net: check dev->gso_max_size in gso_features_check()

[ 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: 82cc1a7 ("[NET]: Add per-connection option to set max TSO frame size") Signed-off-by: Eric Dumazet <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Abeni <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
raystef66 · Jan 9, 2024 · 98e4ae5 · 98e4ae5
1 parent 5de5f76
commit 98e4ae5
Showing 1 changed file with 3 additions and 0 deletions.
diff --git 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;