrity" > /sys/kernel/security/lockdown $ echo "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig" > \ /sys/kernel/security/ima/policy $ kexec -ls unsigned-kernel Add a call to verify ima appraisal is set to "enforce" whenever lockdown is enabled. This fixes CVE-2022-21505. Cc: stable@vger.kernel.org Fixes: 29d3c1c8dfe7 ("kexec: Allow kexec_file() with appropriate IMA policy when locked down") Signed-off-by: Eric Snowberg Acked-by: Mimi Zohar Reviewed-by: John Haxby Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ima: Do not print policy rule with inactive LSM labels

2022-02-16T11:52:47Z

commit 89677197ae709eb1ab3646952c44f6a171c9e74c upstream. Before printing a policy rule scan for inactive LSM labels in the policy rule. Inactive LSM labels are identified by args_p != NULL and rule == NULL. Fixes: 483ec26eed42 ("ima: ima/lsm policy rule loading logic bug fixes") Signed-off-by: Stefan Berger Cc: # v5.6+ Acked-by: Christian Brauner [zohar@linux.ibm.com: Updated "Fixes" tag] Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

ima: Have the LSM free its audit rule

2020-08-19T06:16:12Z

[ Upstream commit 9ff8a616dfab96a4fa0ddd36190907dc68886d9b ] Ask the LSM to free its audit rule rather than directly calling kfree(). Both AppArmor and SELinux do additional work in their audit_rule_free() hooks. Fix memory leaks by allowing the LSMs to perform necessary work. Fixes: b16942455193 ("ima: use the lsm policy update notifier") Signed-off-by: Tyler Hicks Cc: Janne Karhunen Cc: Casey Schaufler Reviewed-by: Mimi Zohar Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Set again build_ima_appraise variable

2020-06-22T07:31:17Z

[ Upstream commit b59fda449cf07f2db3be3a67142e6c000f5e8d79 ] After adding the new add_rule() function in commit c52657d93b05 ("ima: refactor ima_init_policy()"), all appraisal flags are added to the temp_ima_appraise variable. Revert to the previous behavior instead of removing build_ima_appraise, to benefit from the protection offered by __ro_after_init. The mentioned commit introduced a bug, as it makes all the flags modifiable, while build_ima_appraise flags can be protected with __ro_after_init. Cc: stable@vger.kernel.org # 5.0.x Fixes: c52657d93b05 ("ima: refactor ima_init_policy()") Co-developed-by: Roberto Sassu Signed-off-by: Roberto Sassu Signed-off-by: Krzysztof Struczynski Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Remove redundant policy rule set in add_rules()

2020-06-22T07:31:17Z

[ Upstream commit 6ee28442a465ab4c4be45e3b15015af24b1ba906 ] Function ima_appraise_flag() returns the flag to be set in temp_ima_appraise depending on the hook identifier passed as an argument. It is not necessary to set the flag again for the POLICY_CHECK hook. Signed-off-by: Krzysztof Struczynski Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Directly assign the ima_default_policy pointer to ima_rules

2020-06-22T07:31:15Z

commit 067a436b1b0aafa593344fddd711a755a58afb3b upstream. This patch prevents the following oops: [ 10.771813] BUG: kernel NULL pointer dereference, address: 0000000000000 [...] [ 10.779790] RIP: 0010:ima_match_policy+0xf7/0xb80 [...] [ 10.798576] Call Trace: [ 10.798993] ? ima_lsm_policy_change+0x2b0/0x2b0 [ 10.799753] ? inode_init_owner+0x1a0/0x1a0 [ 10.800484] ? _raw_spin_lock+0x7a/0xd0 [ 10.801592] ima_must_appraise.part.0+0xb6/0xf0 [ 10.802313] ? ima_fix_xattr.isra.0+0xd0/0xd0 [ 10.803167] ima_must_appraise+0x4f/0x70 [ 10.804004] ima_post_path_mknod+0x2e/0x80 [ 10.804800] do_mknodat+0x396/0x3c0 It occurs when there is a failure during IMA initialization, and ima_init_policy() is not called. IMA hooks still call ima_match_policy() but ima_rules is NULL. This patch prevents the crash by directly assigning the ima_default_policy pointer to ima_rules when ima_rules is defined. This wouldn't alter the existing behavior, as ima_rules is always set at the end of ima_init_policy(). Cc: stable@vger.kernel.org # 3.7.x Fixes: 07f6a79415d7d ("ima: add appraise action keywords and default rules") Reported-by: Takashi Iwai Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman