af_unix: Fix wrong ioctl(SIOCATMARK) when consumed OOB skb is at the …

…head. [ Upstream commit e400cfa ] Even if OOB data is recv()ed, ioctl(SIOCATMARK) must return 1 when the OOB skb is at the head of the receive queue and no new OOB data is queued. Without fix: # RUN msg_oob.no_peek.oob ... # msg_oob.c:305:oob:Expected answ[0] (0) == oob_head (1) # oob: Test terminated by assertion # FAIL msg_oob.no_peek.oob not ok 2 msg_oob.no_peek.oob With fix: # RUN msg_oob.no_peek.oob ... # OK msg_oob.no_peek.oob ok 2 msg_oob.no_peek.oob Fixes: 314001f ("af_unix: Add OOB support") Signed-off-by: Kuniyuki Iwashima <[email protected]> Signed-off-by: Paolo Abeni <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
pop-os · mmstick · Jun 2, 2024 · Jun 17, 2024 · Jun 27, 2024 · Mar 27, 2024
commit 09a325ac1d820aa49082e963acb188292e0b2252
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
@@ -3154,12 +3154,23 @@ static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 #if IS_ENABLED(CONFIG_AF_UNIX_OOB)
 	case SIOCATMARK:
 		{
+			struct unix_sock *u = unix_sk(sk);
 			struct sk_buff *skb;
 			int answ = 0;
 
+			mutex_lock(&u->iolock);
+
 			skb = skb_peek(&sk->sk_receive_queue);
-			if (skb && skb == READ_ONCE(unix_sk(sk)->oob_skb))
-				answ = 1;
+			if (skb) {
+				struct sk_buff *oob_skb = READ_ONCE(u->oob_skb);
+
+				if (skb == oob_skb ||
+				    (!oob_skb && !unix_skb_len(skb)))
+					answ = 1;
+			}
+
+			mutex_unlock(&u->iolock);
+
 			err = put_user(answ, (int __user *)arg);
 		}
 		break;