| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 092/163] [media] vb2-memops: Fix over allocation of frame vectors | Date | Mon, 2 May 2016 17:12:00 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
commit 89a095668304e8a02502ffd35edacffdbf49aa8c upstream.
On page unaligned frames, create_framevec forces get_vaddr_frames to allocate an extra page at the end of the buffer. Under some circumstances, this leads to -EINVAL on VIDIOC_QBUF.
E.g: We have vm_a that vm_area that goes from 0x1000 to 0x3000. And a frame that goes from 0x1800 to 0x2800, i.e. 2 pages.
frame_vector_create will be called with the following params:
get_vaddr_frames(0x1800, 2, write, 1, vec);
get_vaddr will allocate the first page after checking that the memory 0x1800-0x27ff is valid, but it will not allocate the second page because the range 0x2800-0x37ff is out of the vm_a range. This results in create_framevec returning -EFAULT
Error Trace: [ 9083.793015] video0: VIDIOC_QBUF: 00:00:00.00000000 index=1, type=vid-cap, flags=0x00002002, field=any, sequence=0, memory=userptr, bytesused=0, offset/userptr=0x7ff2b023ca80, length=5765760 [ 9083.793028] timecode=00:00:00 type=0, flags=0x00000000, frames=0, userbits=0x00000000 [ 9083.793117] video0: VIDIOC_QBUF: error -22: 00:00:00.00000000 index=2, type=vid-cap, flags=0x00000000, field=any, sequence=0, memory=userptr, bytesused=0, offset/userptr=0x7ff2b07bc500, length=5765760
Also use true instead of 1 since that argument is a bool in the get_vaddr_frames() prototype.
Fixes: 21fb0cb7ec65 ("[media] vb2: Provide helpers for mapping virtual addresses")
Reported-by: Albert Antony <albert@newtec.dk> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> [hans.verkuil@cisco.com: merged the 'bool' change into this patch] Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
--- drivers/media/v4l2-core/videobuf2-memops.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/media/v4l2-core/videobuf2-memops.c +++ b/drivers/media/v4l2-core/videobuf2-memops.c @@ -49,7 +49,7 @@ struct frame_vector *vb2_create_framevec vec = frame_vector_create(nr); if (!vec) return ERR_PTR(-ENOMEM); - ret = get_vaddr_frames(start, nr, write, 1, vec); + ret = get_vaddr_frames(start & PAGE_MASK, nr, write, true, vec); if (ret < 0) goto out_destroy; /* We accept only complete set of PFNs */
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