2.6.18 VIDIOC_ENUMSTD bug

From: Jonathan Corbet
Date: Fri Sep 22 2006 - 18:30:34 EST


The v4l2 API documentation for VIDIOC_ENUMSTD says:

To enumerate all standards applications shall begin at index
zero, incrementing by one until the driver returns EINVAL.

The actual code, however, tests the index this way:

if (index<=0 || index >= vfd->tvnormsize) {
ret=-EINVAL;

So any application which passes in index=0 gets EINVAL right off the bat
- and, in fact, this is what happens to mplayer. So I think the
following patch is called for, and maybe even appropriate for a 2.6.18.x
stable release. Disagreement?

jon

Signed-off-by: Jonathan Corbet <corbet@xxxxxxx>

--- /k/t/2.6.18-vanilla/drivers/media/video/videodev.c 2006-09-22 16:20:56.000000000 -0600
+++ 18-mont/drivers/media/video/videodev.c 2006-09-22 14:34:14.000000000 -0600
@@ -836,7 +836,7 @@ static int __video_do_ioctl(struct inode
break;
}

- if (index<=0 || index >= vfd->tvnormsize) {
+ if (index < 0 || index >= vfd->tvnormsize) {
ret=-EINVAL;
break;
}

-
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