From:   ebiederm@xmission.com (Eric W. Biederman)
To:     Kyle Huey <me@kylehuey.com>
Cc:     open list <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        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>,
        "open list\:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        linux-hardening@vger.kernel.org,
        "Robert O'Callahan" <rocallahan@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        Oliver Sang <oliver.sang@intel.com>, lkp@lists.01.org,
        kbuild test robot <lkp@intel.com>
References: <CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com>
        <202111171049.3F9C5F1@keescook>
        <CAP045Apg9AUZN_WwDd6AwxovGjCA++mSfzrWq-mZ7kXYS+GCfA@mail.gmail.com>
        <CAP045AqjHRL=bcZeQ-O+-Yh4nS93VEW7Mu-eE2GROjhKOa-VxA@mail.gmail.com>
        <87k0h6334w.fsf@email.froward.int.ebiederm.org>
        <202111171341.41053845C3@keescook>
        <CAHk-=wgkOGmkTu18hJQaJ4mk8hGZc16=gzGMgGGOd=uwpXsdyw@mail.gmail.com>
        <CAP045ApYXxhiAfmn=fQM7_hD58T-yx724ctWFHO4UAWCD+QapQ@mail.gmail.com>
        <CAHk-=wiCRbSvUi_TnQkokLeM==_+Tow0GsQXnV3UYwhsxirPwg@mail.gmail.com>
        <CAP045AoqssLTKOqse1t1DG1HgK9h+goG8C3sqgOyOV3Wwq+LDA@mail.gmail.com>
        <202111171728.D85A4E2571@keescook>
        <87h7c9qg7p.fsf_-_@email.froward.int.ebiederm.org>
        <877dd5qfw5.fsf_-_@email.froward.int.ebiederm.org>
        <CAP045Aose7Lg_OE0-MijGBg27gWo+Sk3hbxuN3AtQ8OPC9w9+w@mail.gmail.com>
Date:   Fri, 19 Nov 2021 09:03:56 -0600
In-Reply-To: <CAP045Aose7Lg_OE0-MijGBg27gWo+Sk3hbxuN3AtQ8OPC9w9+w@mail.gmail.com>
        (Kyle Huey's message of "Thu, 18 Nov 2021 17:13:52 -0800")
Message-ID: <87r1bcp4pv.fsf@email.froward.int.ebiederm.org>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux)
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Subject: Re: [PATCH 1/2] signal: Don't always set SA_IMMUTABLE for forced signals
Precedence: bulk

Kyle Huey <me@kylehuey.com> writes:

> On Thu, Nov 18, 2021 at 2:05 PM Eric W. Biederman <ebiederm@xmission.com> wrote:
>>
>>
>> Recently to prevent issues with SECCOMP_RET_KILL and similar signals
>> being changed before they are delivered SA_IMMUTABLE was added.
>>
>> Unfortunately this broke debuggers[1][2] which reasonably expect to be
>> able to trap synchronous SIGTRAP and SIGSEGV even when the target
>> process is not configured to handle those signals.
>>
>> Update force_sig_to_task to support both the case when we can
>> allow the debugger to intercept and possibly ignore the
>> signal and the case when it is not safe to let userspace
>> known about the signal until the process has exited.
>
> s/known/know/

Fixed.


>> Reported-by: Kyle Huey <me@kylehuey.com>
>> Reported-by: kernel test robot <oliver.sang@intel.com>
>> Cc: stable@vger.kernel.org
>> [1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com
>> [2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-902
>
> This link doesn't work.

Shame.  I missed a trailing 0, but unfortunately that request did not go
to list that is archived on lore.  I will keep the link on the chance
the message winds up in a lore archive in the future.

Eric