Patchwork : tcp: Fix order of tests in tcp_retransmit_skb()

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Submitter David Miller
Date Sept. 23, 2008, 8:34 a.m.
Message ID <20080923.013406.65754438.davem@davemloft.net>
Download mbox | patch
Permalink /patch/1033/
State Accepted
Delegated to: David Miller
Headers show

Comments

David Miller - Sept. 23, 2008, 8:34 a.m.
The assertion I placed in skb_queue_next() found a bug already,
but this specific case turned out to be harmless :-)

tcp: Fix order of tests in tcp_retransmit_skb()

tcp_write_queue_next() must only be made if we know that
tcp_skb_is_last() evaluates to false.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/tcp_output.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Patch

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index c3d58ee..a8499ef 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1932,8 +1932,8 @@  int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	/* Collapse two adjacent packets if worthwhile and we can. */
 	if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) &&
 	    (skb->len < (cur_mss >> 1)) &&
-	    (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) &&
 	    (!tcp_skb_is_last(sk, skb)) &&
+	    (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) &&
 	    (skb_shinfo(skb)->nr_frags == 0 &&
 	     skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) &&
 	    (tcp_skb_pcount(skb) == 1 &&