drm: fix NULL pointer access by wrong ioctl

If user uses wrong ioctl command with _IOC_NONE and argument size
greater than 0, it can cause NULL pointer access from memset of line
463. If _IOC_NONE, don't memset to 0 for kdata.

Signed-off-by: Zhaowei Yuan <zhaowei.yuan@samsung.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Zhaowei Yuan 2014-06-18 14:33:59 +08:00 committed by Dave Airlie
parent a497c3ba1d
commit 1539fb9bd4

3
drivers/gpu/drm/drm_drv.c Normal file → Executable file
View file

@ -419,8 +419,9 @@ long drm_ioctl(struct file *filp,
retcode = -EFAULT;
goto err_i1;
}
} else
} else if (cmd & IOC_OUT) {
memset(kdata, 0, usize);
}
if (ioctl->flags & DRM_UNLOCKED)
retcode = func(dev, kdata, file_priv);