Commit 1a63cb91 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

tcp: Fix a data-race around sysctl_tcp_retrans_collapse. 



While reading sysctl_tcp_retrans_collapse, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its reader.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4845b571

net/ipv4/tcp_output.c

+1 −1
Original line number Diff line number Diff line
@@ -3105,7 +3105,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, 
	struct sk_buff *skb = to, *tmp;

	bool first = true;



	if (!sock_net(sk)->ipv4.sysctl_tcp_retrans_collapse)

	if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retrans_collapse))

		return;

	if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)

		return;