[PATCHv2 1/2] phonet: take correct lock to peek at the RX queue

["Rémi Denis-Courmont" <remi@remlab.net>]

From: Rémi Denis-Courmont <courmisch@gmail.com>

The receive queue is protected by its embedded spin-lock, not the
socket lock, so we need the former lock here (and only that one).

Fixes: 107d0d9b8d9a ("Phonet: Phonet datagram transport protocol")
Reported-by: Luosili <rootlab@huawei.com>
Signed-off-by: Rémi Denis-Courmont <courmisch@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
---
 net/phonet/datagram.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/phonet/datagram.c b/net/phonet/datagram.c
index 3aa50dc7535b..976fe250b509 100644
--- a/net/phonet/datagram.c
+++ b/net/phonet/datagram.c
@@ -34,10 +34,10 @@ static int pn_ioctl(struct sock *sk, int cmd, int *karg)
 
 	switch (cmd) {
 	case SIOCINQ:
-		lock_sock(sk);
+		spin_lock_bh(&sk->sk_receive_queue.lock);
 		skb = skb_peek(&sk->sk_receive_queue);
 		*karg = skb ? skb->len : 0;
-		release_sock(sk);
+		spin_unlock_bh(&sk->sk_receive_queue.lock);
 		return 0;
 
 	case SIOCPNADDRESOURCE:
-- 
2.43.0