From e4fda9f264e154946c678ca7ff07023f573abf6a Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 12 Apr 2013 10:39:59 +0100 Subject: [PATCH] drm: Perform ioctl command validation on the stored kernel values Userspace is free to pass in any command bits it feels like through the ioctl cmd, and for example trinity likes to fuzz those bits to create conflicting commands. So instead of relying upon userspace to pass along the correct IN/OUT flags for the ioctl, use the flags as expected by the kernel. This does have a side-effect that NULL pointers can not be substituted by userspace in place of a struct. This feature was not being used by any driver, but instead exposed all of the command handlers to a user triggerable OOPS. Reported-by: Tommi Rantala Link: http://lkml.kernel.org/r/CA+ydwtpuBvbwxbt-tdgPUvj1EU7itmCHo_2B3w13HkD5+jWKow@mail.gmail.com Signed-off-by: Tommi Rantala Signed-off-by: Chris Wilson Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_drv.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 25f91cd23e60..0ac1991a470a 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -408,6 +408,7 @@ long drm_ioctl(struct file *filp, usize = asize = _IOC_SIZE(cmd); if (drv_size > asize) asize = drv_size; + cmd = ioctl->cmd_drv; } else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) { ioctl = &drm_ioctls[nr];