A vulnerability was discovered and corrected in the Linux 2.6 kernel:

A vulnerability in Linux kernel caused by insecure allocation of user
space memory when translating system call inputs to 64-bit. A stack
pointer underflow can occur when using the compat_alloc_user_space
method with an arbitrary length input. (CVE-2010-3081)

To update your kernel, please follow the directions located at:

http://www.mandriva.com/en/security/kernelupdate