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Date:   Tue, 16 Aug 2022 11:18:03 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Tuo Cao <91tuocao@gmail.com>
Cc:     mingo@redhat.com, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
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        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched: core: remove access_ok() before copy_to_user()
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On Mon, Aug 15, 2022 at 10:21:37PM +0800, Tuo Cao wrote:
> If usize > ksize, usize may be not valid and if(!access_ok()) will return
> -EFAULT. But ksize may be valid, copy_to_user() should be executed.And
> also, copy_to_user() will calls access_ok() to test whether a block of
> memory is a valid user space address.

I don't follow, why do you want this to continue if the user provided
garbage input?