From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
[ Upstream commit 1a63cb91f0c2fcdeced6d6edee8d1d886583d139 ]
While reading sysctl_tcp_retrans_collapse, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/tcp_output.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 5bcd12a9d8ff..3554a4c1e1b8 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3103,7 +3103,7 @@ 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;
--
2.35.1
