Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 30 Dec 2019 14:02:45 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Sargun Dhillon <sargun@sargun.me>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Christian Brauner <christian.brauner@ubuntu.com>,
        Aleksa Sarai <cyphar@cyphar.com>,
        Tycho Andersen <tycho@tycho.ws>
Subject: Re: [PATCH] selftests/seccomp: Test kernel catches garbage on
 SECCOMP_IOCTL_NOTIF_RECV
Message-ID: <201912301402.DAA6ED9A0@keescook>
References: <20191230203811.4996-1-sargun@sargun.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20191230203811.4996-1-sargun@sargun.me>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Dec 30, 2019 at 12:38:11PM -0800, Sargun Dhillon wrote:
> This adds to the user_notification_basic to set a field of seccomp_notif
> to an invalid value to ensure that the kernel returns EINVAL if any of the
> seccomp_notif fields are set to invalid values.
> 
> Signed-off-by: Sargun Dhillon <sargun@sargun.me>
> Suggested-by: Christian Brauner <christian.brauner@ubuntu.com>
> Cc: Kees Cook <keescook@chromium.org>

Thanks! Applied. :)

-Kees

> ---
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
> index f53f14971bff..393578a78dbc 100644
> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
> @@ -3158,6 +3158,13 @@ TEST(user_notification_basic)
>  	EXPECT_GT(poll(&pollfd, 1, -1), 0);
>  	EXPECT_EQ(pollfd.revents, POLLIN);
>  
> +	/* Test that we can't pass garbage to the kernel. */
> +	memset(&req, 0, sizeof(req));
> +	req.pid = -1;
> +	EXPECT_EQ(-1, ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req));
> +	EXPECT_EQ(EINVAL, errno);
> +
> +	req.pid = 0;
>  	EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
>  
>  	pollfd.fd = listener;
> -- 
> 2.20.1
> 

-- 
Kees Cook