/etc/sysctl.d/ Current File: //etc/sysctl.d/10-zeropage.conf

# Protect the zero page of memory from userspace mmap to prevent kernel
# NULL-dereference attacks against potential future kernel security
# vulnerabilities.  (Added in kernel 2.6.23.)
#
# While this default is built into the Ubuntu kernel, there is no way to
# restore the kernel default if the value is changed during runtime; for
# example via package removal (e.g. wine, dosemu).  Therefore, this value
# is reset to the secure default each time the sysctl values are loaded.
vm.mmap_min_addr = 65536