From 24ab059d2ebd62fdccc43794796f6ffbabe49ebc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 19 Dec 2023 12:53:31 +0000 Subject: [PATCH] net: check dev->gso_max_size in gso_features_check() Some drivers might misbehave if TSO packets get too big. GVE for instance uses a 16bit field in its TX descriptor, and will do bad things if a packet is bigger than 2^16 bytes. Linux TCP stack honors dev->gso_max_size, but there are other ways for too big packets to reach an ndo_start_xmit() handler : virtio_net, af_packet, GRO... Add a generic check in gso_features_check() and fallback to GSO when needed. gso_max_size was added in the blamed commit. Fixes: 82cc1a7a5687 ("[NET]: Add per-connection option to set max TSO frame size") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20231219125331.4127498-1-edumazet@google.com Signed-off-by: Paolo Abeni --- net/core/dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index c879246be48d..ad20bebe153f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3472,6 +3472,9 @@ static netdev_features_t gso_features_check(const struct sk_buff *skb, if (gso_segs > READ_ONCE(dev->gso_max_segs)) return features & ~NETIF_F_GSO_MASK; + if (unlikely(skb->len >= READ_ONCE(dev->gso_max_size))) + return features & ~NETIF_F_GSO_MASK; + if (!skb_shinfo(skb)->gso_type) { skb_warn_bad_offload(skb); return features & ~NETIF_F_GSO_MASK;