Correctly set the length of the drm_event to the size of the structure that's actually used.
The length of the drm_event was set to the parent structure instead of to the drm_vmw_event_fence which is supposed to be read. drm_read uses the length parameter to copy the event to the user space thus resuling in oob reads. Signed-off-by: Zack Rusin <[email protected]> Fixes: 8b7de6aa8468 ("vmwgfx: Rework fence event action") Reported-by: [email protected] # ZDI-CAN-23566 Cc: David Airlie <[email protected]> CC: Daniel Vetter <[email protected]> Cc: Zack Rusin <[email protected]> Cc: Broadcom internal kernel review list <[email protected]> Cc: [email protected] Cc: [email protected] Cc: <[email protected]> # v3.4+ --- drivers/gpu/drm/vmwgfx/vmwgfx_fence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c index 2a0cda324703..5efc6a766f64 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c @@ -991,7 +991,7 @@ static int vmw_event_fence_action_create(struct drm_file *file_priv, } event->event.base.type = DRM_VMW_EVENT_FENCE_SIGNALED; - event->event.base.length = sizeof(*event); + event->event.base.length = sizeof(event->event); event->event.user_data = user_data; ret = drm_event_reserve_init(dev, file_priv, &event->base, &event->event.base); -- 2.40.1
