From: Muchun Song <muchun.song@linux.dev>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Muchun Song <songmuchun@bytedance.com>,
glider@google.com, elver@google.com, dvyukov@google.com,
jannh@google.com, sjpark@amazon.de, kasan-dev@googlegroups.com,
Linux Memory Management List <linux-mm@kvack.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: kfence: fix handling discontiguous page
Date: Fri, 24 Mar 2023 09:59:16 +0800 [thread overview]
Message-ID: <FEB74A1F-9DA2-4B37-8AD5-5E41A399046C@linux.dev> (raw)
In-Reply-To: <20230323151850.e2785b1cff37fba078f26f2b@linux-foundation.org>
> On Mar 24, 2023, at 06:18, Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Thu, 23 Mar 2023 10:50:03 +0800 Muchun Song <songmuchun@bytedance.com> wrote:
>
>> The struct pages could be discontiguous when the kfence pool is allocated
>> via alloc_contig_pages() with CONFIG_SPARSEMEM and !CONFIG_SPARSEMEM_VMEMMAP.
>> So, the iteration should use nth_page().
>
> What are the user-visible runtime effects of this flaw?
Set the PG_slab and memcg_data to a arbitrary address (may be not used as a struct
page), so the worst case may corrupt the kernel.
Thanks.
>
> Thanks.
next prev parent reply other threads:[~2023-03-24 1:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-23 2:50 Muchun Song
2023-03-23 8:28 ` Marco Elver
2023-03-23 22:18 ` Andrew Morton
2023-03-24 1:59 ` Muchun Song [this message]
2023-03-24 3:43 ` Kefeng Wang
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