From: Mike Rapoport <rppt@linux.ibm.com>
To: David Hildenbrand <david@redhat.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
George Kennedy <george.kennedy@oracle.com>,
Robert Moore <robert.moore@intel.com>,
Erik Kaneda <erik.kaneda@intel.com>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Len Brown <lenb@kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
"open list:ACPI COMPONENT ARCHITECTURE (ACPICA)"
<devel@acpica.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
Dhaval Giani <dhaval.giani@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Oscar Salvador <osalvador@suse.de>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
Pankaj Gupta <pankaj.gupta.linux@gmail.com>,
Michal Hocko <mhocko@suse.com>
Subject: Re: [PATCH 1/1] ACPI: fix acpi table use after free
Date: Wed, 10 Mar 2021 21:38:39 +0200 [thread overview]
Message-ID: <YEkgP0G94uQBGDa9@linux.ibm.com> (raw)
In-Reply-To: <e8593eae-40b8-bc9a-78db-529d28d2be88@redhat.com>
On Wed, Mar 10, 2021 at 08:10:42PM +0100, David Hildenbrand wrote:
>
> > > > Memory gets allocated and used in a different order, which seems to have
> > > > exposed (yet another) latent BUG.
> > >
> > > Well, you can call it that, or you can say that things worked under
> > > certain assumptions regarding the memory allocation order which are
> > > not met any more.
Regardless of the assumptions in the page allocator we had a page used by
the firmware on a free list, which is a bug.
> > > > The same could be reproduced via zone shuffling with a little luck.
> > >
> > > But nobody does that in practice.
> > >
>
> Dan will most certainly object. And I don't know what makes you speak in
> absolute words here.
>
> > > This would be relatively straightforward to address if ACPICA was not
> > > involved in it, but unfortunately that's not the case.
> > >
> > > Changing this part of ACPICA is risky, because such changes may affect
> > > other OSes using it, so that requires some serious consideration.
> > > Alternatively, the previous memory allocation order in Linux could be
> > > restored.
> >
> > Of course, long-term this needs to be addressed in the ACPI
> > initialization code, because it clearly is not robust enough, but in
> > the meantime there's practical breakage observable in the field, so
> > what can be done about that?
>
> *joke* enable zone shuffling.
>
> No seriously, fix the latent BUG. What again is problematic about excluding
> these pages from the page allcoator, for example, via memblock_reserve()?
>
> @Mike?
There is some care that should be taken to make sure we get the order
right, but I don't see a fundamental issue here.
If I understand correctly, Rafael's concern is about changing the parts of
ACPICA that should be OS agnostic, so I think we just need another place to
call memblock_reserve() rather than acpi_tb_install_table_with_override().
Since the reservation should be done early in x86::setup_arch() (and
probably in arm64::setup_arch()) we might just have a function that parses
table headers and reserves them, similarly to how we parse the tables
during KASLR setup.
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2021-03-10 19:41 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-03 20:09 [PATCH 1/1] ACPI: fix acpi table use after free George Kennedy
2021-03-04 12:14 ` Rafael J. Wysocki
2021-03-04 23:14 ` George Kennedy
2021-03-05 13:30 ` Rafael J. Wysocki
2021-03-05 13:40 ` David Hildenbrand
2021-03-05 15:24 ` George Kennedy
2021-03-10 18:39 ` Rafael J. Wysocki
2021-03-10 18:54 ` Rafael J. Wysocki
2021-03-10 19:10 ` David Hildenbrand
2021-03-10 19:38 ` Mike Rapoport [this message]
2021-03-10 19:47 ` David Hildenbrand
2021-03-11 15:36 ` Rafael J. Wysocki
2021-03-14 18:59 ` Mike Rapoport
2021-03-15 16:19 ` Rafael J. Wysocki
2021-03-15 18:05 ` Rafael J. Wysocki
2021-03-17 20:14 ` Rafael J. Wysocki
2021-03-17 22:28 ` George Kennedy
2021-03-18 15:42 ` Rafael J. Wysocki
2021-03-18 7:25 ` Mike Rapoport
2021-03-18 10:50 ` Rafael J. Wysocki
2021-03-18 15:22 ` Rafael J. Wysocki
2021-03-20 8:25 ` Mike Rapoport
2021-03-22 16:57 ` Rafael J. Wysocki
2021-03-23 19:26 ` [PATCH] ACPI: tables: x86: Reserve memory occupied by ACPI tables Rafael J. Wysocki
2021-03-24 8:24 ` Mike Rapoport
2021-03-24 13:27 ` Rafael J. Wysocki
2021-03-24 13:49 ` George Kennedy
2021-03-24 15:42 ` George Kennedy
2021-03-24 15:44 ` Rafael J. Wysocki
2021-03-07 7:46 ` [PATCH 1/1] ACPI: fix acpi table use after free Mike Rapoport
2021-03-09 17:54 ` Mike Rapoport
2021-03-09 18:29 ` Rafael J. Wysocki
2021-03-09 20:16 ` Mike Rapoport
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