Hi,
  I managed to trigger a divide by 0 in the v4l compat code
with the mem2mem test module; I suspect perhaps it shouldn't
have been returning a 0 pixel wide picture, but either way it seems
right to guard this divide by 0 in the compatibility layer.

Tested on 2.6.36 (ubuntu build, but the code in this is the same as upstream), 
but ***not tested with a real video device***.

Signed-off-by: Dr. David Alan Gilbert <li...@treblig.org>
--
diff --git a/drivers/media/video/v4l1-compat.c 
b/drivers/media/video/v4l1-compat.c
index 0c2105c..d4ac751 100644
--- a/drivers/media/video/v4l1-compat.c
+++ b/drivers/media/video/v4l1-compat.c
@@ -645,9 +645,16 @@ static noinline long v4l1_compat_get_picture(
                goto done;
        }
 
-       pict->depth   = ((fmt->fmt.pix.bytesperline << 3)
-                        + (fmt->fmt.pix.width - 1))
-                        / fmt->fmt.pix.width;
+       if (fmt->fmt.pix.width)
+       {
+               pict->depth   = ((fmt->fmt.pix.bytesperline << 3)
+                                + (fmt->fmt.pix.width - 1))
+                                / fmt->fmt.pix.width;
+       } else {
+               err = -EINVAL;
+               goto done;
+       }
+
        pict->palette = pixelformat_to_palette(
                fmt->fmt.pix.pixelformat);
 done:

-- 
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
\ gro.gilbert @ treblig.org |                               | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/
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