What happened
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state sashiko reports: "nfnl_log_net_exit() calls nf_log_unset(), which clears the logger pointer without an RCU grace period. Immediately after, ops_free_list() frees the per-net state while concurrent packets might still be executing nf_log_packet() under rcu_read_lock()." Clear the pointer via .pre_exit to make sure rcu readers have completed before pernet storage is free'd. The change in nf_log_syslog.c is only done for consistency: it doesn't use pernet data.
Affected versions
Linux: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 through before f4461654374576e9d5d0245fd534c46ad8509051 (git); 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 through before dc20050b6b12ca58066715d088e1a537535d938d (git); 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 through before 33d1469b0124cc0baaea7a2032123b77a81e0940 (git); before 6.12.111 (semver); before 6.18.53 (semver) Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.