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 Assisted-by: LLM Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> --- net/ipv6/route.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 153ce16628c1e1..a5e955e56e794f 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6509,8 +6509,6 @@ void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0, 0, 0, RT_DEL_REASON_UNSPEC); if (err < 0) { - /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ - WARN_ON(err == -EMSGSIZE); kfree_skb(skb); goto errout; } -- 2.55.0