The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5ed7f4b5eca11c3c69e7c8b53e4321812bc1ee1e Mon Sep 17 00:00:00 2001

From: Murray McAllister murray.mcallister@gmail.com 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: stable@vger.kernel.org Fixes: d80efd5cb3de ("drm/vmwgfx: Initial DX support") Signed-off-by: Murray McAllister murray.mcallister@gmail.com Reviewed-by: Thomas Hellstrom thellstrom@vmware.com Signed-off-by: Thomas Hellstrom thellstrom@vmware.com

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;