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use RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call later, besides we're initializing an unpublished structure anyway.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
https://git.kernel.org/stable/c/f7bf57e94a5d6214b87be08486cb33836fbfa573
https://git.kernel.org/stable/c/98247c8264d2076f81fa114bdfa2c2271953ac7c
https://git.kernel.org/stable/c/4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0
https://git.kernel.org/stable/c/38ab2a435001a3c4dbeb70a52f5921e1ccd66f55