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 DC61B2F25E4 for ; Fri, 3 Oct 2025 13:12:54 +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=1759497174; cv=none; b=a+vsGZdgvXvuidx8zyIM9RIlq+t553u5q5uvSFWQBUiX6RVefisR3WsxiSjZpNM8PEamTJ/CRpqojmC2BwLRVUgtM80vGmT4BP+dkr2mKkrJHKStJbjitHs+htzqG5s4akUZxk9h3Qhni/c+DVt6BkL+YJA4R+RpyzJ/B84SMQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759497174; c=relaxed/simple; bh=RmfnfVp14Rfdt85nxH0jLi3aMfWii+B0AI32Y6tJtSc=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=i+h/C+t64wAts+ksRdgLVz5f/pWr/bom7jivJOBxbR1qIPWzyqn2Vcgkxs7yD3a3xZBYDgMNZTQAN++UfV8FXZwYhTQBozAS99PyvF4PdusfnglqoOVRx53b6QxTN4E3TILINRlHH7kM6nBV4M6VqHCRwKoEsDw8ArjZoO1hbZM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=f+tGh2I6; 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="f+tGh2I6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1756BC4CEF5; Fri, 3 Oct 2025 13:12:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1759497174; bh=RmfnfVp14Rfdt85nxH0jLi3aMfWii+B0AI32Y6tJtSc=; h=Subject:To:Cc:From:Date:From; b=f+tGh2I6ZyRWlbIxGdPX/URYSKh89RFpEaL2yUIfNt5jameVkRNRihQBsfIMUTZ9m s/Lw9bAoP5QTp6bhoVkboQjXHgY9Obj2oxQzstLwIoZKpFF/dtsScvSaBuE2KklJzk lWOKy/gUd4SPCMHHwpVqpalX7fEBX9zJnK3Dtodg= Subject: FAILED: patch "[PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release [hverkuil: fix typo in tunner -> tuner]" failed to apply to 6.6-stable tree To: duoming@zju.edu.cn,hverkuil+cisco@kernel.org Cc: From: Date: Fri, 03 Oct 2025 15:12:39 +0200 Message-ID: <2025100338-ambulance-swaddling-4b2b@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 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 40b7a19f321e65789612ebaca966472055dab48c # git commit -s git send-email --to '' --in-reply-to '2025100338-ambulance-swaddling-4b2b@gregkh' --subject-prefix 'PATCH 6.6.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); }