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 5.4-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-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 19ff7ee77b98d1294051f9a2a3a7ba96963951fe
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 02feaf5bd84a3..9dd4c7ce8343a 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2723,7 +2723,7 @@ 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);
