oss-security - CVE request: kernel: mm: avoid wrapping vm_pgoff in mremap() and stack expansions

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

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

Message-ID: <20110624201950.GA8319@dhcp-25-225.brq.redhat.com>
Date: Fri, 24 Jun 2011 22:19:50 +0200
From: Petr Matousek <pmatouse@...hat.com>
To: oss-security@...ts.openwall.com
Cc: "Steven M. Christey" <coley@...us.mitre.org>,
        Joshua Bressers <bressers@...hat.com>, Eugene Teo <eteo@...hat.com>
Subject: CVE request: kernel: mm: avoid wrapping vm_pgoff in mremap() and
 stack expansions

Description of the problem:
The normal mmap paths all avoid creating a mapping where the pgoff
inside the mapping could wrap around due to overflow.  However, an
expanding mremap() can take such a non-wrapping mapping and make it
bigger and cause a wrapping condition. There is also another case
where we expand mappings hiding in plain sight: the automatic stack
expansion.

The wrapping condition can cause a BUG_ON() due to terminally
confusing the vma_prio_tree code.

Upstream patches:
982134ba62618c2d69fbbbd166d0a11ee3b7e3d8 mremap
a626ca6a656450e9f4df91d0dda238fff23285f4 stack expansion downwards
42c36f63ac1366ab0ecc2d5717821362c259f517 stack expansion upwards

References:
https://bugzilla.redhat.com/show_bug.cgi?id=716538
http://www.spinics.net/lists/stable-commits/msg11385.html
http://www.spinics.net/lists/linux-mm/msg17093.html
http://groups.google.com/group/fa.linux.kernel/msg/9e43ab898c5e6d16

Thanks,
-- 
Petr Matousek / Red Hat Security Response Team

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.