Null pointer dereference

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 jailset configuration option "osrelease" may return more bytes with a subsequent jailget system call allowing a...