From ee9c4e681ec4f58e42a83cb0c22a0289ade1aacf Mon Sep 17 00:00:00 2001 From: Vladis Dronov Date: Fri, 2 Jun 2017 07:42:09 +0200 Subject: [PATCH] drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl() The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is a user-controlled 'uint32_t' value which is used as a loop count limit. This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'. References: https://bugzilla.redhat.com/show_bug.cgi?id=1437431 Cc: Signed-off-by: Vladis Dronov Reviewed-by: Sinclair Yeh --- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index 7681341fe32b..baf03d4d86d2 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -1279,6 +1279,9 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, void *data, if (req->multisample_count != 0) return -EINVAL; + if (req->mip_levels > DRM_VMW_MAX_MIP_LEVELS) + return -EINVAL; + if (unlikely(vmw_user_surface_size == 0)) vmw_user_surface_size = ttm_round_pot(sizeof(*user_srf)) + 128; -- 2.20.1