oss-security - Re: CVE request - kernel: find_keyring_by

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date: Tue, 27 Apr 2010 20:11:10 -0400 (EDT)
From: Josh Bressers <bressers@...hat.com>
To: oss-security@...ts.openwall.com
Cc: coley@...us.mitre.org
Subject: Re: CVE request - kernel: find_keyring_by_name() can
 gain the freed keyring

Please use CVE-2010-1437

Thanks.

-- 
    JB


----- "Eugene Teo" <eugene@...hat.com> wrote:

> Reported by Toshiyuki Okajima. find_keyring_by_name() can gain the 
> keyring which has been already freed. And then, its space (which is 
> gained by find_keyring_by_name()) is broken by accessing the freed 
> keyring as the available keyring:
> 
> 1) If the space of the freed keyring is reallocated for other purpose
> 
> (ie. filp SLUB), the data of the filp object may be destroyed by the 
> user of the freed keyring. (SLUB configuration can share the freed
> space 
> with other same-size slabs.)
> 
> 2) If the slab space of the freed keyring is released into the system,
> 
> the system panic may happen because accessing the space of the freed 
> keyring causes the page-fault.
> 
> Example: (we can easily confirm this problem if CONFIG_SLUB is "y".)
> [1] with CONFIG_SLUB_DEBUG_ON
> While we are executing my reproducer (which is attached), we can
> notice 
> that the user of the freed keyring breaks its space:
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> # ./reproducer &
> ...
> # dmesg
> ...
> =============================================================================
> BUG key_jar: Poison overwritten
> [...]
> 
> More info:
> http://www.gossamer-threads.com/lists/linux/kernel/1216391
> https://patchwork.kernel.org/patch/94038/
> https://bugzilla.redhat.com/show_bug.cgi?id=585094
> 
> Thanks, Eugene

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.