[PATCH] drm/nouveau: check ioctl command codes better

[Arnd Bergmann]

From: Arnd Bergmann <a...@arndb.de>

nouveau_drm_ioctl() only checks the _IOC_NR() bits in the DRM_NOUVEAU_NVIF
command, but ignores the type and direction bits, so any command with
'7' in the low eight bits gets passed into nouveau_abi16_ioctl() instead
of drm_ioctl().

Check for all the bits except the size that is handled inside of the handler.

Fixes: 27111a23d01c ("drm/nouveau: expose the full object/event interfaces to 
userspace")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 drivers/gpu/drm/nouveau/nouveau_drm.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c 
b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 1527b801f013..506eeb44f0d4 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -1284,6 +1284,9 @@ nouveau_ioctls[] = {
        DRM_IOCTL_DEF_DRV(NOUVEAU_EXEC, nouveau_exec_ioctl_exec, 
DRM_RENDER_ALLOW),
 };
 
+#define DRM_IOCTL_NOUVEAU_NVIV _IOC(_IOC_READ|_IOC_WRITE, DRM_IOCTL_BASE, \
+                                   DRM_COMMAND_BASE + DRM_NOUVEAU_NVIF, 0)
+
 long
 nouveau_drm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
@@ -1297,14 +1300,10 @@ nouveau_drm_ioctl(struct file *file, unsigned int cmd, 
unsigned long arg)
                return ret;
        }
 
-       switch (_IOC_NR(cmd) - DRM_COMMAND_BASE) {
-       case DRM_NOUVEAU_NVIF:
+       if ((cmd & ~IOCSIZE_MASK) == DRM_IOCTL_NOUVEAU_NVIV)
                ret = nouveau_abi16_ioctl(filp, (void __user *)arg, 
_IOC_SIZE(cmd));
-               break;
-       default:
+       else
                ret = drm_ioctl(file, cmd, arg);
-               break;
-       }
 
        pm_runtime_mark_last_busy(dev->dev);
        pm_runtime_put_autosuspend(dev->dev);
-- 
2.39.5