A security issue has been reported in the Linux Kernel, which can be exploited by malicious, local users to potentially cause a DoS (Denial of Service) or gain escalated privileges.

The security issue is caused due to the kernel accepting certain 32bit parameters passed in a 64bit register from userspace without ensuring that the value is correctly sign extended. This may be exploited to crash a system or potentially gain escalated privileges by passing specially crafted parameters to affected system calls.

Reportedly, the following architectures use a vulnerable ABI system when running a 64bit kernel and a 64bit userspace:
* S390
* PowerPC
* SPARC64
* MIPS

Solution
Fixed in version 2.6.27.12 and 2.6.28.1 for the s390 and PowerPC (64bit) architectures.
Further details available in Customer Area

Provided and/or discovered by
Red Hat credits Christian Borntraeger.

Changelog
Further details available in Customer Area

Original Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=479969

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area