From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com [210.118.77.12]) (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 E79E229BDA3 for ; Thu, 23 Oct 2025 11:55:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.118.77.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761220548; cv=none; b=fIl2RkuNo1U2G2Gcgyv4L92+UIQT1SL08Wf6Xhtq417/hc73WG6sw/mc38OlmjtVLI7dWOzmjv7IHxYeOZtHRFLk8TstkLJ/kMRK05EoDn9L6pK/T+u92J7tw6tOlN39+hpSu7qajs7jhAOMw2vWBTCK58tqrqJlNqEFVkDUTIU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761220548; c=relaxed/simple; bh=jpqlOQFQ0lCsBU/ukJf92pGlz0eJx9vhQf0m3jE70sM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:From:In-Reply-To: Content-Type:References; b=RwZOmoaCqGsqoFdfvXupljpKal5rVaz0SkJGEXAih3hVrdjFxNBuLZG0AzWkUUKRIPwtcz7u0wMcKIc6tN6Wv4r2vgBAt7EgTuFlqrstz8kMqkIgfA/UMHxNW9sRUByM6raNkQVxYH3k+2/nj/iOPigTb1Q5fw3o0cLzZimqHNA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=PO19t8ZW; arc=none smtp.client-ip=210.118.77.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="PO19t8ZW" Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout2.w1.samsung.com (KnoxPortal) with ESMTP id 20251023115544euoutp02188ad5ab17d82fc950606f78103d1c90~xHMDwl-8Q0657406574euoutp02o for ; Thu, 23 Oct 2025 11:55:44 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w1.samsung.com 20251023115544euoutp02188ad5ab17d82fc950606f78103d1c90~xHMDwl-8Q0657406574euoutp02o DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1761220544; bh=hkfNeWXTF4q43g0m16pkbTb1R8n6c2a48SB9tENaQRE=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=PO19t8ZWx9P6e1iyt+TiwyFwiTHTv3qKCJVUJxsEkC1q6RHjk9xMZTBZ5HnGBZ7vt 2yxkdN757SIm7iSxK58aszxb10N1G4XN6ktmTKpALXIebRPA0rA8i6q8K8sc7pwEx2 vBDuDwZEEukJH4xGjv6cNis/2nVuVlnfgFiGjoiE= Received: from eusmtip1.samsung.com (unknown [203.254.199.221]) by eucas1p2.samsung.com (KnoxPortal) with ESMTPA id 20251023115543eucas1p2fa905f7a756b96653fd64f0692d1e23e~xHMDZpWj53189131891eucas1p2Z; Thu, 23 Oct 2025 11:55:43 +0000 (GMT) Received: from [106.210.134.192] (unknown [106.210.134.192]) by eusmtip1.samsung.com (KnoxPortal) with ESMTPA id 20251023115542eusmtip1ec5d85b05192ce23dd62b70994d5b0a9~xHMCaM8Ie0113301133eusmtip1b; Thu, 23 Oct 2025 11:55:42 +0000 (GMT) Message-ID: <85aa56ff-098b-4db1-9de5-05b0f306623f@samsung.com> Date: Thu, 23 Oct 2025 13:55:42 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Betterbird (Windows) Subject: Re: [PATCH v3] media: videobuf2: forbid remove_bufs when legacy fileio is active To: Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tomasz Figa , Mauro Carvalho Chehab , Guennadi Liakhovetski , Benjamin Gaignard , Hans Verkuil , stable@vger.kernel.org, Shuangpeng Bai Content-Language: en-US From: Marek Szyprowski In-Reply-To: <81a46647-c666-4475-893b-d4af043c90ea@kernel.org> Content-Transfer-Encoding: 7bit X-CMS-MailID: 20251023115543eucas1p2fa905f7a756b96653fd64f0692d1e23e X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20251023113101eucas1p2c227985b0198d888564cab00aeb94f01 X-EPHeader: CA X-CMS-RootMailID: 20251023113101eucas1p2c227985b0198d888564cab00aeb94f01 References: <20251023113052.1303082-1-m.szyprowski@samsung.com> <81a46647-c666-4475-893b-d4af043c90ea@kernel.org> On 23.10.2025 13:36, Hans Verkuil wrote: > On 23/10/2025 13:30, Marek Szyprowski wrote: >> vb2_ioctl_remove_bufs() call manipulates queue internal buffer list, >> potentially overwriting some pointers used by the legacy fileio access >> mode. Add a vb2_verify_memory_type() check symmetrical to >> vb2_ioctl_create_bufs() to forbid that ioctl when fileio is active to >> protect internal queue state between subsequent read/write calls. >> >> CC: stable@vger.kernel.org >> Fixes: a3293a85381e ("media: v4l2: Add REMOVE_BUFS ioctl") >> Reported-by: Shuangpeng Bai >> Suggested-by: Benjamin Gaignard >> Signed-off-by: Marek Szyprowski >> --- >> drivers/media/common/videobuf2/videobuf2-v4l2.c | 8 +++++--- >> 1 file changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c >> index d911021c1bb0..a8a5b42a42d0 100644 >> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c >> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c >> @@ -1000,13 +1000,15 @@ int vb2_ioctl_remove_bufs(struct file *file, void *priv, >> struct v4l2_remove_buffers *d) >> { >> struct video_device *vdev = video_devdata(file); >> - >> - if (vdev->queue->type != d->type) >> - return -EINVAL; >> + int res; >> >> if (d->count == 0) >> return 0; > Ah, no. This should still check d->type. So: > > if (d->count == 0) > return d->type == vdev->queue->type ? 0 : -EINVAL; Then frankly speaking lets get back to v1 limited to vb2_ioctl_remove_bufs(), as using vb2_verify_memory_type() in this context only makes things harder to understand: diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index d911021c1bb0..f4104d5971dd 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -1010,6 +1015,11 @@ int vb2_ioctl_remove_bufs(struct file *file, void *priv, if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; + if (vb2_fileio_is_active(vdev->queue)) { + dprintk(vdev->queue, 1, "file io in progress\n"); + return -EBUSY; + } + return vb2_core_remove_bufs(vdev->queue, d->index, d->count); } EXPORT_SYMBOL_GPL(vb2_ioctl_remove_bufs); > Regards, > > Hans > >> >> + res = vb2_verify_memory_type(vdev->queue, vdev->queue->memory, d->type); >> + if (res) >> + return res; >> + >> if (vb2_queue_is_busy(vdev->queue, file)) >> return -EBUSY; >> Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland