This is a note to let you know that I've just added the patch titled
af_unix: Fix data race around sk->sk_err.
to the 4.19-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:
af_unix-fix-data-race-around-sk-sk_err.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 21ad5ec6fa8e0a999a6b1b649d59a1810705a1c6
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Fri Sep 1 17:27:08 2023 -0700
af_unix: Fix data race around sk->sk_err.
[ Upstream commit b192812905e4b134f7b7994b079eb647e9d2d37e ]
As with sk->sk_shutdown shown in the previous patch, sk->sk_err can be
read locklessly by unix_dgram_sendmsg().
Let's use READ_ONCE() for sk_err as well.
Note that the writer side is marked by commit cc04410af7de ("af_unix:
annotate lockless accesses to sk->sk_err").
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/sock.c b/net/core/sock.c
index 9a4559b863fb7..e1d0c8c715b87 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2074,7 +2074,7 @@ static long sock_wait_for_wmem(struct sock *sk, long timeo)
break;
if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
break;
- if (sk->sk_err)
+ if (READ_ONCE(sk->sk_err))
break;
timeo = schedule_timeout(timeo);
}
