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From:   Jann Horn <jannh@google.com>
Date:   Thu, 10 Sep 2020 22:27:35 +0200
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Subject: Re: [RFC PATCH 3/6] security/fbfam: Use the api to manage statistics
To:     Kees Cook <keescook@chromium.org>
Cc:     Kernel Hardening <kernel-hardening@lists.openwall.com>,
        John Wood <john.wood@gmx.com>,
        Matthew Wilcox <willy@infradead.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Iurii Zaikin <yzaikin@google.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>, linux-doc@vger.kernel.org,
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On Thu, Sep 10, 2020 at 10:21 PM Kees Cook <keescook@chromium.org> wrote:
> Use the previous defined api to manage statistics calling it accordingly
> when a task forks, calls execve or exits.

You defined functions that return error codes in the previous patch,
but here you ignore the return values. That's a bad idea.

You should probably check the return value in execve() (and fail the
execution in the case where memory allocation fails), and make it so
that the other functions always succeed.