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Message-ID: <tencent_748DB7122CDDCBDDB29965CF870D9225BF07@qq.com>
From: Edward Adam Davis <eadavis@qq.com>
To: syzbot+1d37bef05da87b99c5a6@syzkaller.appspotmail.com
Cc: linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [can?] memory leak in j1939_netdev_start
Date: Wed, 24 Jan 2024 09:24:34 +0800
In-Reply-To: <00000000000060446d060af10f08@google.com>
References: <00000000000060446d060af10f08@google.com>
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please test memory leak in j1939_netdev_start

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index 14c431663233..1d1f1348eeca 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -141,6 +141,7 @@ static void j1939_sk_queue_drop_all(struct j1939_priv *priv,
 				 sk_session_queue_entry) {
 		list_del_init(&session->sk_session_queue_entry);
 		session->err = err;
+		printk("s: %p, %s\n", session, __func__);
 		j1939_session_put(session);
 	}
 	spin_unlock_bh(&jsk->sk_session_queue_lock);
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index fe3df23a2595..4e5f6037db46 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -283,6 +283,7 @@ static void j1939_session_destroy(struct j1939_session *session)
 	}
 	__j1939_session_drop(session);
 	j1939_priv_put(session->priv);
+	printk("free session: %p, %s\n", session, __func__);
 	kfree(session);
 }
 
@@ -1552,6 +1553,8 @@ j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
 	/* alloc data area */
 	skb_put(skb, size);
 	/* skb is recounted in j1939_session_new() */
+	printk("s: %p, skb: %p, size: %d, csk: %d, %s\n", 
+		session, skb, size, sizeof(struct can_skb_priv), __func__);
 	return session;
 }
 
@@ -1758,6 +1761,7 @@ static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
 		j1939_tp_set_rxtimeout(session, 1250);
 	}
 
+	printk("s: %p, %s\n", session, __func__);
 	j1939_session_put(session);
 }
 
@@ -2005,6 +2009,8 @@ struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
 	if (!session)
 		return ERR_PTR(-ENOMEM);
 
+	printk("s: %p, size: %d, %s\n", session, size, __func__);
+
 	/* skb is recounted in j1939_session_new() */
 	sock_hold(skb->sk);
 	session->sk = skb->sk;