CVE request: kernel: perf_counter: Fix buffer overflow in perf_copy_attr()

[Eugene Teo <eugeneteo () kernel sg>]

kernel/perf_counter.c was introduced in commit 0793a61d (v2.6.31-rc1).

"If we pass a big size data over perf_counter_open() syscall, the kernel 
will copy this data to a small buffer, it will cause kernel crash."

Upstream commit: b3e62e35058fc744ac794611f4e79bcd1c5a4b83

Thanks, Eugene