[alsa-devel] [PATCH 0/2] ALSA: pcm: implement the anonymous dup v3

[Jaroslav Kysela]

Dne 31.1.2019 v 13:26 Mark Brown napsal(a):
> On Thu, Jan 31, 2019 at 09:08:04AM +0100, Takashi Iwai wrote:
>> Mark Brown wrote:
> 
>>> anything O_APPEND based.  My understanding is that this is fundamentally
>>> a risk mitigation thing - by not having any of the sound kernel
>>> interfaces available to the applications affected there's no possibility
>>> that any problems in the sound code can cause security issues.
> 
>> The patch 2 implements exactly that kind of access restriction, so
>> that the passed fd won't do anything else than wished.
> 
> Yeah.
> 
>> If we want to be super-conservative, the implementation could be even
>> simpler -- instead of filtering, we may pass a minimum fd ops that
>> contains only mmap and release for the anon-dup fd...
> 
> I think that'd definitely help address the concerns.

A possible implementation:

http://git.alsa-project.org/?p=alsa-kernel.git;a=commitdiff;h=ca15bc69a984cc0eae2c43d0a49c66a20c937f39

				Jaroslav

-- 
Jaroslav Kysela <perex at perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.