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Date:   Tue, 25 Jan 2022 18:25:50 -0800
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Yury Norov <yury.norov@gmail.com>
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Ding Tianhong <dingtianhong@huawei.com>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Matthew Wilcox <willy@infradead.org>,
        Alexey Klimov <aklimov@redhat.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH v2] vmap(): don't allow invalid pages
Message-Id: <20220125182550.7c693c76fe6520047c2e4f26@linux-foundation.org>
In-Reply-To: <20220119012109.551931-1-yury.norov@gmail.com>
References: <20220119012109.551931-1-yury.norov@gmail.com>
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On Tue, 18 Jan 2022 17:21:09 -0800 Yury Norov <yury.norov@gmail.com> wrote:

> vmap() takes struct page *pages as one of arguments, and user may provide
> an invalid pointer which would lead to data abort at address translation
> later.

Does "user" mean userspace code?

If so, please tell us much more about the means by which userspace can
trigger this problem.