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From:   Matteo Croce <mcroce@redhat.com>
Date:   Wed, 3 Apr 2019 13:54:56 +0200
Message-ID: <CAGnkfhxHhrzP7SWVQ8CCdP3yWmYrn5JQhkH1=m4_SdvacBxFTw@mail.gmail.com>
Subject: Re: [PATCH] kernel/sysctl.c: fix out of bounds access in fs.file-max
To:     linux-fsdevel@vger.kernel.org
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Christian Brauner <christian@brauner.io>,
        Matthew Wilcox <willy@infradead.org>,
        Zev Weiss <zev@bewilderbeest.net>
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On Thu, Mar 28, 2019 at 2:03 PM Matteo Croce <mcroce@redhat.com> wrote:
>
> fs.file-max sysctl uses proc_doulongvec_minmax() as proc handler, which
> accesses *extra1 and *extra2 as unsigned long, but commit 32a5ad9c2285
> ("sysctl: handle overflow for file-max") assigns &zero, which is an int,
> to extra1, generating the following KASAN report.
> Fix this by changing 'zero' to long, which does not need to be duplicated
> like 'one' and 'one_ul' for two data types.

Hi,

Anyone looked at this patch? Does my fix looks sane?

Regards,
--
Matteo Croce
per aspera ad upstream