This is a note to let you know that I've just added the patch titled
net: Fix gso_features_check to check for both dev->gso_{ipv4_,}max_size
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-fix-gso_features_check-to-check-for-both-dev-gso.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b3f1a4ba04b75a4f771dcfaeea377d83aba3c290
Author: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Date: Mon Sep 23 23:22:42 2024 +0200
net: Fix gso_features_check to check for both dev->gso_{ipv4_,}max_size
[ Upstream commit e609c959a939660c7519895f853dfa5624c6827a ]
Commit 24ab059d2ebd ("net: check dev->gso_max_size in gso_features_check()")
added a dev->gso_max_size test to gso_features_check() in order to fall
back to GSO when needed.
This was added as it was noticed that some drivers could misbehave if TSO
packets get too big. However, the check doesn't respect dev->gso_ipv4_max_size
limit. For instance, a device could be configured with BIG TCP for IPv4,
but not IPv6.
Therefore, add a netif_get_gso_max_size() equivalent to netif_get_gro_max_size()
and use the helper to respect both limits before falling back to GSO engine.
Fixes: 24ab059d2ebd ("net: check dev->gso_max_size in gso_features_check()")
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://patch.msgid.link/20240923212242.15669-2-daniel@xxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e4f02e638b9d9..8f5ac20b4c03d 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -5038,6 +5038,15 @@ netif_get_gro_max_size(const struct net_device *dev, const struct sk_buff *skb)
READ_ONCE(dev->gro_ipv4_max_size);
}
+static inline unsigned int
+netif_get_gso_max_size(const struct net_device *dev, const struct sk_buff *skb)
+{
+ /* pairs with WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
+ return skb->protocol == htons(ETH_P_IPV6) ?
+ READ_ONCE(dev->gso_max_size) :
+ READ_ONCE(dev->gso_ipv4_max_size);
+}
+
static inline bool netif_is_macsec(const struct net_device *dev)
{
return dev->priv_flags & IFF_MACSEC;
diff --git a/net/core/dev.c b/net/core/dev.c
index 5a5bd339f11eb..decfa7cbba50a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3500,7 +3500,7 @@ 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)))
+ if (unlikely(skb->len >= netif_get_gso_max_size(dev, skb)))
return features & ~NETIF_F_GSO_MASK;
if (!skb_shinfo(skb)->gso_type) {
