This is a note to let you know that I've just added the patch titled
net: udp: fix UDP header access on Fast/frag0 UDP GRO
to the 5.9-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-udp-fix-udp-header-access-on-fast-frag0-udp-gro.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Nov 16 07:48:29 PM CET 2020
From: Alexander Lobakin <alobakin@xxxxx>
Date: Wed, 11 Nov 2020 20:45:25 +0000
Subject: net: udp: fix UDP header access on Fast/frag0 UDP GRO
From: Alexander Lobakin <alobakin@xxxxx>
[ Upstream commit 4b1a86281cc1d0de46df3ad2cb8c1f86ac07681c ]
UDP GRO uses udp_hdr(skb) in its .gro_receive() callback. While it's
probably OK for non-frag0 paths (when all headers or even the entire
frame are already in skb head), this inline points to junk when
using Fast GRO (napi_gro_frags() or napi_gro_receive() with only
Ethernet header in skb head and all the rest in the frags) and breaks
GRO packet compilation and the packet flow itself.
To support both modes, skb_gro_header_fast() + skb_gro_header_slow()
are typically used. UDP even has an inline helper that makes use of
them, udp_gro_udphdr(). Use that instead of troublemaking udp_hdr()
to get rid of the out-of-order delivers.
Present since the introduction of plain UDP GRO in 5.0-rc1.
Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.")
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Alexander Lobakin <alobakin@xxxxx>
Acked-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/udp_offload.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -366,7 +366,7 @@ out:
static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
struct sk_buff *skb)
{
- struct udphdr *uh = udp_hdr(skb);
+ struct udphdr *uh = udp_gro_udphdr(skb);
struct sk_buff *pp = NULL;
struct udphdr *uh2;
struct sk_buff *p;
Patches currently in stable-queue which might be from alobakin@xxxxx are
queue-5.9/net-udp-fix-udp-header-access-on-fast-frag0-udp-gro.patch
queue-5.9/virtio-virtio_console-fix-dma-memory-allocation-for-rproc-serial.patch
queue-5.9/ethtool-netlink-add-missing-netdev_features_change-call.patch
queue-5.9/net-udp-fix-ip-header-access-and-skb-lookup-on-fast-frag0-udp-gro.patch
