Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
MIME-Version: 1.0
References: <20220326094654.2361956-1-yang.yang29@zte.com.cn>
 <CAHC9VhTaCNqfTOi8X5G3AheBFzTYCzGnt_-=fNFc5Z1o8gPm9Q@mail.gmail.com>
 <62465bf3.1c69fb81.d5424.365e@mx.google.com> <2777189.mvXUDI8C0e@x2>
In-Reply-To: <2777189.mvXUDI8C0e@x2>
From:   Paul Moore <paul@paul-moore.com>
Date:   Fri, 1 Apr 2022 10:16:45 -0400
Message-ID: <CAHC9VhRYHhHPx42BKa0gp974uzwHoXZWqmwt9o=1rox7tHyy1w@mail.gmail.com>
Subject: Re: [PATCH] audit: do a quick exit when syscall number is invalid
To:     Steve Grubb <sgrubb@redhat.com>
Cc:     linux-audit@redhat.com, CGEL <cgel.zte@gmail.com>,
        kbuild-all@lists.01.org, Zeal Robot <zealci@zte.com.cn>,
        linux-kernel@vger.kernel.org, eparis@redhat.com,
        dai.shixin@zte.com.cn, Yang Yang <yang.yang29@zte.com.cn>,
        ink@jurassic.park.msu.ru, huang.junhua@zte.com.cn,
        guo.xiaofeng@zte.com.cn, mattst88@gmail.com
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Fri, Apr 1, 2022 at 9:39 AM Steve Grubb <sgrubb@redhat.com> wrote:
>
> On Thursday, March 31, 2022 9:57:05 PM EDT CGEL wrote:
> > On Thu, Mar 31, 2022 at 10:16:23AM -0400, Paul Moore wrote:
> > > On Wed, Mar 30, 2022 at 10:29 PM CGEL <cgel.zte@gmail.com> wrote:
> > > > On Wed, Mar 30, 2022 at 10:48:12AM -0400, Paul Moore wrote:
> > > > > If audit is not generating SYSCALL records, even for invalid/ENOSYS
> > > > > syscalls, I would consider that a bug which should be fixed.
> > > >
> > > > If we fix this bug, do you think audit invalid/ENOSYS syscalls better
> > > > be forcible or be a rule that can be configure? I think configure is
> > > > better.
> > >
> > > It isn't clear to me exactly what you are asking, but I would expect
> > > the existing audit syscall filtering mechanism to work regardless if
> > > the syscall is valid or not.
> >
> > Thanks, I try to make it more clear. We found that auditctl would only
> > set rule with syscall number (>=0 && <2047) ...

That is exactly why I wrote the warning below in my response ...

> > > Beware that there are some limitations
> > > to the audit syscall filter, which are unfortunately baked into the
> > > current design/implementation, which may affect this to some extent.

-- 
paul-moore.com