| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 13/37] tcp: Fix a data-race around sysctl_tcp_notsent_lowat. | Date | Wed, 27 Jul 2022 18:10:39 +0200 |
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From: Kuniyuki Iwashima <kuniyu@amazon.com>
[ 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@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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 181db7dab176..5e719f9d60fd 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1882,7 +1882,7 @@ 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); } static inline bool tcp_stream_memory_free(const struct sock *sk) -- 2.35.1
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