From: Eric Dumazet Date: Fri, 28 Jul 2023 15:03:09 +0000 (+0000) Subject: net: annotate data-race around sk->sk_txrehash X-Git-Tag: v6.6.7~2249^2~29^2~9 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c76a0328899bbe226f8adeb88b8da9e4167bd316;p=platform%2Fkernel%2Flinux-starfive.git net: annotate data-race around sk->sk_txrehash sk_getsockopt() runs locklessly. This means sk->sk_txrehash can be read while other threads are changing its value. Other locations were handled in commit cb6cd2cec799 ("tcp: Change SYN ACK retransmit behaviour to account for rehash") Fixes: 26859240e4ee ("txhash: Add socket option to control TX hash rethink behavior") Signed-off-by: Eric Dumazet Cc: Akhmat Karakotov Signed-off-by: David S. Miller --- diff --git a/net/core/sock.c b/net/core/sock.c index bd201d1..adec93d 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1534,7 +1534,9 @@ set_sndbuf: } if ((u8)val == SOCK_TXREHASH_DEFAULT) val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash); - /* Paired with READ_ONCE() in tcp_rtx_synack() */ + /* Paired with READ_ONCE() in tcp_rtx_synack() + * and sk_getsockopt(). + */ WRITE_ONCE(sk->sk_txrehash, (u8)val); break; @@ -1978,7 +1980,8 @@ int sk_getsockopt(struct sock *sk, int level, int optname, break; case SO_TXREHASH: - v.val = sk->sk_txrehash; + /* Paired with WRITE_ONCE() in sk_setsockopt() */ + v.val = READ_ONCE(sk->sk_txrehash); break; default: