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>
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 93a112d..7a87e08 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -438,6 +438,8 @@
goto err_i1;
}
}
+ if (asize > usize)
+ memset(kdata + usize, 0, asize - usize);
}
if (cmd & IOC_IN) {