This is a note to let you know that I've just added the patch titled
net: skip virtio_net_hdr_set_proto if protocol already set
to the 5.15-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-skip-virtio_net_hdr_set_proto-if-protocol-alread.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2c0bdb17dca4f54825a4037a2d722c088755ebee
Author: Willem de Bruijn <willemb@xxxxxxxxxx>
Date: Mon Dec 20 09:50:27 2021 -0500
net: skip virtio_net_hdr_set_proto if protocol already set
[ Upstream commit 1ed1d592113959f00cc552c3b9f47ca2d157768f ]
virtio_net_hdr_set_proto infers skb->protocol from the virtio_net_hdr
gso_type, to avoid packets getting dropped for lack of a proto type.
Its protocol choice is a guess, especially in the case of UFO, where
the single VIRTIO_NET_HDR_GSO_UDP label covers both UFOv4 and UFOv6.
Skip this best effort if the field is already initialized. Whether
explicitly from userspace, or implicitly based on an earlier call to
dev_parse_header_protocol (which is more robust, but was introduced
after this patch).
Fixes: 9d2f67e43b73 ("net/packet: fix packet drop as of virtio gso")
Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211220145027.2784293-1-willemdebruijn.kernel@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 22dd48c825600..a960de68ac69e 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -25,6 +25,9 @@ static inline bool virtio_net_hdr_match_proto(__be16 protocol, __u8 gso_type)
static inline int virtio_net_hdr_set_proto(struct sk_buff *skb,
const struct virtio_net_hdr *hdr)
{
+ if (skb->protocol)
+ return 0;
+
switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
case VIRTIO_NET_HDR_GSO_UDP:
