Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in sco_sock_connect

Edward Adam Davis
2024-11-25T14:55:47Z

add conn should not put. timeout handler miss a put when !hcon.

#syz test

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 1b8e468d24cf..78f7bca24487 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -143,6 +143,7 @@ static void sco_sock_timeout(struct work_struct *work)
sco_conn_lock(conn);
if (!conn->hcon) {
sco_conn_unlock(conn);
+ sco_conn_put(conn);
return;
}
sk = sco_sock_hold(conn);
@@ -192,7 +193,6 @@ static struct sco_conn *sco_conn_add(struct hci_conn *hcon)
conn->hcon = hcon;
sco_conn_unlock(conn);
}
- sco_conn_put(conn);
return conn;
}