linux-kernel - Re: [PATCH v1] mm/gup: disallow FOLL_FORCE|FOLL

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]

Date:   Mon, 31 Oct 2022 13:14:51 -0300
From:   Jason Gunthorpe <jgg@...dia.com>
To:     David Hildenbrand <david@...hat.com>
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Peter Xu <peterx@...hat.com>,
        John Hubbard <jhubbard@...dia.com>,
        syzbot+f0b97304ef90f0d0b1dc@...kaller.appspotmail.com
Subject: Re: [PATCH v1] mm/gup: disallow FOLL_FORCE|FOLL_WRITE on hugetlb
 mappings

On Mon, Oct 31, 2022 at 04:25:24PM +0100, David Hildenbrand wrote:
> Cc: Andrew Morton <akpm@...ux-foundation.org>
> Cc: Mike Kravetz <mike.kravetz@...cle.com>
> Cc: Peter Xu <peterx@...hat.com>
> Cc: John Hubbard <jhubbard@...dia.com>
> Cc: Jason Gunthorpe <jgg@...dia.com>
> Reported-by: syzbot+f0b97304ef90f0d0b1dc@...kaller.appspotmail.com
> Signed-off-by: David Hildenbrand <david@...hat.com>
> ---
> 
> I assume this has been broken at least since 2014, when mm/gup.c came to
> life. I failed to come up with a suitable Fixes tag quickly.

I'm worried this would break RDMA over hugetlbfs maps - which is a
real thing people do.

MikeK do you have test cases?

Jason