p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

udp: fix GRO reception in case of length mismatch 

Currently, the UDP GRO code path does bad things on some edge
conditions - Aggregation can happen even on packet with different
lengths.

Fix the above by rewriting the 'complete' condition for GRO
packets. While at it, note explicitly that we allow merging the
first packet per burst below gso_size.

Reported-by: Sean Tong <seantong114@gmail.com>
Fixes: e20cf8d3f1 ("udp: implement GRO for plain UDP sockets.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2019-04-26 12:50:44 +02:00 committed by David S. Miller
parent fbef9478ff
commit 21f1b8a663
1 changed files with 5 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
net/ipv4/udp_offload.c
View File

@ -377,13 +377,14 @@ static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
/* 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 execessive truesize values
* leading to execessive truesize values.
* On len mismatch merge the first packet shorter than gso_size,
* otherwise complete the GRO packet.
*/
if (!skb_gro_receive(p, skb) &&
if (uh->len > uh2->len || skb_gro_receive(p, skb) ||
uh->len != uh2->len ||
NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX)
pp = p;
else if (uh->len != uh2->len)
pp = p;
return pp;
}