Re: [syzbot] Re: [syzbot] [bluetooth?] BUG: corrupted list in hci_chan_del (2)

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Subject: Re: [syzbot] [bluetooth?] BUG: corrupted list in hci_chan_del (2)
Author: lizhi.xu@xxxxxxxxxxxxx

old logical will make get/put unbalance in l2cap_recv_acldata.
so remote get/put conn.

#syz test

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index adb8c33ac595..503626f70be5 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -7497,8 +7497,6 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 	if (!conn)
 		conn = l2cap_conn_add(hcon);
 
-	conn = l2cap_conn_hold_unless_zero(conn);
-
 	hci_dev_unlock(hcon->hdev);
 
 	if (!conn)
@@ -7592,8 +7590,6 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 		break;
 	}
 
-	l2cap_conn_put(conn);
-
 drop:
 	kfree_skb(skb);
 }