Description of problem:

autofs is configured with the combination of +auto.master and the local direct map lookups.
It works well at autofs-5.1.4-83.el8.x86_64. 
After upgrading to autofs-5.1.4-93.el8.x86_64, autofs fails to start.


Version-Release number of selected component (if applicable):

RHEL 8.8
kernel-4.18.0-477.10.1.el8_8.x86_64
autofs-5.1.4-93.el8.x86_64

How reproducible:


Steps to Reproduce:

There are 3 scenarios:

(1) scenario-1

#### Configuration 1: Direct maps in network +auto.master map plus direct map specified in /etc/auto.master
“+auto.master maps contain a /- direct map” and “/etc/auto.master also has a /- direct map from a local file”
No clashing paths in the direct maps.

/etc/auto.master contains:
/homes  /etc/auto.lhome   # Script that provides mount path
+auto.master
/- /etc/auto.direct

/etc/auto.scis-utils contains:
/usr/scis-utils     -vers=3,ro      scis-nfs:/export/scis/readonly/scis-utils

(2) scenario-2
#### Configuration 2: Direct and Indirect maps with duplicate root paths in +auto.master and /etc/auto.master
+auto.master maps have entries where direct and indirect map paths clash with other direct and indirect maps specified in local maps.
EG:
+auto.master map contain:
/-    with list of many direct map NFS mount paths, including “/usr/scis-utils     -vers=3,ro      scis-nfs:/export/scis/readonly/scis-utils”
/home    with list of many NFS mount paths

/etc/auto.master contains:
/home   /etc/auto.lhome   # Script that provides mount path
+auto.master
/- /etc/auto.scis-utils

/etc/auto.scis-utils contains:
/usr/scis-utils     -vers=3,ro      scis-nfs:/export/scis/readonly/scis-utils

Clashes:
/home root of an indirect map is in both the +auto.master map and listed in /etc/auto.master
/usr/scis-utils path of a direct map is in both the +auto.master /- direct map, and the /etc/auto.scis-utils direct map.

(3)scenario-3

#### Configuration 3: Two sources for the /home indirect map. First entry in /etc/auto.master should apply.
+auto.master maps have entries where indirect map paths clash with other indirect maps specified in local maps.
+auto.master map contain:
/-    with list of many direct map NFS mount paths, including “/usr/scis-utils     -vers=3,ro      scis-nfs:/export/scis/readonly/scis-utils”
/home    with list of many NFS mount paths

/etc/auto.master contains:
/home   /etc/auto.lhome   # Script that provides mount path
+auto.master

(4) Analysis:
The first two scenarios (combinations of multiple direct maps) are triggering an automount seg fault on boot, or when doing a “systemctl reload autofs” or “systemctl restart autofs”.

The third scenario (configuration of overlaid/duplicate indirect maps for /home) works on boot, but fails if a reload or restart is performed after initial boot.

Correct operation should allow multiple sources for direct maps. 
Correct operation should allow multiple sources for indirect maps, with a ‘first specified’ hierarchy defining the map source in use.
Customer have been operating in this mode for many years. Previous automount versions supported this happily on RHEL, CentOS and Ubuntu systems.

Actual results:
autofs fails to start by causing core dump.

Expected results:
autofs should start as expected.

Additional info:

Impact: Enterprise wide outage effecting all RHEL 8 users (800 systems)
Classified systems so no sosreport or remote access available.
Customer is unable to provide a core dump due to the classified nature of these systems.