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 09E143B47E5; Tue, 21 Jul 2026 20:37:47 +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=1784666271; cv=none; b=athCRS1hwd0zlEN/FyWNzT4ldsxs/ki6NxGuZhSs2m8jc8agxKp4PYmDsfv9SWaWr/BFD1z78Rq/AkS3cBlLGZGNu+R8pRFMYPZH+ybpqOqm7EOchL/k2uAqtsAhj+VBL4EvoEAFn9YcVFfQ2pD/NNl/LvqDYpzRJN0lXo8U6a8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666271; c=relaxed/simple; bh=F2/nKcmtk3Uk+PuHkqxRD96xTH0LB0aZH96Cd1wwOZs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VbobKdewx/DXlk4+FyhdgKwzrU/zE5l8B3WYkxkL56wXya92A5PyJOBMy69p6xEiqcywIoPPDWo5VY0gtf0tYnDBC45LGHrDUYNq8eOuKrI3XqvChSMwgrPYUkdV8D0rmdCbDvymH0x2mpD8t4wLRK8QHI0YoxhawQIVJ5vD5Vw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=heVHuuC0; 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="heVHuuC0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C8301F000E9; Tue, 21 Jul 2026 20:37:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784666266; bh=iAFO9lJoX7AcGbvKTQaIFUvODMbYkAOXxFP6Fl43emw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=heVHuuC0ffPr8y5jt0QjJ2NMdJCAUAHcSjJ5vF8VoHp8ePkeHuQLHZqbxvYNP6XJj awVMjP1ha/+mj00D06kcSmHc4Ix9aVqxSf5hiNf5cRwgOXheobspqoRqXwrh5lb0Fk lZkvQWy2WnNGbfQiGXJ+W28g3Tl1fYxQufQH+kMo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Guangshuo Li , Sasha Levin Subject: [PATCH 6.6 0618/1266] staging: most: video: avoid double free on video register failure Date: Tue, 21 Jul 2026 17:17:35 +0200 Message-ID: <20260721152455.692077195@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@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 6.6-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 6254a5df2502fa..a2fd7681c2610b 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