linux-kernel - Re: [PATCH] mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios

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: <4e408146-7c77-4f6d-90e8-bb311d7ab53d@126.com>
Date: Fri, 23 May 2025 11:46:51 +0800
From: Ge Yang <yangge1116@....com>
To: Muchun Song <muchun.song@...ux.dev>, Oscar Salvador <osalvador@...e.de>
Cc: akpm@...ux-foundation.org, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org, stable@...r.kernel.org, 21cnbao@...il.com,
 david@...hat.com, baolin.wang@...ux.alibaba.com, liuzixing@...on.cn
Subject: Re: [PATCH] mm/hugetlb: fix kernel NULL pointer dereference when
 replacing free hugetlb folios



在 2025/5/23 11:27, Muchun Song 写道:
> 
> 
>> On May 23, 2025, at 03:32, Oscar Salvador <osalvador@...e.de> wrote:
>>
>> On Thu, May 22, 2025 at 08:39:39PM +0800, Muchun Song wrote:
>>> But I think we could use "folio_order() > MAX_PAGE_ORDER" to replace the check
>>> of hstate_is_gigantic(), right? Then ee could remove the first parameter of hstate
>>> from alloc_and_dissolve_hugetlb_folio() and obtain hstate in it.
>>
>> Yes, I think we can do that.
>> So something like the following (compily-tested only) maybe?
>>
>>  From d7199339e905f83b54d22849e8f21f631916ce94 Mon Sep 17 00:00:00 2001
>> From: Oscar Salvador <osalvador@...e.de>
>> Date: Thu, 22 May 2025 19:51:04 +0200
>> Subject: [PATCH] TMP
>>
>> ---
>>   mm/hugetlb.c | 38 +++++++++-----------------------------
>>   1 file changed, 9 insertions(+), 29 deletions(-)
> 
> Pretty simple. The code LGTM.
> 
> Thanks.

Thanks.

The implementation of alloc_and_dissolve_hugetlb_folio differs between 
kernel 6.6 and kernel 6.15. To facilitate backporting, I'm planning to 
submit another patch based on Oscar Salvador's suggestion.