From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793801911; b=OOn9tF0jXPYKWxjQf5YFqMLbrJUyhFq5ojyM6EU2/Q1u255wREnbXBYyUUTiB067oJhi M1kr8kOSe5E7rcA3QtLk1iVxdUb0GuFgrKchBC6rMhPQtUau0POKV+aQTtOt+/HkpTkwG LoP0dVzDW7K54PUeNU/U7B2g2K0ARowpeEcEo5+DT+BRr3I6VrNfowKueREqbQK6m+SJF 0hHXa2S1xLrpQXcxXysch32wY4kIH95V5lJYzL/0kiZkdVn2z1iu4/rKoXIRe1EULmb5+ H7RiQLfNSLIsT5PbG0uq/viPTte55UnS4MvelKFMvOMtdTmRoN5KkIVKBEV7MDh9new== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793801911; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=fCAhFOURndiwJONdm2GA3T4cB3PqNwh1g0yoAJF98Wk=; b=lZ/1xfmfye1BHreQL9Od2DlKHXUnQqame9YPkJh8a1KHQhURWPM8wjh8Q/vSEEC2y+pB SYdN+cwAWc4fYT6nkvfOMNILn9ib6ZZsYmQBMd/voy3fpZEl9Na8StpIGnSfN6ox52Lo/ w3WC3CQt9IifPKDdfG54WJa1BjuPXCmJaoDDt1nCXmMKI6o+NA7gruLnNE4bNok7/I52o 64j7+1e+HyxOv4wGs+AjixoZWpwAJ3oEvi689QxSPMi6P5JPI7ECOhyC73Lb8Pc2rjnoJ qrNSSnfpEN0iFa6VTAN0ORWUUnyppomEjpiPfIiNVGtbNiYZEw5M+9jf8+vkDnxf0Ng== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="pOPepz/L"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 49448606A31B for ; Wed, 4 Nov 2026 14:18:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=pOPepz/L Received: by smtp.kernel.org (Postfix) with ESMTPSA id A23F71F000C1; Wed, 4 Nov 2026 14:18:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793801910; bh=fCAhFOURndiwJONdm2GA3T4cB3PqNwh1g0yoAJF98Wk=; h=Subject:To:Cc:From:Date; b=pOPepz/Luh1gH3GagsqyfMRx5dMDi1KrB50+uXcgCyS/DyQHsSMGZtcBApCYSPuo6 MUEoPEJ1/F07ra5+ydpiUZyVxhyMbrifnsBjnHJS1xibgk88EM92T1MX5oUtbk1Ex7 s9DTcs0JeSu3V37EML6We5B9ooEaQVGoQLqDYj+A= Subject: FAILED: patch "[PATCH] media: s5p-mfc: use timer_shutdown_sync() for the" failed to apply to 6.6-stable tree To: fanwu01@zju.edu.cn,andrzej.hajda@intel.com,hverkuil+cisco@kernel.org,m.szyprowski@samsung.com,nicolas.dufresne@collabora.com Cc: From: Date: Wed, 04 Nov 2026 15:18:26 +0100 Message-ID: <2026110426-scrutiny-value-3242@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 63069b5917cba2e15b1a78b3f4ff99e45102c56f # git commit -s git send-email --to '' --in-reply-to '2026110426-scrutiny-value-3242@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 63069b5917cba2e15b1a78b3f4ff99e45102c56f Mon Sep 17 00:00:00 2001 From: Fan Wu Date: Thu, 30 Jul 2026 07:15:52 +0000 Subject: [PATCH] media: s5p-mfc: use timer_shutdown_sync() for the self-rearming watchdog The MFC watchdog timer (s5p_mfc_watchdog) is self-rearming: every callback re-arms itself with add_timer() and, on a timeout, schedules watchdog_work. s5p_mfc_remove() tears this down with timer_delete_sync() followed by flush_work(). timer_delete_sync() dequeues the timer and waits for a callback that is already running, but it does not prevent a subsequent re-arm. Because the watchdog callback re-arms via add_timer(), this is the wrong shutdown primitive: once the wait returns nothing guarantees a just-queued re-arm will not fire later, dereferencing dev (clock on/off, deinit_hw, load_firmware, init_hw) after video_unregister_device(), DMA teardown and s5p_mfc_final_pm() have run, a potential use-after-free. Use timer_shutdown_sync(), which puts the timer into a shutdown state so that any add_timer()/mod_timer() from the callback becomes a no-op and no later firing is possible. Switch flush_work() to cancel_work_sync() so any watchdog_work that was already queued before the timer was stopped is cancelled rather than allowed to run to completion against the torn-down device. This issue was found by an in-house static analysis tool. No runtime reproducer is available. Fixes: af9357467810 ("[media] MFC: Add MFC 5.1 V4L2 driver") Cc: stable@vger.kernel.org Cc: Andrzej Hajda Assisted-by: Codex:gpt-5.6 Signed-off-by: Fan Wu Reviewed-by: Marek Szyprowski Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c index 32eb402d439c..03e7eac8d1f7 100644 --- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c +++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c @@ -1474,8 +1474,8 @@ static void s5p_mfc_remove(struct platform_device *pdev) } mutex_unlock(&dev->mfc_mutex); - timer_delete_sync(&dev->watchdog_timer); - flush_work(&dev->watchdog_work); + timer_shutdown_sync(&dev->watchdog_timer); + cancel_work_sync(&dev->watchdog_work); video_unregister_device(dev->vfd_enc); video_unregister_device(dev->vfd_dec);