Bug 2517054 (CVE-2026-74512)

Summary: CVE-2026-74512 kernel: audit: fix potential use-after-free in audit_del_rule()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. During the deletion of audit rules, the `audit_del_rule()` function prematurely frees a resource while other kernel functions can still access it. This creates a use-after-free vulnerability, which a local attacker could potentially exploit to cause system instability, information disclosure, or potentially escalate privileges.
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Description OSIDB Bzimport 2026-08-15 12:47:15 UTC 
In the Linux kernel, the following vulnerability has been resolved:

audit: fix potential use-after-free in audit_del_rule()

`audit_del_rule()` destroys `e->rule.exe` via `audit_remove_mark_rule()`
before unlinking the rule from RCU-visible filter lists and waiting for a
grace period. Concurrent readers in `audit_filter()` and
`audit_filter_rules()` still dereference `e->rule.exe`, while the fsnotify
mark can be freed on an independent lifetime path. This creates a
use-after-free window during rule deletion.

Fix this by unlinking the rule from the RCU-visible lists and invoking
`synchronize_rcu()` before calling `audit_remove_mark_rule()` (and other
rule removal helpers). This ensures that all existing RCU readers have
exited the critical section before any underlying resources are destroyed.
Comment 1 Mauro Matteo Cascella 2026-08-19 17:56:37 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081543-CVE-2026-74512-3449@gregkh/T