af_unix: Annotate data-race of sk->sk_shutdown in sk_diag_fill().

[ Upstream commit efaf24e30ec39ebbea9112227485805a48b0ceb1 ]

While dumping sockets via UNIX_DIAG, we do not hold unix_state_lock().

Let's use READ_ONCE() to read sk->sk_shutdown.

Fixes: e4e541a84863 ("sock-diag: Report shutdown for inet and unix sockets (v2)")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/unix/diag.c b/net/unix/diag.c
index 5bc5cb83cc6e4defbaa461bb9aab282d9d9df473..7066a362341062f832d11ec285bba77a92171c12 100644 (file)
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -164,7 +164,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
            sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
                goto out_nlmsg_trim;
 
-       if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
+       if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, READ_ONCE(sk->sk_shutdown)))
                goto out_nlmsg_trim;
 
        if ((req->udiag_show & UDIAG_SHOW_UID) &&