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.
References
- https://git.kernel.org/stable/c/246df90b5f1a8a6e6abbd2f058b029558720adec
- https://git.kernel.org/stable/c/45bf3df5b32e5a49953e7ceabc55f7dd85380e46
- https://git.kernel.org/stable/c/5b8f46864f06d6dbacb7dcea52bc084dfd122638
- https://git.kernel.org/stable/c/78bde7e9bd36eaae1b8e8cfcd47f12a34f301dbf
- https://git.kernel.org/stable/c/cae0dfed5d307b240bff71c3cf206652d1b6f215