4.19-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 24ab059d2ebd62fdccc43794796f6ffbabe49ebc ]
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 edumazet@google.com Link: https://lore.kernel.org/r/20231219125331.4127498-1-edumazet@google.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/dev.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/core/dev.c b/net/core/dev.c index ea05db68aa95a..b5c9648c2192f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3200,6 +3200,9 @@ static netdev_features_t gso_features_check(const struct sk_buff *skb, if (gso_segs > 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;