An updated mingetty package that fixes three bugs is now available for Red Hat Enterprise Linux 6.
The mingetty program is a lightweight, minimalist getty program for use only on virtual consoles. The mingetty program is not suitable for serial lines (the mgetty program should be used in that case).
- Prior to this update, when mingetty was invoked with the "--chroot" option, mingetty did not change the working directory to the new root. Furthermore, mingetty continued even if setting constraints specified by the "--chroot", "--chdir", and "--nice" options failed. As a result, a user was able to escape from the changed root by using relative paths. Also, it was possible for a user to obtain a process with a different process priority. These problems have been resolved in this update so that the working directory is now changed to the new root directory, all failures are now recognized, and mingetty terminates with an error reported to the system log.
- Prior to this update, when invoking mingetty with a TTY name (a non-option position argument) that was longer than 39 ASCII characters, a buffer overflow occurred and the mingetty stack content could have become corrupted. This bug has been fixed in this update so that only the first 39 bytes (34 bytes in case of a relative path) from the TTY name are now copied.
- Prior to this update, when using a login name longer than 39 characters, such login name was silently refused and mingetty terminated. With this update, login names with the length up to the current runtime limit are now accepted; login names that are above the limit are refused, an error is reported to the system log, and mingetty terminates.
All users of mingetty should upgrade to this updated package, which fixes these bugs.