v6.5: Crash due to segmentation fault

[IsHacker003]

Versions

• Pi-hole: v6.4
• Web: v6.4.1
• FTL: v6.5

Platform

• OS and version: Debian 13 Trixie

• Platform: Android (via Trixie app)

Expected behavior

FTL should not crash.

Actual behavior / bug

FTL kills itself automatically when there are more than ~2 queries/second at random times. Log:

2026-02-22 15:39:32.469 UTC [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: ---------------------------->  FTL crashed!  <----------------------------
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: Please report a bug at https://github.com/pi-hole/FTL/issues
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: and include in your report already the following details:
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: FTL has been running for 272 seconds
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: FTL branch: master
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: FTL version: v6.5
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: FTL commit: f8883098
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: FTL date: 2026-02-17 20:20:12 +0000
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: FTL user: started as pihole, ended as pihole
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: Compiled for linux/arm64/v8 (compiled on CI) using cc (Alpine 15.2.0) 15.2.0
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: Process details: MID: 17009
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO:                  PID: 17009
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO:                  TID: 21089
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO:                  Name: civetweb-worker
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO: Received signal: Segmentation fault
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO:      at address: 0x74656e2e5c7479
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO:      with code:  SEGV_MAPERR (Address not mapped to object)
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO: !!! INFO: pihole-FTL has not been compiled with glibc/backtrace support, not generating one !!!
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO: ------ Listing content of directory /dev/shm ------
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO: File Mode User:Group      Size  Filename
2026-02-22 15:39:32.471 UTC [17009/T21089] INFO: rwxrwxrwx root:root       380   .
2026-02-22 15:39:32.472 UTC [17009/T21089] INFO: rwxr-xr-x root:root         4k  ..
2026-02-22 15:39:32.472 UTC [17009/T21089] INFO: rw-r--r-- nqptp:nqptp      72   nqptp
2026-02-22 15:39:32.473 UTC [17009/T21089] INFO: rw------- pihole:pihole   768k  FTL-17006-recycler
2026-02-22 15:39:32.474 UTC [17009/T21089] INFO: rw------- pihole:pihole    12k  FTL-17006-dns-cache-lookup
2026-02-22 15:39:32.478 UTC [17009/T21089] INFO: rw------- pihole:pihole     8k  FTL-17006-domains-lookup
2026-02-22 15:39:32.478 UTC [17009/T21089] INFO: rw------- pihole:pihole     4k  FTL-17006-clients-lookup
2026-02-22 15:39:32.479 UTC [17009/T21089] INFO: rw------- pihole:pihole   555k  FTL-17006-fifo-log
2026-02-22 15:39:32.479 UTC [17009/T21089] INFO: rw------- pihole:pihole    32k  FTL-17006-per-client-regex
2026-02-22 15:39:32.479 UTC [17009/T21089] INFO: rw------- pihole:pihole    60k  FTL-17006-dns-cache
2026-02-22 15:39:32.479 UTC [17009/T21089] INFO: rw------- pihole:pihole     8k  FTL-17006-overTime
2026-02-22 15:39:32.480 UTC [17009/T21089] INFO: rw------- pihole:pihole     4M  FTL-17006-queries
2026-02-22 15:39:32.480 UTC [17009/T21089] INFO: rw------- pihole:pihole    28k  FTL-17006-upstreams
2026-02-22 15:39:32.480 UTC [17009/T21089] INFO: rw------- pihole:pihole   340k  FTL-17006-clients
2026-02-22 15:39:32.480 UTC [17009/T21089] INFO: rw------- pihole:pihole    24k  FTL-17006-domains
2026-02-22 15:39:32.481 UTC [17009/T21089] INFO: rw------- pihole:pihole    80k  FTL-17006-strings
2026-02-22 15:39:32.481 UTC [17009/T21089] INFO: rw------- pihole:pihole   144   FTL-17006-settings
2026-02-22 15:39:32.481 UTC [17009/T21089] INFO: rw------- pihole:pihole   344   FTL-17006-counters
2026-02-22 15:39:32.482 UTC [17009/T21089] INFO: rw------- pihole:pihole   120   FTL-17006-lock
2026-02-22 15:39:32.482 UTC [17009/T21089] INFO: ---------------------------------------------------
2026-02-22 15:39:32.482 UTC [17009/T21089] INFO: Please also include some lines from above the !!!!!!!!! header.
2026-02-22 15:39:32.482 UTC [17009/T21089] INFO: Thank you for helping us to improve our FTL engine!
2026-02-22 15:39:32.482 UTC [17009/T21089] INFO: Shutting down thread...
2026-02-22 15:39:32.482 UTC [17009/T21089] INFO: Asked to terminate by "/usr/bin/pihole-FTL" (PID 17009, user pihole UID 115)
2026-02-22 15:39:32.612 UTC [17009/T17043] INFO: Compiled 4 allow and 168 deny regex for 183 clients in 1542.7 msec
2026-02-22 15:39:32.712 UTC [17009/T17043] INFO: Terminating database thread
2026-02-22 15:39:32.726 UTC [17009/T17044] INFO: Terminating GC thread
2026-02-22 15:39:32.751 UTC [17009/T17046] INFO: Terminating timer thread
2026-02-22 15:39:32.927 UTC [17009M] INFO: Finished final database update
2026-02-22 15:39:32.927 UTC [17009M] INFO: Waiting for threads to join
2026-02-22 15:39:32.927 UTC [17009M] INFO: Thread dns-client (2) is idle, terminating it.
2026-02-22 15:39:32.927 UTC [17009M] INFO: Thread webserver (7) is idle, terminating it.
2026-02-22 15:39:32.927 UTC [17009M] INFO: All threads joined
2026-02-22 15:39:32.929 UTC [17009M] INFO: PID file emptied
2026-02-22 15:39:32.936 UTC [17009M] INFO: Stored 1 API session in the database
2026-02-22 15:39:33.348 UTC [17009M] INFO: ########## FTL terminated after 4m 32s  (code 1)! ##########

