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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2012-01-05 09:27:57 +0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-01-07 17:47:22 +0400 |
| commit | 6c06108be53ca5e94d8b0e93883d534dd9079646 (patch) | |
| tree | 2b2902e6b1c0d91f4fedd804af47ff33dbae42e1 | |
| parent | e82db75d06ac331ae39b07f57539df3c51d19b94 (diff) | |
| download | linux-6c06108be53ca5e94d8b0e93883d534dd9079646.tar.xz | |
[media] V4L/DVB: v4l2-ioctl: integer overflow in video_usercopy()
If ctrls->count is too high the multiplication could overflow and
array_size would be lower than expected. Mauro and Hans Verkuil
suggested that we cap it at 1024. That comes from the maximum
number of controls with lots of room for expantion.
$ grep V4L2_CID include/linux/videodev2.h | wc -l
211
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| -rw-r--r-- | drivers/media/video/v4l2-ioctl.c | 4 | ||||
| -rw-r--r-- | include/linux/videodev2.h | 1 |
2 files changed, 5 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c index e1da8fc9dd2f..639abeee3392 100644 --- a/drivers/media/video/v4l2-ioctl.c +++ b/drivers/media/video/v4l2-ioctl.c @@ -2226,6 +2226,10 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size, struct v4l2_ext_controls *ctrls = parg; if (ctrls->count != 0) { + if (ctrls->count > V4L2_CID_MAX_CTRLS) { + ret = -EINVAL; + break; + } *user_ptr = (void __user *)ctrls->controls; *kernel_ptr = (void *)&ctrls->controls; *array_size = sizeof(struct v4l2_ext_control) diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index 6bfaa767a817..b2e1331ca76b 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -1132,6 +1132,7 @@ struct v4l2_querymenu { #define V4L2_CTRL_FLAG_NEXT_CTRL 0x80000000 /* User-class control IDs defined by V4L2 */ +#define V4L2_CID_MAX_CTRLS 1024 #define V4L2_CID_BASE (V4L2_CTRL_CLASS_USER | 0x900) #define V4L2_CID_USER_BASE V4L2_CID_BASE /* IDs reserved for driver specific controls */ |