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From:   Thomas Gleixner <tglx@linutronix.de>
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To:     Song Liu <songliubraving@meta.com>
Cc:     Song Liu <song@kernel.org>,
        "linux-modules@vger.kernel.org" <linux-modules@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Christoph Hellwig <hch@lst.de>,
        Kernel Team <kernel-team@meta.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Guenter Roeck <linux@roeck-us.net>,
        Christophe Leroy <christophe.leroy@csgroup.eu>
Subject: Re: [PATCH v9] module: replace module_layout with module_memory
In-Reply-To: <09C6F0A2-5AE5-4D8D-87DE-BFEC2C642A49@fb.com>
References: <20230203214500.745276-1-song@kernel.org> <87cz6mxyb7.ffs@tglx>
 <09C6F0A2-5AE5-4D8D-87DE-BFEC2C642A49@fb.com>
Date:   Tue, 07 Feb 2023 11:13:32 +0100
Message-ID: <87edr1wzoz.ffs@tglx>
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On Mon, Feb 06 2023 at 23:27, Song Liu wrote:
>> On Feb 6, 2023, at 1:45 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
>>> +static void free_mod_mem(struct module *mod)
>>> +{
>>> + /* free the memory in the right order to avoid use-after-free */
>> 
>> How do we end up with a UAF when the ordering is different?
>
> IIUC, we need remove MOD_DATA at last, which hosts "mod".

Oh. Please add a comment to that effect.

Thanks,

        tglx