[igt-dev] [PATCH i-g-t] tests/core_unauth_vs_render: new test for the relaxed DRM_AUTH handling

[Petri Latvala]

Just drive-by spellchecking:


On Mon, Jan 14, 2019 at 08:39:37AM +0000, Emil Velikov wrote:
> From: Emil Velikov <emil.velikov at collabora.com>
> 
> As the inline comment says, this test checks that the kernel allows
> unauthenticated master with render capable, RENDER_ALLOW ioctls.
> 
> The kernel commit has extra details why.
> 
> Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
> ---
>  tests/core_unauth_vs_render.c | 108 ++++++++++++++++++++++++++++++++++
>  tests/meson.build             |   1 +
>  2 files changed, 109 insertions(+)
>  create mode 100644 tests/core_unauth_vs_render.c
> 
> diff --git a/tests/core_unauth_vs_render.c b/tests/core_unauth_vs_render.c
> new file mode 100644
> index 00000000..a7d70d77
> --- /dev/null
> +++ b/tests/core_unauth_vs_render.c
> @@ -0,0 +1,108 @@
> +/*
> + * Copyright 2018 Collabora, Ltd
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *   Emil Velikov <emil.velikov at collabora.com>
> + */
> +
> +/*
> + * Testcase: Render capable, unauthenticated master doesn't throw -EACCES for
> + * DRM_RENDER_ALLOW ioctls.
> + */
> +
> +#include "igt.h"
> +#include <unistd.h>
> +#include <stdlib.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <signal.h>
> +#include <fcntl.h>
> +#include <inttypes.h>
> +#include <errno.h>
> +#include <sys/stat.h>
> +#include <sys/ioctl.h>
> +#include <sys/time.h>
> +#include <sys/poll.h>
> +#include <sys/resource.h>
> +#include "drm.h"
> +
> +IGT_TEST_DESCRIPTION("Call XXX from unauthenticated master doesn't return -EACCES.");
> +
> +static void test_unauth_vs_render(int master)
> +{
> +	int slave;
> +	int prime_fd;
> +	uint32_t handle;
> +
> +	/*
> +	 * The second open() happens without CAP_SYS_ADMIN, thus it
> +	 * will not be authenticated.
> +	 */
> +	slave = drm_open_driver(DRIVER_ANY); // XXX: relate to the master given?
> +	igt_require(slave >= 0);
> +
> +	/* Issuing the following ioctl will fail, no doubt about it. */
> +	igt_assert(drmPrimeFDToHandle(slave, prime_fd, &handle) < 0);
> +
> +	/*
> +	 * Updated kernels allow render capable, unauthenticated
> +	 * master to issue DRM_AUTH ioctls (like the above), as long as
> +	 * they are annotated as DRM_RENDER_ALLOW.
> +	 *
> +	 * Older ones throw -EACCES.
> +	 */
> +	igt_assert(errno != EACCES);
> +
> +	close(slave);
> +}
> +
> +/*
> + * By default IGT is executed as root.
> + * Thus we need to drop the priviladges so that the second open() results in a

privileges

> + * client which is not unauthenticated. Running as normal user cercumtains that.

circumvents?




-- 
Petri Latvala