linux-kernel - Re: [PATCH v6 3/7] x86/mm: Use 'ptdesc' when freeing PMD pages

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: <b6fdba02-cc3e-4d06-b013-fba94209e7a1@intel.com>
Date: Tue, 14 Oct 2025 16:19:55 -0700
From: Dave Hansen <dave.hansen@...el.com>
To: Lu Baolu <baolu.lu@...ux.intel.com>, Joerg Roedel <joro@...tes.org>,
 Will Deacon <will@...nel.org>, Robin Murphy <robin.murphy@....com>,
 Kevin Tian <kevin.tian@...el.com>, Jason Gunthorpe <jgg@...dia.com>,
 Jann Horn <jannh@...gle.com>, Vasant Hegde <vasant.hegde@....com>,
 Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
 Borislav Petkov <bp@...en8.de>, Alistair Popple <apopple@...dia.com>,
 Peter Zijlstra <peterz@...radead.org>, Uladzislau Rezki <urezki@...il.com>,
 Jean-Philippe Brucker <jean-philippe@...aro.org>,
 Andy Lutomirski <luto@...nel.org>, Yi Lai <yi1.lai@...el.com>,
 David Hildenbrand <david@...hat.com>,
 Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
 "Liam R . Howlett" <Liam.Howlett@...cle.com>,
 Andrew Morton <akpm@...ux-foundation.org>, Vlastimil Babka <vbabka@...e.cz>,
 Mike Rapoport <rppt@...nel.org>, Michal Hocko <mhocko@...nel.org>,
 Matthew Wilcox <willy@...radead.org>
Cc: iommu@...ts.linux.dev, security@...nel.org, x86@...nel.org,
 linux-mm@...ck.org, linux-kernel@...r.kernel.org,
 Dave Hansen <dave.hansen@...ux.intel.com>
Subject: Re: [PATCH v6 3/7] x86/mm: Use 'ptdesc' when freeing PMD pages

On 10/14/25 06:04, Lu Baolu wrote:
> -#if defined(CONFIG_SPLIT_PMD_PTLOCKS)
> -
> +#if defined(CONFIG_SPLIT_PMD_PTLOCKS) || defined(CONFIG_X86_64)

What's with the #ifdef munging? It's not mentioned in the changelog.

I went looking at this because pmd_free_pte_page() is right in the
middle of the action on this reported use after free:

> https://lore.kernel.org/all/68eeb99e.050a0220.91a22.0220.GAE@google.com/

so something fishy is going on. It would be great to narrow that report
down to a _specific_ patch in the series.