From: Willem de Bruijn willemb@google.com

commit dd89a81d850fa9a65f67b4527c0e420d15bf836c upstream.

Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is not known or does not have a GRO handler.

Such a packet is easily constructed. Syzbot generates them and sets off this warning.

Remove the warning as it is expected and not actionable.

The warning was previously reduced from WARN_ON to WARN_ON_ONCE in commit 270136613bf7 ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad proto callbacks").

Signed-off-by: Willem de Bruijn willemb@google.com Reviewed-by: Eric Dumazet edumazet@google.com Link: https://lore.kernel.org/r/20240614122552.1649044-1-willemdebruijn.kernel@gma... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Denis Arefev arefev@swemel.ru --- Backport fix for CVE-2024-44940 Link: https://www.cve.org/CVERecord/?id=CVE-2024-44940 --- net/ipv4/fou.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index 1d67df4d8ed6..b1a8e4eec3f6 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -453,7 +453,7 @@ static struct sk_buff *gue_gro_receive(struct sock *sk,

offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[proto]); - if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive)) + if (!ops || !ops->callbacks.gro_receive) goto out;

pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);