From 561022acb1ce62e50f7a8258687a21b84282a4cb Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 2 Jul 2021 13:09:03 -0700 Subject: tcp: annotate data races around tp->mtu_info While tp->mtu_info is read while socket is owned, the write sides happen from err handlers (tcp_v[46]_mtu_reduced) which only own the socket spinlock. Fixes: 563d34d05786 ("tcp: dont drop MTU reduction indications") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index e66ad6bfe808..b9dc2d6197be 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -342,7 +342,7 @@ void tcp_v4_mtu_reduced(struct sock *sk) if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) return; - mtu = tcp_sk(sk)->mtu_info; + mtu = READ_ONCE(tcp_sk(sk)->mtu_info); dst = inet_csk_update_pmtu(sk, mtu); if (!dst) return; @@ -546,7 +546,7 @@ int tcp_v4_err(struct sk_buff *skb, u32 info) if (sk->sk_state == TCP_LISTEN) goto out; - tp->mtu_info = info; + WRITE_ONCE(tp->mtu_info, info); if (!sock_owned_by_user(sk)) { tcp_v4_mtu_reduced(sk); } else { -- cgit v1.2.3-58-ga151