linux-kernel - Re: [PATCH V2 1/2] efi/unaccepted: Do not let /proc/vmcore try to access unaccepted memory

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: <96f124d6-c1f2-adb3-1d3b-8329e85ff099@redhat.com>
Date:   Tue, 12 Sep 2023 09:19:38 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Adrian Hunter <adrian.hunter@...el.com>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Borislav Petkov <bp@...en8.de>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Ard Biesheuvel <ardb@...nel.org>
Cc:     Dave Hansen <dave.hansen@...el.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Mike Rapoport <rppt@...ux.ibm.com>,
        Lorenzo Stoakes <lstoakes@...il.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Baoquan He <bhe@...hat.com>, Vivek Goyal <vgoyal@...hat.com>,
        Dave Young <dyoung@...hat.com>, linux-kernel@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
        linux-coco@...ts.linux.dev, linux-efi@...r.kernel.org,
        kexec@...ts.infradead.org
Subject: Re: [PATCH V2 1/2] efi/unaccepted: Do not let /proc/vmcore try to
 access unaccepted memory

On 11.09.23 13:21, Adrian Hunter wrote:
> Support for unaccepted memory was added recently, refer commit dcdfdd40fa82
> ("mm: Add support for unaccepted memory"), whereby a virtual machine may
> need to accept memory before it can be used.
> 
> Do not let /proc/vmcore try to access unaccepted memory because it can
> cause the guest to fail.

Oh, hold on. What are the actual side effects of this?

Once we're in the kdump kernel, any guest is already dead. So failing a 
guest doesn't apply, no?

-- 
Cheers,

David / dhildenb