From 4b5f8e608749b7e8fa386c6e4301cf9272595859 Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Wed, 27 May 2026 04:59:18 +0000 Subject: [PATCH] Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close() calls iso_sock_clear_timer() before acquiring lock_sock(sk). iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the socket lock held: if (!iso_pi(sk)->conn) return; cancel_delayed_work(&iso_pi(sk)->conn->timeout_work); Concurrently, iso_conn_del() executes under lock_sock(sk) and calls iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in the final reference to the connection being dropped: CPU0 CPU1 ---- ---- iso_sock_clear_timer() if (conn != NULL) ... lock_sock(sk) iso_chan_del() iso_pi(sk)->conn = NULL cancel_delayed_work(conn) /* NULL deref or UAF */ iso_pi(sk)->conn is not stable across the unlock window, causing a NULL pointer dereference or use-after-free. Serialize iso_sock_clear_timer() with the socket lock by moving it inside lock_sock()/release_sock(), matching the pattern used in iso_conn_del() and all other call sites. Fixes: ccf74f2390d60a2f9a75ef496d2564abb478f46a ("Bluetooth: Add BTPROTO_ISO socket type") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/iso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index f03b7fa5dccc..876649556d3c 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -864,8 +864,8 @@ static void __iso_sock_close(struct sock *sk) /* Must be called on unlocked socket. */ static void iso_sock_close(struct sock *sk) { - iso_sock_clear_timer(sk); lock_sock(sk); + iso_sock_clear_timer(sk); __iso_sock_close(sk); release_sock(sk); iso_sock_kill(sk);