Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) client-ip=2620:137:e000::3:4;
Date:   Tue, 10 Oct 2023 17:26:16 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Hengqi Chen <hengqi.chen@gmail.com>
Cc:     linux-kernel@vger.kernel.org, bpf@vger.kernel.org, ast@kernel.org,
        daniel@iogearbox.net, andrii@kernel.org, luto@amacapital.net,
        wad@chromium.org, alexyonghe@tencent.com
Subject: Re: [PATCH 4/4] selftests/seccomp: Test SECCOMP_LOAD_FILTER and
 SECCOMP_ATTACH_FILTER
Message-ID: <202310101725.0BCB9CBA9@keescook>
References: <20231009124046.74710-1-hengqi.chen@gmail.com>
 <20231009124046.74710-5-hengqi.chen@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20231009124046.74710-5-hengqi.chen@gmail.com>
Precedence: bulk

On Mon, Oct 09, 2023 at 12:40:46PM +0000, Hengqi Chen wrote:
> Add a testcase to exercise the newly added SECCOMP_LOAD_FILTER
> and SECCOMP_ATTACH_FILTER operations.
> 
> Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
> ---
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 20 +++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
> index 38f651469968..8f7010482194 100644
> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
> @@ -4735,6 +4735,26 @@ TEST(user_notification_wait_killable_fatal)
>  	EXPECT_EQ(SIGTERM, WTERMSIG(status));
>  }
>  
> +TEST(seccomp_filter_load_and_attach)
> +{
> +	struct sock_filter filter[] = {
> +		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
> +	};
> +	struct sock_fprog prog = {
> +		.len = (unsigned short)ARRAY_SIZE(filter),
> +		.filter = filter,
> +	};
> +	int fd, ret;
> +
> +	fd = seccomp(SECCOMP_LOAD_FILTER, 0, &prog);
> +	ASSERT_GT(fd, -1);
> +
> +	ret = seccomp(SECCOMP_ATTACH_FILTER, 0, &fd);
> +	ASSERT_EQ(ret, 0);
> +
> +	close(fd);
> +}

This is a good start -- please check all the error paths as well.

Thanks for continuing to work on this!

-- 
Kees Cook