CVEvulnerability
CVE-2026-98026
- Status
- Received
- Published
- 2026-09-25
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: mcast: properly convert mglist to rcu
Sashiko reported a bug [1] that br_multicast_del_port_group unlists the
port group not using proper rcu helper that preserves the next pointer and
after that immediately frees the port group without waiting for rcu grace
period. The only rcu walker of mglist is br_multicast_list_adjacent() and
it turns out that function has always been buggy because mglist was never
properly converted to RCU. Fix it by converting it to rcu and moving its
initialization after eth_addr's. Initializing p->next can use
RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call
later, besides we're initializing an unpublished structure anyway.
[1] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260826014200.362304-1-littleddfu%40gmail.com
References
- https://git.kernel.org/stable/c/37cb9a81600da8250f24e25edc07253b62353cbe git.kernel.org
- https://git.kernel.org/stable/c/38ab2a435001a3c4dbeb70a52f5921e1ccd66f55 git.kernel.org
- https://git.kernel.org/stable/c/4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0 git.kernel.org
- https://git.kernel.org/stable/c/98247c8264d2076f81fa114bdfa2c2271953ac7c git.kernel.org
- https://git.kernel.org/stable/c/f7bf57e94a5d6214b87be08486cb33836fbfa573 git.kernel.org