Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   ebiederm@xmission.com (Eric W. Biederman)
To:     Kees Cook <keescook@chromium.org>
Cc:     Andrea Righi <andrea.righi@canonical.com>,
        Shuah Khan <shuah@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Will Drewry <wad@chromium.org>,
        linux-kselftest@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
References: <YXrN+Hnl9pSOsWlA@arighi-desktop> <202110280955.B18CB67@keescook>
        <878rydm56l.fsf@disp2133> <202110281136.5CE65399A7@keescook>
        <8735okls76.fsf@disp2133> <202110290755.451B036CE9@keescook>
        <87y2665sf8.fsf@disp2133> <202111030838.CB201E4@keescook>
Date:   Wed, 03 Nov 2021 13:35:56 -0500
In-Reply-To: <202111030838.CB201E4@keescook> (Kees Cook's message of "Wed, 3
        Nov 2021 09:14:47 -0700")
Message-ID: <87v9193x4j.fsf@disp2133>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Subject: Re: selftests: seccomp_bpf failure on 5.15
Precedence: bulk

Kees Cook <keescook@chromium.org> writes:

> On Tue, Nov 02, 2021 at 01:22:19PM -0500, Eric W. Biederman wrote:
>> Kees Cook <keescook@chromium.org> writes:
>> 
>> > On Thu, Oct 28, 2021 at 05:06:53PM -0500, Eric W. Biederman wrote:
>> >> Kees Cook <keescook@chromium.org> writes:
>> >> 
>> >> > On Thu, Oct 28, 2021 at 12:26:26PM -0500, Eric W. Biederman wrote:
>> >> 
>> >> Is it a problem that the debugger can see the signal if the process does
>> >> not?
>> >
>> > Right, I'm trying to understand that too. However, my neighbor just lost
>> > power. :|
>> >
>> > What I was in the middle of checking was what ptrace "sees" going
>> > through a fatal SIGSYS; my initial debugging attempts were weird.
>> 
>> Kees have you regained power and had a chance to see my SA_IMMUTABLE
>> patch?
>
> Apologies; I got busy with other stuff, but I've tested this now. It's
> happy and I see the expected behaviors again. Note that I used the patch
> with this change:
>
> -#define SA_IMMUTABLE           0x008000000
> +#define SA_IMMUTABLE           0x00800000
>
> Tested-by: Kees Cook <keescook@chromium.org>

Thanks.

And I see you have written a test as well that should keep
this kind of bug from happening again.

Eric