From bd0f360ee86494037fbffcac28dbb47c438b33df Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 9 May 2023 16:35:53 +0000 Subject: [PATCH] net: annotate sk->sk_err write from do_recvmmsg() [ Upstream commit e05a5f510f26607616fecdd4ac136310c8bea56b ] do_recvmmsg() can write to sk->sk_err from multiple threads. As said before, many other points reading or writing sk_err need annotations. Fixes: 34b88a68f26a ("net: Fix use after free in the recvmmsg exit path") Signed-off-by: Eric Dumazet Reported-by: syzbot Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/socket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/socket.c b/net/socket.c index 577079a..c2e0a22 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2890,7 +2890,7 @@ static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg, * error to return on the next call or if the * app asks about it using getsockopt(SO_ERROR). */ - sock->sk->sk_err = -err; + WRITE_ONCE(sock->sk->sk_err, -err); } out_put: fput_light(sock->file, fput_needed); -- 2.7.4