From 7943d19453aa1a1acf93bdb2812e0bef970ec23c Mon Sep 17 00:00:00 2001 From: Vladis Dronov <vdronov@redhat.com> 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() commit ee9c4e681ec4f58e42a83cb0c22a0289ade1aacf upstream. 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 Signed-off-by: Vladis Dronov <vdronov@redhat.com> Reviewed-by: Sinclair Yeh <syeh@vmware.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- 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 67623797bd556..14551e27814c8 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -1251,6 +1251,9 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, void *data, const struct svga3d_surface_desc *desc; uint32_t backup_handle; + 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;