From: Murray McAllister <murray.mcallister@xxxxxxxxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 36274ab8c596f1240c606bb514da329add2a1bcd upstream. Before memory allocations vmw_surface_define_ioctl() checks the upper-bounds of a user-supplied size, but does not check if the supplied size is 0. Add check to avoid NULL pointer dereferences. Signed-off-by: Murray McAllister <murray.mcallister@xxxxxxxxxxxxxxx> Reviewed-by: Sinclair Yeh <syeh@xxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index 582814339748..a518493836a0 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -680,8 +680,8 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data, for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i) num_sizes += req->mip_levels[i]; - if (num_sizes > DRM_VMW_MAX_SURFACE_FACES * - DRM_VMW_MAX_MIP_LEVELS) + if (num_sizes > DRM_VMW_MAX_SURFACE_FACES * DRM_VMW_MAX_MIP_LEVELS || + num_sizes == 0) return -EINVAL; size = vmw_user_surface_size + 128 + -- 2.12.2