kernel: md: NULL pointer deref when accessing suspend_* sysfs attributes

The md driver drivers/md/md.c in the Linux kernel before 2.6.30.2 might allow local users to cause a denial of service NULL pointer dereference via vectors related to "suspend sysfs attributes" and the 1 suspendlostore or 2 suspendhistore functions. NOTE: this is only a vulnerability when sysfs i...