CVE-2020-7453

In FreeBSD 12.1-STABLE before r359021, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r359020, and 11.3-RELEASE before 11.3-RELEASE-p7, a missing null termination check in the jail_set configuration option "osrelease" may return more bytes with a subsequent jail_get system call allowing a malicious jail superuser with permission to create nested jails to read kernel memory.