Steps to reproduce

Steps to reproduce the behavior:

1. Make lots of DNS requests
2. FTL crashes

Debug Token

• URL: https://tricorder.pi-hole.net/QW6incCf/

Screenshots

If applicable, add screenshots to help explain your problem.

Additional context

Add any other context about the problem here.

[rdwebdesign]

Can you please also include a few log lines that were generated BEFORE this header:

2026-02-22 15:39:32.469 IST [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2026-02-22 15:39:32.470 IST [17009/T21089] INFO: ---------------------------->  FTL crashed!  <----------------------------
2026-02-22 15:39:32.470 IST [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[IsHacker003]

Can you please also include a few log lines that were generated BEFORE this header:

2026-02-22 15:39:32.469 UTC [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: ---------------------------->  FTL crashed!  <----------------------------
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Here it is, this is everything after the log from the previous crash up to the "FTL crashed" header of the most recent crash (the one I posted the log for):

2026-02-22 15:35:00.835 UTC [17006M] INFO: FTL branch: master
2026-02-22 15:35:00.835 UTC [17006M] INFO: FTL version: v6.5
2026-02-22 15:35:00.835 UTC [17006M] INFO: FTL commit: f8883098
2026-02-22 15:35:00.835 UTC [17006M] INFO: FTL date: 2026-02-17 20:20:12 +0000
2026-02-22 15:35:00.835 UTC [17006M] INFO: FTL user: pihole
2026-02-22 15:35:00.835 UTC [17006M] INFO: Compiled for linux/arm64/v8 (compiled on CI) using cc (Alpine 15.2.0) 15.2.0
2026-02-22 15:35:00.842 UTC [17006M] INFO: Wrote config file:
2026-02-22 15:35:00.842 UTC [17006M] INFO:  - 166 total entries
2026-02-22 15:35:00.842 UTC [17006M] INFO:  - 135 entries are default
2026-02-22 15:35:00.842 UTC [17006M] INFO:  - 31 entries are modified
2026-02-22 15:35:00.842 UTC [17006M] INFO:  - 0 entries are forced through environment
2026-02-22 15:35:00.848 UTC [17006M] INFO: Parsed config file /etc/pihole/pihole.toml successfully
2026-02-22 15:35:00.849 UTC [17006M] INFO: PID file does not exist or not readable
2026-02-22 15:35:00.849 UTC [17006M] INFO: No other running FTL process found.
2026-02-22 15:35:00.852 UTC [17006M] INFO: PID of FTL process: 17006
2026-02-22 15:35:00.854 UTC [17006M] INFO: listening on 0.0.0.0 port 53
2026-02-22 15:35:00.855 UTC [17006M] INFO: listening on :: port 53
2026-02-22 15:35:00.860 UTC [17009M] INFO: PID of FTL process: 17009
2026-02-22 15:35:00.864 UTC [17009M] INFO: Database version is 21
2026-02-22 15:35:00.865 UTC [17009M] INFO: Database successfully initialized
2026-02-22 15:35:01.194 UTC [17009M] INFO: NTP sync is disabled
2026-02-22 15:35:01.196 UTC [17009M] INFO: FTL is running as user pihole (UID 115)
2026-02-22 15:35:01.196 UTC [17009/T17047] INFO: Reading certificate from /etc/pihole/tls.pem ...
2026-02-22 15:35:01.198 UTC [17009/T17044] WARNING: Disk shortage ahead: 96% is used (21.9GB used, 22.7GB total) on f2fs filesystem mounted at /
2026-02-22 15:35:01.198 UTC [17009M] INFO: Blocking status is enabled
2026-02-22 15:35:01.199 UTC [17009/T17047] INFO: Using SSL/TLS certificate file /etc/pihole/tls.pem
