This is a note to let you know that I've just added the patch titled net: annotate sk->sk_err write from do_recvmmsg() to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-annotate-sk-sk_err-write-from-do_recvmmsg.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 89cbd7e6bd310caafcc1f4133879873282c4b7b0 Author: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Tue May 9 16:35:53 2023 +0000 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 <edumazet@xxxxxxxxxx> Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/socket.c b/net/socket.c index 7bcd7053e61f2..e59b114e16ba7 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2383,7 +2383,7 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, * 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);