| Message ID | 1433521014-2465771-1-git-send-email-kafai@fb.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index a369e8a..6c95c28 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1984,8 +1984,9 @@ static int tcp_mtu_probe(struct sock *sk) skb->len, 0); } else { __pskb_trim_head(skb, copy); - tcp_set_skb_tso_segs(sk, skb, mss_now); } + tcp_set_skb_tso_segs(sk, skb, mss_now); + TCP_SKB_CB(skb)->seq += copy; }
The problem is caught by this WARN_ON(len > skb->len) in tcp_fragment(): [<ffffffff810510ca>] warn_slowpath_null+0x1a/0x20 [<ffffffff8160ec90>] tcp_fragment+0x2a0/0x2b0 [<ffffffff81604e06>] tcp_mark_head_lost+0x196/0x230 [<ffffffff8160585d>] tcp_update_scoreboard+0x4d/0x80 [<ffffffff8160a9ac>] tcp_fastretrans_alert+0x6ac/0xa90 [<ffffffff8160b834>] tcp_ack+0x9d4/0x10e0 [<ffffffff8160c699>] tcp_rcv_established+0x309/0x7e0 The WARN_ON pointed out that tcp_skb_pcount (i.e. TCP_SKB_CB(skb)->tcp_gso_segs) and skb->len is inconsistent. The WARN_ON stack goes away after setting net.ipv4.tcp_mtu_probing to 0. This patch is to set the pcount after skb_pull() was called in tcp_mtu_probe(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Reported-by: Grant Zhang <gzhang@fastly.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> --- net/ipv4/tcp_output.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)