2026-02-22 15:35:01.203 UTC [17009/T17047] INFO: Web server ports:
2026-02-22 15:35:01.203 UTC [17009/T17047] INFO:   - 0.0.0.0:53080 (HTTP, IPv4, optional, OK)
2026-02-22 15:35:01.203 UTC [17009/T17047] INFO:   - 0.0.0.0:53443 (HTTPS, IPv4, optional, OK)
2026-02-22 15:35:01.203 UTC [17009/T17047] INFO:   - [::]:53080 (HTTP, IPv6, optional, OK)
2026-02-22 15:35:01.203 UTC [17009/T17047] INFO:   - [::]:53443 (HTTPS, IPv6, optional, OK)
2026-02-22 15:35:03.738 UTC [17009/T17043] INFO: Imported 48662 queries from the on-disk database (it has 76077 rows)
2026-02-22 15:35:03.738 UTC [17009/T17047] INFO: Restored 1 API session from the database
2026-02-22 15:35:03.738 UTC [17009/T17043] INFO: Parsing queries in database
2026-02-22 15:35:03.950 UTC [17009/T17043] INFO:   10000 queries parsed...
2026-02-22 15:35:04.193 UTC [17009/T17043] INFO:   20000 queries parsed...
2026-02-22 15:35:04.570 UTC [17009/T17043] INFO:   30000 queries parsed...
2026-02-22 15:35:04.720 UTC [17009/T17043] INFO:   40000 queries parsed...
2026-02-22 15:35:04.824 UTC [17009/T17043] INFO: Imported 48662 queries from the long-term database
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Total DNS queries: 48749
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Cached DNS queries: 12355
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Forwarded DNS queries: 4119
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Blocked DNS queries: 31905
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Unknown DNS queries: 0
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Unique domains: 757
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Unique clients: 182
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> DNS cache records: 1121
2026-02-22 15:35:04.825 UTC [17009/T17043] INFO:  -> Known forward destinations: 1
2026-02-22 15:35:06.708 UTC [17009/T17043] INFO: Compiled 4 allow and 168 deny regex for 182 clients in 1878.9 msec
2026-02-22 15:35:08.722 UTC [17009/T17045] ERROR: Cannot receive UDP DNS reply: Timeout - no response from upstream DNS server
2026-02-22 15:35:08.722 UTC [17009/T17045] INFO: Tried to resolve PTR "e.d.4.2.f.f.a.3.2.8.a.e.0.f.b.6.8.b.5.6.c.a.8.8.0.0.9.4.1.0.4.2.ip6.arpa" on 127.0.0.1#53 (UDP)
2026-02-22 15:35:10.738 UTC [17009/T17045] ERROR: Cannot receive UDP DNS reply: Timeout - no response from upstream DNS server
2026-02-22 15:35:10.738 UTC [17009/T17045] INFO: Tried to resolve PTR "8.3.9.6.d.1.0.d.8.9.6.a.7.c.d.d.8.b.5.6.c.a.8.8.0.0.9.4.1.0.4.2.ip6.arpa" on 127.0.0.1#53 (UDP)
2026-02-22 15:35:12.750 UTC [17009/T17045] ERROR: Cannot receive UDP DNS reply: Timeout - no response from upstream DNS server
2026-02-22 15:35:12.750 UTC [17009/T17045] INFO: Tried to resolve PTR "4.a.2.6.5.9.8.d.5.a.c.6.a.4.1.1.8.b.5.6.c.a.8.8.0.0.9.4.1.0.4.2.ip6.arpa" on 127.0.0.1#53 (UDP)
2026-02-22 15:39:31.046 UTC [17009/T17043] INFO: Gravity database has been updated, reloading now
2026-02-22 15:39:32.469 UTC [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: ---------------------------->  FTL crashed!  <----------------------------
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2026-02-22 15:39:32.470 UTC [17009/T21089] INFO: Please report a bug at https://github.com/pi-hole/FTL/issues

