6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daehyeon Ko <4ncienth@gmail.com> commit c97426ec649d99596d8969e1a052c16b14b7b485 upstream. fib6_info_hw_flags_set() sizes the skb with rt6_nlmsg_size() and later fills it with rt6_fill_node(). With nexthop compatibility mode enabled, a concurrent replacement can grow the group between these independent snapshots. rt6_fill_node() can then legitimately return -EMSGSIZE, so the warning does not prove a sizing bug. Remove the warning. The existing error path still frees the skb and reports the error to listeners. Fixes: 907eea486888 ("net: ipv6: Emit notification when fib hardware flags are changed") Reported-by: Ido Schimmel Link: https://lore.kernel.org/netdev/20261007114003.GA1011260@shredder/ Suggested-by: Ido Schimmel Cc: stable@vger.kernel.org Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Link: https://patch.msgid.link/4012604727e5ba80b69ccd4d08796511397ddaef.1791423190.git.4ncienth@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/ipv6/route.c | 2 -- 1 file changed, 2 deletions(-) --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6340,8 +6340,6 @@ void fib6_info_hw_flags_set(struct net * err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0, 0, 0); if (err < 0) { - /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ - WARN_ON(err == -EMSGSIZE); kfree_skb(skb); goto errout; }