drm: drm_ioctl() should zero-init extra data

If an older userspace passes in a smaller arg than the current kernel ioctl arg struct, then extra fields should be initialized to zero rather than passing random data to the DRM driver. Signed-off-by: Rob Clark <rob@ti.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
git-mirror · Oct 19, 2011 · dd2351d · dd2351d
1 parent 017ed80
commit dd2351d
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
@@ -438,6 +438,8 @@ long drm_ioctl(struct file *filp,
 					goto err_i1;
 				}
 			}
+			if (asize > usize)
+				memset(kdata + usize, 0, asize - usize);
 		}
 
 		if (cmd & IOC_IN) {