linux-kernel - Re: [PATCH 4/4] mm/gup: Assert that the mmap lock is held in __get_user

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] [day] [month] [year] [list]

Message-ID: <CANN689HPPP3kKNFpm5ymJhk-FODN1nXgMHouZ5-v1m=BJ+HyJg@mail.gmail.com>
Date:   Wed, 30 Sep 2020 16:24:39 -0700
From:   Michel Lespinasse <walken@...gle.com>
To:     Jason Gunthorpe <jgg@...pe.ca>
Cc:     Jann Horn <jannh@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-mm <linux-mm@...ck.org>,
        LKML <linux-kernel@...r.kernel.org>,
        "Eric W . Biederman" <ebiederm@...ssion.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>
Subject: Re: [PATCH 4/4] mm/gup: Assert that the mmap lock is held in __get_user_pages()

On Wed, Sep 30, 2020 at 5:32 AM Jason Gunthorpe <jgg@...pe.ca> wrote:
> On Tue, Sep 29, 2020 at 06:20:01PM -0700, Jann Horn wrote:
> > After having cleaned up all GUP callers (except for the atomisp staging
> > driver, which currently gets mmap locking completely wrong [1]) to always
> > ensure that they hold the mmap lock when calling into GUP (unless the mm is
> > not yet globally visible), add an assertion to make sure it stays that way
> > going forward.

Thanks for doing this, there is a lot of value in ensuring that a
function's callers follows the prerequisites.

Acked-by: Michel Lespinasse <walken@...gle.com>