| Message ID | BWGqSgvElVUWVBHlyAGeResnioScs0ES23kwzp1JHo@cp4-web-028.plabs.ch |
|---|---|
| State | Superseded |
| Headers | show |
| Series | net: udp: fix Fast/frag0 UDP GRO | expand |
On Wed, Nov 11, 2020 at 3:45 PM Alexander Lobakin <alobakin@pm.me> wrote: > > 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@google.com> > Cc: Jakub Kicinski <kuba@kernel.org> > Cc: Willem de Bruijn <willemb@google.com> > Signed-off-by: Alexander Lobakin <alobakin@pm.me> Acked-by: Willem de Bruijn <willemb@google.com>
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index e67a66fbf27b..13740e9fe6ec 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -366,7 +366,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 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;
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@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexander Lobakin <alobakin@pm.me> --- net/ipv4/udp_offload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)