linux-kernel - Re: [PATCH] staging: android: ion: Bail out upon SIGKILL when allocating 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: <37ac2d6d-3fc6-53eb-c2cd-20c0e9ac2054@redhat.com>
Date:   Mon, 1 Jul 2019 17:21:39 -0400
From:   Laura Abbott <labbott@...hat.com>
To:     Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>,
        Sumit Semwal <sumit.semwal@...aro.org>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] staging: android: ion: Bail out upon SIGKILL when
 allocating memory.

On 7/1/19 5:02 PM, Tetsuo Handa wrote:
> On 2019/07/01 23:02, Sumit Semwal wrote:
>>> Acked-by: Laura Abbott <labbott@...hat.com>
>> fwiw, Acked-by: Sumit Semwal <sumit.semwal@...aro.org>
> 
> Thank you for responding. You can carry this patch via whichever tree you like.
> 
> By the way, is "memory allocation from ion_system_heap_allocate() is calling
> ion_system_heap_shrink()"
> ( https://lkml.kernel.org/r/03763360-a7de-de87-eb90-ba7838143930@I-love.SAKURA.ne.jp )
> what we want? Such memory allocations might not want to call shrinkers...
> 

For what Ion gets typically used for we do want to be calling shrinkers.
I've had discussions with people in the past about the risk of Ion as
DoS vector due to its ability to allocate large amounts of memory.
At the very least, we probably shouldn't be trying to call the Ion shrinker
when we're in the middle of an ion allocation since shrinking won't do us
any good. We're in the process of re-working Ion at the moment so this
might be a good topic to bring up again.

Thanks,
Laura