linux-kernel - Re: [PATCH RFC 1/1] mm/ksm: Add recovery mechanism for memory failures

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <55370eb6-9798-0f46-2301-d5f66528411b@huawei.com>
Date: Sat, 11 Oct 2025 17:23:51 +0800
From: Miaohe Lin <linmiaohe@...wei.com>
To: Lance Yang <lance.yang@...ux.dev>
CC: Longlong Xia <xialonglong2025@....com>, <nao.horiguchi@...il.com>,
	<akpm@...ux-foundation.org>, <wangkefeng.wang@...wei.com>,
	<xu.xin16@....com.cn>, <linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
	Longlong Xia <xialonglong@...inos.cn>, <david@...hat.com>
Subject: Re: [PATCH RFC 1/1] mm/ksm: Add recovery mechanism for memory
 failures

On 2025/10/11 15:52, Lance Yang wrote:
> @Miaohe
> 
> I'd like to raise a concern about a potential hardware failure :)

Thanks for your thought.

> 
> My tests show that if the shared zeropage (or huge zeropage) gets marked
> with HWpoison, the kernel continues to install it for new mappings.
> Surprisingly, it does not kill the accessing process ...

Have you investigated the cause? If user space writes to shared zeropage,
it will trigger COW and a new page will be installed. After that, reading
the newly allocated page won't trigger memory error. In this scene, it does
not kill the accessing process.

> 
> The concern is, once the page is no longer zero-filled due to the hardware
> failure, what will happen? Would this lead to silent data corruption for
> applications that expect to read zeros?

IMHO, once the page is no longer zero-filled due to the hardware failure, later
any read will trigger memory error and memory_failure should handle that.

Thanks.
.