From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3602546EC78; Tue, 21 Jul 2026 19:33:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784662421; cv=none; b=MYPKp+E1WKSN3JRBVTPZxI1jVxceAijEPtYDJsmwGTYxn9mvlc2yx94H/JTMe7eUEUMSAxWYNAmAeOxJpWC3Nc6trK5mYxDKy1BhrjukFtdMc7hLFOhAexXVQLgGvnQC2PalSopwNcHolwtrw911MtFybmyOnph48902wUo9KBI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784662421; c=relaxed/simple; bh=+LuHSCuHE+ASDrur4rZYaLH7yMKRwk16IAoomd45qfk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oqWo1AmGP7jmNQtrgqBMGGCfJiSm/DS+3edCb3XJ5NpJGx18S/6wwCIyPY+QXJioa/gvVqd4uE/OUEp1rjaPeXmOTpVysjw1/S2VI07zciDUtdlHUJflDqQq0lstpyuLcnyR+zojT9EWgrPwciKCWlajt95MMc+ldKS4Z54O/EU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0fs4wCvQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0fs4wCvQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AA281F000E9; Tue, 21 Jul 2026 19:33:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784662420; bh=vDb6qhHFS74Xfz7izMzeiVCndRM8lrp3WahWWkyUdHw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=0fs4wCvQdNca9AGQxVx7axSKcKmowIoM+WvV/2SkDgj1tD5mqSilXZKbt9iYQPURN rvcyh90O0MgQkb8oPeXtgDlLmRRnlMpTrf+W0r2Fmd9yR5VvmEd5KHBjhfY9KX/K+k e3IaAG53wV3C5ANPeqI44hTUOTIufpwYrCbRzvWI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Guangshuo Li , Sasha Levin Subject: [PATCH 6.12 0438/1276] staging: most: video: avoid double free on video register failure Date: Tue, 21 Jul 2026 17:14:41 +0200 Message-ID: <20260721152455.904188557@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guangshuo Li [ Upstream commit 7cb1c5b32a2bfde961fff8d5204526b609bcb30a ] comp_register_videodev() allocates a video_device with video_device_alloc() and releases it if video_register_device() fails. This can double free the video_device when __video_register_device() reaches device_register() and that call fails: video_register_device() -> __video_register_device() -> device_register() fails -> put_device(&vdev->dev) -> v4l2_device_release() -> vdev->release(vdev) -> video_device_release(vdev) comp_register_videodev() -> video_device_release(mdev->vdev) Use video_device_release_empty() while registering the device so that registration failure paths do not free mdev->vdev through vdev->release(). comp_register_videodev() then releases mdev->vdev exactly once on failure. Restore video_device_release() after successful registration so the registered device keeps its normal lifetime handling. This issue was found by a static analysis tool I am developing. Fixes: eab231c0398a ("staging: most: v4l2-aim: remove unnecessary label err_vbi_dev") Signed-off-by: Guangshuo Li Link: https://patch.msgid.link/20260517111218.945796-1-lgs201920130244@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/staging/most/video/video.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/staging/most/video/video.c b/drivers/staging/most/video/video.c index 2b3cdb1ce1404c..60d554e74b268e 100644 --- a/drivers/staging/most/video/video.c +++ b/drivers/staging/most/video/video.c @@ -415,6 +415,7 @@ static int comp_register_videodev(struct most_video_dev *mdev) /* Fill the video capture device struct */ *mdev->vdev = comp_videodev_template; + mdev->vdev->release = video_device_release_empty; mdev->vdev->v4l2_dev = &mdev->v4l2_dev; mdev->vdev->lock = &mdev->lock; snprintf(mdev->vdev->name, sizeof(mdev->vdev->name), "MOST: %s", @@ -427,9 +428,13 @@ static int comp_register_videodev(struct most_video_dev *mdev) v4l2_err(&mdev->v4l2_dev, "video_register_device failed (%d)\n", ret); video_device_release(mdev->vdev); + return ret; } - return ret; + mdev->vdev->release = video_device_release; + + return 0; + } static void comp_unregister_videodev(struct most_video_dev *mdev) -- 2.53.0