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From:   Florent Revest <revest@chromium.org>
Date:   Tue, 4 Jul 2023 17:45:53 +0200
Message-ID: <CABRcYmJgOAFMO2Uuyn1sdoTLk1PXrxuqo4Hwkg6UkSDgMOvnYg@mail.gmail.com>
Subject: Re: [PATCH v3 3/5] mm: Make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long
To:     linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc:     akpm@linux-foundation.org, catalin.marinas@arm.com,
        anshuman.khandual@arm.com, joey.gouly@arm.com, mhocko@suse.com,
        keescook@chromium.org, david@redhat.com, peterx@redhat.com,
        izbyshev@ispras.ru, broonie@kernel.org, szabolcs.nagy@arm.com,
        kpsingh@kernel.org, gthelen@google.com, toiwoton@gmail.com,
        linux-stable@vger.kernel.org
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On Tue, Jul 4, 2023 at 5:37=E2=80=AFPM Florent Revest <revest@chromium.org>=
 wrote:
>
> Defining a prctl flag as an int is a footgun because on a 64 bit machine
> and with a variadic implementation of prctl (like in musl and glibc),
> when used directly as a prctl argument, it can get casted to long with
> garbage upper bits which would result in unexpected behaviors.
>
> This patch changes the constant to an unsigned long to eliminate that
> possibilities. This does not break UAPI.
>
> Fixes: b507808ebce2 ("mm: implement memory-deny-write-execute as a prctl"=
)
> Cc: linux-stable@vger.kernel.org

Oops, this was supposed to be stable@vger.kernel.org... I'll fix that
tag as part of v4.