From: Markus Elfring <Markus.Elfring@web.de>
To: Cen Zhang <zzzccc427@gmail.com>, linux-bluetooth@vger.kernel.org
Cc: Cen Zhang <zzzccc427@163.com>,
LKML <linux-kernel@vger.kernel.org>,
Johan Hedberg <johan.hedberg@gmail.com>,
Luiz Von Dentz <luiz.dentz@gmail.com>,
Marcel Holtmann <marcel@holtmann.org>
Subject: Re: [PATCH] Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once
Date: Sun, 28 Sep 2025 13:39:03 +0200 [thread overview]
Message-ID: <9b865b1f-fd7f-4378-a512-2c67dfff675f@web.de> (raw)
In-Reply-To: <20250928110740.137220-1-zzzccc427@163.com>
> hci_cmd_sync_dequeue_once() does lookup and then cancel
> the entry under two separate lock sections. Meanwhile,
> hci_cmd_sync_work() can also delete the same entry,
> leading to double list_del() and "UAF".
You may occasionally put more than 55 characters into text lines
of such a change description.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.17-rc7#n658
> Fix this by holding cmd_sync_work_lock across both
> lookup and cancel, so that the entry cannot be removed
> concurrently.
…
> +++ b/net/bluetooth/hci_sync.c
> @@ -862,12 +862,13 @@ bool hci_cmd_sync_dequeue_once(struct hci_dev *hdev,
…
* How do you think about to add any tags (like “Fixes” and “Cc”) accordingly?
* Under which circumstances would you become interested to apply a call
like “scoped_guard(mutex, &hdev->cmd_sync_work_lock)”?
https://elixir.bootlin.com/linux/v6.17-rc7/source/include/linux/mutex.h#L228
Regards,
Markus
prev parent reply other threads:[~2025-09-28 11:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-28 11:07 Cen Zhang
2025-09-28 11:39 ` Markus Elfring [this message]
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