linux-kernel - Re: [GIT PULL] VFIO updates for v6.17-rc1

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: <20250805123858.GJ184255@nvidia.com>
Date: Tue, 5 Aug 2025 09:38:58 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: David Hildenbrand <david@...hat.com>
Cc: Alex Williamson <alex.williamson@...hat.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"lizhe.67@...edance.com" <lizhe.67@...edance.com>
Subject: Re: [GIT PULL] VFIO updates for v6.17-rc1

On Tue, Aug 05, 2025 at 02:07:49PM +0200, David Hildenbrand wrote:
> I don't see an easy way to guarantee that. E.g., populate_section_memmap
> really just does a kvmalloc_node() and
> __populate_section_memmap()->memmap_alloc() a memblock_alloc().

Well, it is really easy, if you do the kvmalloc_node and you get the
single unwanted struct page value, then call it again and free the
first one. The second call is guarenteed to not return the unwanted
value because the first call has it allocated.

Jason