Bug 2181545

Description of problem:
I reproduced [0] in Fedora Rawhide. I file it for documentation purpose and to track it for Fedora, too.

[0] https://bugzilla.redhat.com/show_bug.cgi?id=2181478

Running the command `systemctl reload autofs.service` returns to the prompt without any output (no news are good news, right?). But checking the service status by running `systemctl status autofs.service` shows that the main process exited.

Instead of reloading the config the status changed from active to failed. To recover from this issue run `systemctl start autofs.service`.

Version-Release number of selected component (if applicable):
libsss_autofs-2.8.2-4.fc38.x86_64
autofs-5.1.8-9.fc39.x86_64
kernel 6.3.0-0.rc3.20230322gita1effab7a3a3.31.fc39.x86_64

How reproducible:


Steps to Reproduce:
1. dnf in autofs
2. systemctl enable --now autofs
3. systemctl reload autofs.service

Actual results:

---
# systemctl --no-pager status autofs.service
× autofs.service - Automounts filesystems on demand
     Loaded: loaded (/usr/lib/systemd/system/autofs.service; enabled; preset: disabled)
    Drop-In: /usr/lib/systemd/system/service.d
             └─10-timeout-abort.conf
     Active: failed (Result: core-dump) since Fri 2023-03-24 13:36:04 CET; 51min ago
   Duration: 15.555s
    Process: 985 ExecStart=/usr/sbin/automount $OPTIONS --systemd-service --dont-check-daemon (code=dumped, signal=SEGV)
    Process: 999 ExecReload=/usr/bin/kill -HUP $MAINPID (code=exited, status=0/SUCCESS)
   Main PID: 985 (code=dumped, signal=SEGV)
        CPU: 24ms

Mar 24 13:35:48 fedora-rawhide-2023-03-24 systemd[1]: Starting autofs.service - Automounts f…d...
Mar 24 13:35:48 fedora-rawhide-2023-03-24 systemd[1]: Started autofs.service - Automounts fi…and.
Mar 24 13:36:03 fedora-rawhide-2023-03-24 systemd[1]: Reloading autofs.service - Automounts …d...
Mar 24 13:36:03 fedora-rawhide-2023-03-24 systemd[1]: Reloaded autofs.service - Automounts f…and.
Mar 24 13:36:04 fedora-rawhide-2023-03-24 systemd[1]: autofs.service: Main process exited, c…SEGV
Mar 24 13:36:04 fedora-rawhide-2023-03-24 systemd[1]: autofs.service: Failed with result 'co…mp'.
Hint: Some lines were ellipsized, use -l to show in full.
---

Expected results:
Reload should work without taking the service down.

Additional info:
GDB back trace:

---
[root@fedora-rawhide-2023-03-24 coredump]# coredumpctl list /usr/sbin/automount 
TIME                        PID UID GID SIG     COREFILE EXE                   SIZE
Fri 2023-03-24 13:36:03 CET 985   0   0 SIGSEGV present  /usr/sbin/automount 217.0K
[root@fedora-rawhide-2023-03-24 coredump]# coredumpctl debug
           PID: 985 (automount)
           UID: 0 (root)
           GID: 0 (root)
        Signal: 11 (SEGV)
     Timestamp: Fri 2023-03-24 13:36:03 CET (55min ago)
  Command Line: /usr/sbin/automount --systemd-service --dont-check-daemon
    Executable: /usr/sbin/automount
 Control Group: /system.slice/autofs.service
          Unit: autofs.service
         Slice: system.slice
       Boot ID: c1f22570133f4c7f9a150526bfc81332
    Machine ID: cb980186c0a447eeb3df7516ce01bb15
      Hostname: fedora-rawhide-2023-03-24
       Storage: /var/lib/systemd/coredump/core.automount.0.c1f22570133f4c7f9a150526bfc81332.985.1679661363000000.zst (present)
  Size on Disk: 217.0K
       Message: Process 985 (automount) of user 0 dumped core.
                
                Module libpcre2-8.so.0 from rpm pcre2-10.42-1.fc38.1.x86_64
                Module libselinux.so.1 from rpm libselinux-3.5-1.fc39.x86_64
                Module libcrypto.so.3 from rpm openssl-3.0.8-2.fc39.x86_64
                Module libkeyutils.so.1 from rpm keyutils-1.6.1-6.fc38.x86_64
                Module libkrb5support.so.0 from rpm krb5-1.20.1-9.fc39.x86_64
                Module libz.so.1 from rpm zlib-1.2.13-3.fc38.x86_64
                Module liblz4.so.1 from rpm lz4-1.9.4-2.fc38.x86_64
                Module libzstd.so.1 from rpm zstd-1.5.4-1.fc39.x86_64
                Module liblzma.so.5 from rpm xz-5.4.1-1.fc38.x86_64
                Module libcap.so.2 from rpm libcap-2.48-6.fc38.x86_64
                Module libcom_err.so.2 from rpm e2fsprogs-1.46.5-4.fc38.x86_64
                Module libk5crypto.so.3 from rpm krb5-1.20.1-9.fc39.x86_64
                Module libkrb5.so.3 from rpm krb5-1.20.1-9.fc39.x86_64
                Module libgssapi_krb5.so.2 from rpm krb5-1.20.1-9.fc39.x86_64
                Module libxml2.so.2 from rpm libxml2-2.10.3-3.fc38.x86_64
                Module libsystemd.so.0 from rpm systemd-253.1-4.fc39.x86_64
                Module libtirpc.so.3 from rpm libtirpc-1.3.3-1.fc38.x86_64
                Stack trace of thread 1001:
                #0  0x00007f1dd305a530 n/a (n/a + 0x0)
                #1  0x00007f1dd357807a start_thread (libc.so.6 + 0x8d07a)
                #2  0x00007f1dd35fe78c __clone3 (libc.so.6 + 0x11378c)
                
