From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 D13122D660E; Wed, 10 Sep 2025 09:22:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757496180; cv=none; b=XV3yR5utYT4RKoGCWNgv7YjiLvnm/a3MM2XVss5k36yfFagePVWeJO947UIEwGXCi5TiD/q0Vr7masE/BsAjGQU5kb2o3SgPmnHOTxYTuOIDiwBBrElF1AJ29Me+zVR7tZZkwZwI6Gfso1pafarNFW812Z3gkVcywsypRUQlCrk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757496180; c=relaxed/simple; bh=yd0ny0R9oIhP7Ea9IXvlxJK03B0rSJN5DFpKsoJYET8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BmdeDTHquIdNAcqB6Wye4IazvrAVq7YWY8ED7FYy7U9gIZ6OCY0TALBtc5vYk0GcQJ6GevmJg6k1olvCCsG+p9+JYsv+dUL39pEFO0Czi7agbPbm43XucX42cpFpY60RRz/tvDUT9cr0s3cPZUy99UlMUBK+o1PIMjjkxxGA1JQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=ORl1h+mf; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ORl1h+mf" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id AC2EFDAB; Wed, 10 Sep 2025 11:21:42 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1757496102; bh=yd0ny0R9oIhP7Ea9IXvlxJK03B0rSJN5DFpKsoJYET8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ORl1h+mfxb6QAugG0FoJkjw8EykOpXQyVGC7RBKF7svrsjkFQucQZAgOJfsWeNqPU 03HAdGcuhIRCK4xYuBhvrFFm4GTqUc9utCO/jOrq3n9ZAPjfHoZos6pDiqj8GVJZY5 6Xi+mvGISLffWEU0xIvIPa5IfvDwoh0auPIOUQWk= Date: Wed, 10 Sep 2025 12:22:33 +0300 From: Laurent Pinchart To: Edward Adam Davis Cc: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org, sakari.ailus@linux.intel.com, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH Next] media: mc: Clear minor number before put device Message-ID: <20250910092233.GA20904@pendragon.ideasonboard.com> References: <68c097c5.050a0220.3c6139.000a.GAE@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Hello Edward, On Wed, Sep 10, 2025 at 09:15:27AM +0800, Edward Adam Davis wrote: > The device minor should not be cleared after the device is released. The most important piece of information in a commit message is the reason for the patch. You need to explain *why* this is needed, not just state it should be done. > Fixes: 9e14868dc952 ("media: mc: Clear minor number reservation at unregistration time") > Reported-by: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=031d0cfd7c362817963f > Tested-by: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com > Signed-off-by: Edward Adam Davis > --- > drivers/media/mc/mc-devnode.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c > index 0d01cbae98f2..6daa7aa99442 100644 > --- a/drivers/media/mc/mc-devnode.c > +++ b/drivers/media/mc/mc-devnode.c > @@ -276,13 +276,10 @@ void media_devnode_unregister(struct media_devnode *devnode) > /* Delete the cdev on this minor as well */ > cdev_device_del(&devnode->cdev, &devnode->dev); > devnode->media_dev = NULL; > + clear_bit(devnode->minor, media_devnode_nums); > mutex_unlock(&media_devnode_lock); > > put_device(&devnode->dev); > - > - mutex_lock(&media_devnode_lock); > - clear_bit(devnode->minor, media_devnode_nums); > - mutex_unlock(&media_devnode_lock); > } > > /* -- Regards, Laurent Pinchart