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References: <20220413122925.33856-1-patrick.wang.shcn@gmail.com> <20220413122826.792a859d90b6c2822b1c796a@linux-foundation.org>
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From:   patrick wang <patrick.wang.shcn@gmail.com>
Date:   Thu, 14 Apr 2022 10:40:50 +0800
Message-ID: <CAGcnep_rWWYBr+NFYzh7wNhoenFpwbxy=15a6w5vpJAH8P1dDg@mail.gmail.com>
Subject: Re: [PATCH] mm: kmemleak: take a full lowmem check in kmemleak_*_phys()
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     catalin.marinas@arm.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
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On Thu, Apr 14, 2022 at 3:28 AM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Wed, 13 Apr 2022 20:29:25 +0800 Patrick Wang <patrick.wang.shcn@gmail.com> wrote:
>
> > The kmemleak_*_phys() apis do not check the address for lowmem's min
> > boundary, while the caller may pass an address below lowmem, which
> > will trigger an oops:
>
> Do you believe this fix should be backported into -stable kernels?

Yes, I think so. The callers may not quite know the actual address they
pass(e.g. from devicetree). So the kmemleak_*_phys() apis should guarantee
the address they finally use is in lowmem range.