|Summary:||CVE-2007-2875 cpuset information leak|
|Product:||[Other] Security Response||Reporter:||Marcel Holtmann <holtmann>|
|Component:||vulnerability||Assignee:||Don Howard <dhoward>|
|Status:||CLOSED ERRATA||QA Contact:||Martin Jenner <mjenner>|
|Version:||unspecified||CC:||eteo, qcai, security-response-team|
|Fixed In Version:||RHSA-2007-0705||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2007-09-13 09:13:17 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
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