Messages in this thread Patch in this message | | | Subject | [PATCH] tcp: fix retransmit of partially acked frames | From | Eric Dumazet <> | Date | Wed, 18 Apr 2012 22:14:23 +0200 |
| |
From: Eric Dumazet <edumazet@google.com>
Alexander Beregalov reported skb_over_panic errors and provided stack trace.
I occurs commit a21d45726aca (tcp: avoid order-1 allocations on wifi and tx path) added a regression, when a retransmit is done after a partial ACK.
tcp_retransmit_skb() tries to aggregate several frames if the first one has enough available room to hold the following ones payload. This is controlled by /proc/sys/net/ipv4/tcp_retrans_collapse tunable (default : enabled)
Problem is we must make sure _pskb_trim_head() doesnt fool skb_availroom() when pulling some bytes from skb (this pull is done when receiver ACK part of the frame).
Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Cc: Marc MERLIN <marc@merlins.org> Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/ipv4/tcp_output.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 376b2cf..7ac6423 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1096,6 +1096,7 @@ static void __pskb_trim_head(struct sk_buff *skb, int len) eat = min_t(int, len, skb_headlen(skb)); if (eat) { __skb_pull(skb, eat); + skb->avail_size -= eat; len -= eat; if (!len) return;
| |