Bug 87913 - Kernel: "is_hugepage_only_range()" Denial of Service (CAN-2005-0916)
Bug#: 87913 Product:  Gentoo Security Version: unspecified Platform: All
OS/Version: All Status: RESOLVED Severity: normal Priority: P2
Resolution: FIXED Assigned To: security@gentoo.org Reported By: formula7@gentoo.org
Component: Kernel
URL:  http://secunia.com/advisories/14718/
Summary: Kernel: "is_hugepage_only_range()" Denial of Service (CAN-2005-0916)
Keywords:  
Status Whiteboard: [linux < 2.6.12]
Opened: 2005-04-04 07:44 0000
Description:   Opened: 2005-04-04 07:44 0000 
Description:
Daniel McNeil has reported a vulnerability in the Linux Kernel, which can be exploited by malicious, local users to cause a DoS (Denial of Service).

The vulnerability is caused due to an error in the AIO (Asynchronous I/O) support within the "is_hugepage_only_range()" function. This can be exploited via a specially crafted program calling the "io_queue_init()" function and then exiting without calling the "io_queue_release()" function.

Successful exploitation crashes the system on PPC64 and IA64 architectures, but requires that CONFIG_HUGETLB_PAGE is enabled.

The vulnerability has been reported in versions 2.6.8 and 2.6.11. Other versions may also be affected.

Solution:
Grant only trusted users access to affected systems.

------- Comment #1 From Kerin Millar 2005-04-11 12:10:40 0000 ------- 
Daniel McNiel also came up with a patch which I shall attach here (lifted
verbatim from Debian's patchset). Reference:

http://linux.bkbits.net:8080/linux-2.6/cset@4248c8c0es30_4YVdwa6vteKi7h_nw

------- Comment #2 From Kerin Millar 2005-04-11 12:12:06 0000 ------- 
Created an attachment (id=56012) [details]
patch to rectify CAN-2005-0916

This instance was taken from debian-2.6.11-2. Also available from:
http://linux.bkbits.net:8080/linux-2.6/cset@4248c8c0es30_4YVdwa6vteKi7h_nw

------- Comment #3 From Joshua Kinard 2005-04-23 22:29:43 0000 ------- 
mips-sources fixed.

------- Comment #4 From solar 2005-05-02 07:47:02 0000 ------- 
Kumba does this effect the mips arch? 
The advisory only mentions ia64 and ppc64

------- Comment #5 From Tim Yamin (RETIRED) 2005-05-05 13:36:16 0000 ------- 
Kernel maintainers: This affects 2.6.11 so gentoo-sources et al. still need
patching.

------- Comment #6 From Daniel Drake 2005-05-10 15:51:04 0000 ------- 
Fixed in gentoo-sources-2.6.11-r8

------- Comment #7 From Markus Rothe 2005-05-11 09:35:46 0000 ------- 
stable on ppc64

------- Comment #8 From Aron Griffis (RETIRED) 2005-05-11 19:36:26 0000 ------- 
stable on ia64

------- Comment #9 From Joshua Kinard 2005-05-17 21:06:54 0000 ------- 
solar: Because the patch touches files in mm/ and include/linux/, I felt it
prudent to add it into our patchset anyways.  While the chances of it affecting
us are incredibly slim, if none at all, it shouldn't hurt things to include it
on the offchance.

------- Comment #10 From Tim Yamin (RETIRED) 2005-11-26 03:06:53 0000 ------- 
All fixed, closing bug.