From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0DB8B1C2334 for ; Fri, 3 Oct 2025 13:13:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759497190; cv=none; b=VH7uO3rw+Mr/a5j81tSisBMuJgGhwG+zRIlX4gFYQDoumXsbP0c7s4vFew613uLGhu3Ti8TYDJdKsXMFonvxmFju+S+aBRejTrERpc8gtl/JV+tROPQOTSmJiSXoKHWQ7VgPbkgDCzLGszrtNMgAZzH6qr30RMpm3ppcge1jpDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759497190; c=relaxed/simple; bh=a+MTtxeoagXguXl5hnSQni8/dsfGpF3bkJQvgCil0Nw=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=I0mSoew6y0IvuN8+ahvn/bycucCI96Bzpcmy3P+Ror7ZNa8hSy8gsb0eXp8LPhevooqePxPgZFuAxGaH9oqtHxmo6OdkWZjSBwLyUbsiMQ/V85BOnXjiZowg2XmoFEnaWlOVFtAWAfVLI/KrNcAwkatvBqgF3ku7DreQnB6dPHA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wKjmUvxb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wKjmUvxb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0DA8FC4CEF5; Fri, 3 Oct 2025 13:13:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1759497185; bh=a+MTtxeoagXguXl5hnSQni8/dsfGpF3bkJQvgCil0Nw=; h=Subject:To:Cc:From:Date:From; b=wKjmUvxbUoR1yAGa6T1Llm9nDgGfeAAOs52QMSBxQlPkejQiGEGdor8sj1dCi6K32 zwxM2Rqk36B9OJmavg+/RfHnESHz+H1XRdcr+oca3OG1pvO3VMnLxHcutCPGShb+c9 tZnHJGQsxlan4FGj5WBTZ3TVUqq857+y0i98QIa0= Subject: FAILED: patch "[PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release [hverkuil: fix typo in tunner -> tuner]" failed to apply to 5.4-stable tree To: duoming@zju.edu.cn,hverkuil+cisco@kernel.org Cc: From: Date: Fri, 03 Oct 2025 15:12:41 +0200 Message-ID: <2025100341-dime-left-e15f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 5.4-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-5.4.y git checkout FETCH_HEAD git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c # git commit -s git send-email --to '' --in-reply-to '2025100341-dime-left-e15f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001 From: Duoming Zhou Date: Wed, 17 Sep 2025 17:56:08 +0800 Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release The original code uses cancel_delayed_work() in xc5000_release(), which does not guarantee that the delayed work item timer_sleep has fully completed if it was already running. This leads to use-after-free scenarios where xc5000_release() may free the xc5000_priv while timer_sleep is still active and attempts to dereference the xc5000_priv. A typical race condition is illustrated below: CPU 0 (release thread) | CPU 1 (delayed work callback) xc5000_release() | xc5000_do_timer_sleep() cancel_delayed_work() | hybrid_tuner_release_state(priv) | kfree(priv) | | priv = container_of() // UAF Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the timer_sleep is properly canceled before the xc5000_priv memory is deallocated. A deadlock concern was considered: xc5000_release() is called in a process context and is not holding any locks that the timer_sleep work item might also need. Therefore, the use of the _sync() variant is safe here. This bug was initially identified through static analysis. Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds") Cc: stable@vger.kernel.org Signed-off-by: Duoming Zhou Signed-off-by: Hans Verkuil [hverkuil: fix typo in Subject: tunner -> tuner] diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c index bf4ff461e082..a28481edd22e 100644 --- a/drivers/media/tuners/xc5000.c +++ b/drivers/media/tuners/xc5000.c @@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe) mutex_lock(&xc5000_list_mutex); if (priv) { - cancel_delayed_work(&priv->timer_sleep); + cancel_delayed_work_sync(&priv->timer_sleep); hybrid_tuner_release_state(priv); }