From a37ef7613c00f2d72c8fc08bd83fb6cc76926c8c Mon Sep 17 00:00:00 2001 From: Zack Rusin Date: Thu, 25 Apr 2024 15:27:48 -0400 Subject: [PATCH] drm/vmwgfx: Fix invalid reads in fence signaled events 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 Fixes: 8b7de6aa8468 ("vmwgfx: Rework fence event action") Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-23566 Cc: David Airlie CC: Daniel Vetter Cc: Zack Rusin Cc: Broadcom internal kernel review list Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Cc: # v3.4+ Reviewed-by: Maaz Mombasawala Reviewed-by: Martin Krastev Link: https://patchwork.freedesktop.org/patch/msgid/20240425192748.1761522-1-zack.rusin@broadcom.com --- 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); -- 2.42.0