net: gro: add flush check in udp_gro_receive_segment

[ Upstream commit 5babae777c ]

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: e20cf8d3f1 ("udp: implement GRO for plain UDP sockets.")
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Richard Gobert 2024-04-30 16:35:55 +02:00 committed by Greg Kroah-Hartman
parent dbd9466d32
commit ee190d04c2

View file

@ -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) {