| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.13 155/156] udp: properly flush normal packet at GRO time | Date | Thu, 22 Jul 2021 18:32:10 +0200 |
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From: Paolo Abeni <pabeni@redhat.com>
commit b43c8909be52f2baca8884f967b418a88424494a upstream.
If an UDP packet enters the GRO engine but is not eligible for aggregation and is not targeting an UDP tunnel, udp_gro_receive() will not set the flush bit, and packet could delayed till the next napi flush.
Fix the issue ensuring non GROed packets traverse skb_gro_flush_final().
Reported-and-tested-by: Matthias Treydte <mt@waldheinz.de> Fixes: 18f25dc39990 ("udp: skip L4 aggregation for UDP tunnel packets") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv4/udp_offload.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -525,8 +525,10 @@ struct sk_buff *udp_gro_receive(struct l if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) - pp = call_gro_receive(udp_gro_receive_segment, head, skb); - return pp; + return call_gro_receive(udp_gro_receive_segment, head, skb); + + /* no GRO, be sure flush the current packet */ + goto out; } if (NAPI_GRO_CB(skb)->encap_mark ||
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