Commit 9f1a693f authored Mar 08, 2009 by Hans Verkuil Committed by Mauro Carvalho Chehab Mar 30, 2009

V4L/DVB (10920): v4l2-ioctl: fix partial-copy code.



The code to optimize the usercopy only checked the ioctl NR field. However,
this code is also called for non-V4L2 ioctls (either private or ioctls from
linux/dvb/audio.h and linux/dvb/video.h for decoder drivers like ivtv).

If such an ioctl has the same NR as a V4L2 ioctl, then disaster strikes.

Modified the code to check on the full command ID.

Thanks to Martin Dauskardt for tracing the ivtv breakage to this particular
change.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

parent 501cd11a

drivers/media/video/v4l2-ioctl.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -1796,11 +1796,12 @@ static long __video_do_ioctl(struct file *file,
		static unsigned long cmd_input_size(unsigned int cmd)
		{
		/* Size of structure up to and including 'field' */
		#define CMDINSIZE(cmd, type, field) case _IOC_NR(VIDIOC_##cmd): return \
		offsetof(struct v4l2_##type, field) + \
		#define CMDINSIZE(cmd, type, field) \
		case VIDIOC_##cmd: \
		return offsetof(struct v4l2_##type, field) + \
		sizeof(((struct v4l2_##type *)0)->field);

		switch (_IOC_NR(cmd)) {
		switch (cmd) {
		CMDINSIZE(ENUM_FMT, fmtdesc, type);
		CMDINSIZE(G_FMT, format, type);
		CMDINSIZE(QUERYBUF, buffer, type);