CVE-2011-2495
fs/proc/base.c in the Linux kernel before 2.6.39.4 does not properly restrict access to /proc/#####/io files, which allows local users to obtain sensitive I/O statistics by polling a file, as demonstrated by discovering the length of another user’s password.
Date published : 2012-06-13
http://ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39.4