CVE-2012-0879: Medium severity linux kernel vulnerability
The I/O implementation for block devices in the Linux kernel before 2.6.33 does not properly handle the CLONEIO feature, which allows local users to cause a denial of service (I/O instability) by starting multiple processes that share an I/O context.
Other sources
With CLONEIO, copyio() increments both ioc->refcount and ioc->nrtasks. However exitiocontext() only decrements ioc->refcount if ioc->nrtasks reaches 0.
With CLONEIO, parent's iocontext->nrtasks is incremented, but never decremented whenever copyprocess() fails afterwards, which prevents xitiocontext() from calling IO schedulers exit functions.
An unprivileged local user could use these flaws cause denial of service.
Upstream fixes: http://git.kernel.org/linus/61cc74fbb87af6aa551a06a370590c9bc07e29d9 http://git.kernel.org/linus/b69f2292063d2caf37ca9aec7d63ded203701bf3
References: http://comments.gmane.org/gmane.linux.kernel/922519
— Red Hat
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2012-0879?
CVE-2012-0879 has a moderate severity rating as it can lead to denial of service and I/O instability.
What systems are affected by CVE-2012-0879?
CVE-2012-0879 affects various versions of the Linux kernel prior to 2.6.33, as well as some specific Linux distributions like Ubuntu 10.04 and Debian 6.0.
How do I fix CVE-2012-0879?
To fix CVE-2012-0879, users should upgrade to a Linux kernel version that is 2.6.33 or later.
What exploit is associated with CVE-2012-0879?
CVE-2012-0879 is exploited through the improper handling of the CLONE_IO feature which allows local users to create I/O instability.
What is the impact of CVE-2012-0879?
The impact of CVE-2012-0879 is primarily the potential for denial of service attacks that disrupt I/O operations on affected systems.