From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
[ Upstream commit 55be873695ed8912eb77ff46d1d1cadf028bd0f3 ]
While reading sysctl_tcp_notsent_lowat, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/net/tcp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 96dae0937998..eb984ec22f22 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1947,7 +1947,7 @@ void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr);
static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp)
{
struct net *net = sock_net((struct sock *)tp);
- return tp->notsent_lowat ?: net->ipv4.sysctl_tcp_notsent_lowat;
+ return tp->notsent_lowat ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat);
}
/* @wake is one when sk_stream_write_space() calls us.
--
2.35.1