                Stack trace of thread 985:
                #0  0x00007f1dd35298a8 __sigtimedwait (libc.so.6 + 0x3e8a8)
                #1  0x00007f1dd3528f74 sigwait (libc.so.6 + 0x3df74)
                #2  0x00005614c13b7a83 main (automount + 0xba83)
                #3  0x00007f1dd3512b4a __libc_start_call_main (libc.so.6 + 0x27b4a)
                #4  0x00007f1dd3512c0b __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x27c0b)
                #5  0x00005614c13b82b5 _start (automount + 0xc2b5)
                
                Stack trace of thread 988:
                #0  0x00007f1dd3574ad9 __futex_abstimed_wait_common (libc.so.6 + 0x89ad9)
                #1  0x00007f1dd3577479 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x8c479)
                #2  0x00005614c13ca643 st_queue_handler (automount + 0x1e643)
                #3  0x00007f1dd3578207 start_thread (libc.so.6 + 0x8d207)
                #4  0x00007f1dd35fe78c __clone3 (libc.so.6 + 0x11378c)
                
                Stack trace of thread 987:
                #0  0x00007f1dd3574ad9 __futex_abstimed_wait_common (libc.so.6 + 0x89ad9)
                #1  0x00007f1dd3577479 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x8c479)
                #2  0x00007f1dd3702114 alarm_handler (libautofs.so + 0x13114)
                #3  0x00007f1dd3578207 start_thread (libc.so.6 + 0x8d207)
                #4  0x00007f1dd35fe78c __clone3 (libc.so.6 + 0x11378c)
                
                Stack trace of thread 991:
                #0  0x00007f1dd35f113d __poll (libc.so.6 + 0x10613d)
                #1  0x00005614c13c0950 handle_packet (automount + 0x14950)
                #2  0x00005614c13c1b35 handle_mounts (automount + 0x15b35)
                #3  0x00007f1dd3578207 start_thread (libc.so.6 + 0x8d207)
                #4  0x00007f1dd35fe78c __clone3 (libc.so.6 + 0x11378c)
                
                Stack trace of thread 1003:
                #0  0x00007f1dd356bac6 _IO_getc (libc.so.6 + 0x80ac6)
                #1  0x00007f1dd3088b48 read_one (lookup_file.so + 0x2b48)
                #2  0x00007f1dd3089d4e lookup_read_map (lookup_file.so + 0x3d4e)
                #3  0x00005614c13ccf97 do_read_map (automount + 0x20f97)
                #4  0x00005614c13cd153 read_file_source_instance (automount + 0x21153)
                #5  0x00005614c13cd738 lookup_nss_read_map (automount + 0x21738)
                #6  0x00005614c13cf5c9 do_readmap (automount + 0x235c9)
                #7  0x00007f1dd3578207 start_thread (libc.so.6 + 0x8d207)
                #8  0x00007f1dd35fe78c __clone3 (libc.so.6 + 0x11378c)
                
                Stack trace of thread 994:
                #0  0x00007f1dd35f113d __poll (libc.so.6 + 0x10613d)
                #1  0x00005614c13c0950 handle_packet (automount + 0x14950)
                #2  0x00005614c13c1b35 handle_mounts (automount + 0x15b35)
                #3  0x00007f1dd3578207 start_thread (libc.so.6 + 0x8d207)
                #4  0x00007f1dd35fe78c __clone3 (libc.so.6 + 0x11378c)
                ELF object binary architecture: AMD x86-64

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Reading symbols from /usr/sbin/automount...

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Reading symbols from /root/.cache/debuginfod_client/2c6e4764416e6d039de28a5b2f73b5471a59285e/debuginfo...
[New LWP 1001]                                                                                   
[New LWP 985]
[New LWP 988]
[New LWP 987]
[New LWP 991]
[New LWP 1003]
[New LWP 994]
                                                                                                 --Type <RET> for more, q to quit, c to continue without paging--c
[Thread debugging using libthread_db enabled]                                                    
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `/usr/sbin/automount --systemd-service --dont-check-daemon'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007f1dd305a530 in ?? ()
[Current thread is 1 (Thread 0x7f1dd0bfb6c0 (LWP 1001))]
(gdb) bt
#0  0x00007f1dd305a530 in ?? ()
#1  0x00007f1dd3575100 in __GI___nptl_deallocate_tsd () at nptl_deallocate_tsd.c:73
#2  __GI___nptl_deallocate_tsd () at nptl_deallocate_tsd.c:22
#3  0x00007f1dd357807a in start_thread (arg=<optimized out>) at pthread_create.c:455
#4  0x00007f1dd35fe78c in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
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