From 5ed7f4b5eca11c3c69e7c8b53e4321812bc1ee1e Mon Sep 17 00:00:00 2001 From: Murray McAllister Date: Mon, 20 May 2019 21:57:34 +1200 Subject: [PATCH] drm/vmwgfx: integer underflow in vmw_cmd_dx_set_shader() leading to an invalid read If SVGA_3D_CMD_DX_SET_SHADER is called with a shader ID of SVGA3D_INVALID_ID, and a shader type of SVGA3D_SHADERTYPE_INVALID, the calculated binding.shader_slot will be 4294967295, leading to an out-of-bounds read in vmw_binding_loc() when the offset is calculated. Cc: Fixes: d80efd5cb3de ("drm/vmwgfx: Initial DX support") Signed-off-by: Murray McAllister Reviewed-by: Thomas Hellstrom Signed-off-by: Thomas Hellstrom --- drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c index b4c7553d2814..33533d126277 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c @@ -2206,7 +2206,8 @@ static int vmw_cmd_dx_set_shader(struct vmw_private *dev_priv, cmd = container_of(header, typeof(*cmd), header); - if (cmd->body.type >= SVGA3D_SHADERTYPE_DX10_MAX) { + if (cmd->body.type >= SVGA3D_SHADERTYPE_DX10_MAX || + cmd->body.type < SVGA3D_SHADERTYPE_MIN) { VMW_DEBUG_USER("Illegal shader type %u.\n", (unsigned int) cmd->body.type); return -EINVAL;