This is a note to let you know that I've just added the patch titled
[media] videobuf2-v4l2: Verify planes array in buffer dequeueing
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
videobuf2-v4l2-verify-planes-array-in-buffer-dequeueing.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 83934b75c368f529d084815c463a7ef781dc9751 Mon Sep 17 00:00:00 2001
From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Date: Sun, 3 Apr 2016 16:31:03 -0300
Subject: [media] videobuf2-v4l2: Verify planes array in buffer dequeueing
From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
commit 83934b75c368f529d084815c463a7ef781dc9751 upstream.
When a buffer is being dequeued using VIDIOC_DQBUF IOCTL, the exact buffer
which will be dequeued is not known until the buffer has been removed from
the queue. The number of planes is specific to a buffer, not to the queue.
This does lead to the situation where multi-plane buffers may be requested
and queued with n planes, but VIDIOC_DQBUF IOCTL may be passed an argument
struct with fewer planes.
__fill_v4l2_buffer() however uses the number of planes from the dequeued
videobuf2 buffer, overwriting kernel memory (the m.planes array allocated
in video_usercopy() in v4l2-ioctl.c) if the user provided fewer
planes than the dequeued buffer had. Oops!
Fixes: b0e0e1f83de3 ("[media] media: videobuf2: Prepare to divide videobuf2")
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/videobuf2-v4l2.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -67,6 +67,11 @@ static int __verify_planes_array(struct
return 0;
}
+static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)
+{
+ return __verify_planes_array(vb, pb);
+}
+
/**
* __verify_length() - Verify that the bytesused value for each plane fits in
* the plane length and that the data offset doesn't exceed the bytesused value.
@@ -432,6 +437,7 @@ static int __fill_vb2_buffer(struct vb2_
}
static const struct vb2_buf_ops v4l2_buf_ops = {
+ .verify_planes_array = __verify_planes_array_core,
.fill_user_buffer = __fill_v4l2_buffer,
.fill_vb2_buffer = __fill_vb2_buffer,
.set_timestamp = __set_timestamp,
Patches currently in stable-queue which might be from sakari.ailus@xxxxxxxxxxxxxxx are
queue-4.4/vb2-core-skip-planes-array-verification-if-pb-is-null.patch
queue-4.4/videobuf2-v4l2-verify-planes-array-in-buffer-dequeueing.patch
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