Ok, only Stradis driver actually uses it. I doubt that stradis still work
nowadays, and it is not compiled on RHEL5/RHEL6. Need to check mrg. Patch is as
simple as remove the compat bits for this ioctl.
(In reply to comment #1)
> Ok, only Stradis driver actually uses it. I doubt that stradis still work
> nowadays, and it is not compiled on RHEL5/RHEL6.
Well in that case we may close this as notabug, right Eugene?
(In reply to comment #2)
> (In reply to comment #1)
> > Ok, only Stradis driver actually uses it. I doubt that stradis still work
> > nowadays, and it is not compiled on RHEL5/RHEL6.
> Well in that case we may close this as notabug, right Eugene?
No, we can't. The v4l2-compat layer is called for all V4L2 drivers. The other drivers will return an error code for a VIDIOCSMICROCODE call, but, as the bug is at compat layer, it will affect any system with a V4L hardware.
The effects are limited to machines with some V4L hardware (like a webcam or a TV capture board), so, it affects more workstations and notebooks with RHEL.
static inline int microcode32(struct video_code *kp, struct video_code32 __user *up)
if(!access_ok(VERIFY_READ, up, sizeof(struct video_code32)) ||
copy_from_user(kp->loadwhat, up->loadwhat, sizeof (up->loadwhat)) ||
get_user(kp->datasize, &up->datasize) ||
copy_from_user(kp->data, up->data, up->datasize))
$ grep compat_ioctl32 Makefile
obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-common.o compat_ioctl32.o
err = microcode32(&karg.vc, up);
compatible_arg = 0;
Even if no drivers uses it, we should just disable it.
in kernel 2.6.18-194.21.1.el5
See https://bugzilla.redhat.com/show_bug.cgi?id=642465#c8. Thanks.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.
Technical note added. If any revisions are required, please edit the "Technical Notes" field
accordingly. All revisions will be proofread by the Engineering Content Services team.
A vulnerability was discovered in the 32-bit compatibility code for the VIDIOCSMICROCODE IOCTL (Input/Output Control) in the Video4Linux implementation. It does not affect Red Hat Enterprise Linux 5, but as a preventive measure, this update removes the code. Red Hat would like to thank Kees Cook for reporting this vulnerability.