linux-kernel - Re: [PATCH 2/2] mm/frame-vec: use 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]

Message-ID: <20201005174747.GA15803@nvidia.com>
Date:   Mon, 5 Oct 2020 14:47:47 -0300
From:   Jason Gunthorpe <jgg@...dia.com>
To:     andrew Morton <akpm@...ux-foundation.org>,
        Daniel Vetter <daniel.vetter@...ll.ch>, <linux-mm@...ck.org>
CC:     Hans Verkuil <hans.verkuil@...co.com>, Jan Kara <jack@...e.cz>,
        "Mauro Carvalho Chehab" <mchehab@....samsung.com>,
        Mel Gorman <mgorman@...e.de>, <stable@...r.kernel.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        John Hubbard <jhubbard@...dia.com>,
        DRI Development <dri-devel@...ts.freedesktop.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
        <linux-media@...r.kernel.org>
Subject: Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM

On Mon, Oct 05, 2020 at 02:38:54PM -0300, Jason Gunthorpe wrote:
> When get_vaddr_frames() does its hacky follow_pfn() loop it should never
> be allowed to extract a struct page from a normal VMA. This could allow a
> serious use-after-free problem on any kernel memory.
> 
> Restrict this to only work on VMA's with one of VM_IO | VM_PFNMAP
> set. This limits the use-after-free problem to only IO memory, which while
> still serious, is an improvement.
> 
> Cc: stable@...r.kernel.org
> Fixes: 8025e5ddf9c1 ("[media] mm: Provide new get_vaddr_frames() helper")
> Signed-off-by: Jason Gunthorpe <jgg@...dia.com>
> ---
>  mm/frame_vector.c | 4 ++++
>  1 file changed, 4 insertions(+)

woops, this subject got badly corrupted when I was editing the CC
list, it was supposed to be:

[PATCH] mm/gpu: frame_vector: require all VMAs to be VM_PFNMAP

Andrew please let me know if you need a resend

Sorry,
Jason