From: Hillf Danton <hdanton@sina.com>
To: Safa Karakus <safa.karakus@secunnix.com>
Cc: linux-bluetooth@vger.kernel.org,
Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
Marcel Holtmann <marcel@holtmann.org>,
stable@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()
Date: Sun, 17 May 2026 06:40:00 +0800 [thread overview]
Message-ID: <20260516224002.754-1-hdanton@sina.com> (raw)
In-Reply-To: <20260516181504.3076260-1-safa.karakus@secunnix.com>
On Sat, 16 May 2026 21:15:04 +0300 Safa Karakus wrote:
> bt_accept_dequeue() unlinks a not-yet-accepted child from the parent
> accept queue and release_sock()s it before returning, so the returned
> sk has no caller reference and is unlocked.
>
> l2cap_sock_cleanup_listen() walks these children on listening-socket
> close. A concurrent HCI disconnect drives hci_rx_work ->
> l2cap_conn_del() which runs l2cap_chan_del() + l2cap_sock_kill() and
> frees the child sk and its l2cap_chan; cleanup_listen() then uses both:
>
> BUG: KASAN: slab-use-after-free in l2cap_sock_kill
> l2cap_sock_kill / l2cap_sock_cleanup_listen / __x64_sys_close
> Freed by: l2cap_conn_del -> l2cap_sock_close_cb -> l2cap_sock_kill
>
Feel free to add the regular KASAN uaf calltrace to help understand your fix.
prev parent reply other threads:[~2026-05-16 22:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-28 23:30 [PATCH] Bluetooth: l2cap: fix UAF race in l2cap_sock_cleanup_listen Safa Karakuş
2026-04-29 0:37 ` bluez.test.bot
2026-04-30 17:17 ` [PATCH] " Luiz Augusto von Dentz
2026-05-16 9:21 ` [PATCH v3] Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del() Safa Karakuş
2026-05-16 10:18 ` [v3] " bluez.test.bot
2026-05-16 18:15 ` [PATCH v4] " Safa Karakuş
2026-05-16 20:47 ` [v4] " bluez.test.bot
2026-05-16 22:40 ` Hillf Danton [this message]
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