Bug 245773 (CVE-2007-2875) - CVE-2007-2875 cpuset information leak
Summary: CVE-2007-2875 cpuset information leak
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2007-2875
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
medium
Target Milestone: ---
Assignee: Don Howard
QA Contact: Martin Jenner
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2007-06-26 17:16 UTC by Marcel Holtmann
Modified: 2019-09-29 12:20 UTC (History)
3 users (show)

Fixed In Version: RHSA-2007-0705
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2007-09-13 09:13:17 UTC


Attachments (Terms of Use)


Links
System ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2007:0705 normal SHIPPED_LIVE Important: kernel security update 2007-09-13 09:21:22 UTC

Description Marcel Holtmann 2007-06-26 17:16:40 UTC
From iDefense:

Local exploitation of an information disclosure vulnerability within the
Linux Kernel allows attackers to obtain sensitive information from
kernel memory.

This vulnerability specifically exists in the "cpuset_tasks_read"
function. This function is responsible for supplying user-land
processes with data when they read from the /dev/cpuset/tasks file. The
code excerpt below shows the problem area.

  1754          if (*ppos + nbytes > ctr->bufsz)
  1755                  nbytes = ctr->bufsz - *ppos;
  1756          if (copy_to_user(buf, ctr->buf + *ppos, nbytes))

By reading from an offset (*ppos) larger than the contents of the file,
an attacker can cause an integer underflow to occur in the subtraction
on line 1755. This will result in the "copy_to_user" function on line
1756 to be called with a memory address located at a lower address than
the start of the intended buffer. This memory could potentially contain
sensitive information such as security tokens or passwords.

Exploitation of this vulnerability allows attackers to obtain sensitive
information from kernel memory.

In order to exploit this vulnerability, an attacker would need access to
open the /dev/cpuset/tasks file. It is important to note that this file
does not exist unless the cpuset file system has been mounted.
Additionally, this functionality is not included by default in a
vanilla kernel build.

Furthermore, because of checks at the VFS layer and in the
'copy_to_user()' function, an attacker cannot use arbitrary values.
However, on 32-bit systems it is easily exploitable.

Comment 1 Don Howard 2007-08-29 19:29:54 UTC
A patch for this issue has been included in build 2.6.18-8.1.9.

Comment 4 Red Hat Bugzilla 2007-09-13 09:13:17 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2007-0705.html



Note You need to log in before you can comment on or make changes to this bug.