This is a note to let you know that I've just added the patch titled
net: gro: add flush check in udp_gro_receive_segment
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-gro-add-flush-check-in-udp_gro_receive_segment.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 ba1fcd59b1bc712a623c6ee2684f50fc81ca0d74
Author: Richard Gobert <richardbgobert@xxxxxxxxx>
Date: Tue Apr 30 16:35:55 2024 +0200
net: gro: add flush check in udp_gro_receive_segment
[ Upstream commit 5babae777c61aa8a8679d59d3cdc54165ad96d42 ]
GRO-GSO path is supposed to be transparent and as such L3 flush checks are
relevant to all UDP flows merging in GRO. This patch uses the same logic
and code from tcp_gro_receive, terminating merge if flush is non zero.
Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.")
Signed-off-by: Richard Gobert <richardbgobert@xxxxxxxxx>
Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 889d4926fc0c1..e5971890d637d 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -471,6 +471,7 @@ static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
struct sk_buff *p;
unsigned int ulen;
int ret = 0;
+ int flush;
/* requires non zero csum, for symmetry with GSO */
if (!uh->check) {
@@ -504,13 +505,22 @@ static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
return p;
}
+ flush = NAPI_GRO_CB(p)->flush;
+
+ if (NAPI_GRO_CB(p)->flush_id != 1 ||
+ NAPI_GRO_CB(p)->count != 1 ||
+ !NAPI_GRO_CB(p)->is_atomic)
+ flush |= NAPI_GRO_CB(p)->flush_id;
+ else
+ NAPI_GRO_CB(p)->is_atomic = false;
+
/* Terminate the flow on len mismatch or if it grow "too much".
* Under small packet flood GRO count could elsewhere grow a lot
* leading to excessive truesize values.
* On len mismatch merge the first packet shorter than gso_size,
* otherwise complete the GRO packet.
*/
- if (ulen > ntohs(uh2->len)) {
+ if (ulen > ntohs(uh2->len) || flush) {
pp = p;
} else {
if (NAPI_GRO_CB(skb)->is_flist) {