[yubiuser]

The last line before the crash is

Gravity database has been updated, reloading now

Did you update some configuration or client/group management just before the crash?

[IsHacker003]

The last line before the crash is

Gravity database has been updated, reloading now

Did you update some configuration or client/group management just before the crash?

Yes, I was manually updating gravity lists through web interface before it crashed. I reloaded the page after updating and it said connection refused, only for me to find that FTL was dead.

But it probably isn't relevant because this crash still happens when lots of queries are being made, even when gravity is not updating.

[yubiuser]

this crash still happens when lots of queries are being made, even when gravity is not updating.

This is good as it increases the chance that we can catch the bug if it is so easy to reproduce. However, you run it in a very unconventional environment, I don't know if you are able to do the next steps - attach the debugger and capture the logs

https://docs.pi-hole.net/ftldns/gdb/

[natehudson]

I believe I'm experience a very similar issue after upgrading FTL to 6.5 a few days ago on a Raspberry Pi 3 Model B Rev 1.2 running the latest Debian 12 kernel

Linux rputil1 6.12.62+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.62-1+rpt1~bookworm (2026-01-19) aarch64 GNU/Linux

My pihole sees ~2+ queries/second according to the UI and my crash logs seem to have been rotated out, but I will try and grab them next time.

I've tried the development branch overnight last night but it still crashed, don't see a log from this one though.

I've manually installed v6.4.1 from the release binary https://github.com/pi-hole/FTL/releases/tag/v6.4.1 to hopefully get stability back.

Happy to test out any development releases though.

[rdwebdesign]

@natehudson

Next time the crash happens, can you please share the last lines of FTL.log (including a few lines before the "FTL crashed!" line?

[natehudson]

I sure will, yes.

I also wanted to point out that it was strange in that when it crashed, pihole status still showed the green checkmarks, and the main pihole process was still around but the web interface and dns resolution were not working.

[IsHacker003]

I just noticed that it is not reproducible anymore, after I reinstalled Unbound. It still happens but now it is random. I even got to 12 queries/second but nothing happened, but when there were barely any queries it just crashed randomly. The only pattern I noticed is that it happens when I'm actively browsing the web interface.

[IsHacker003]

I sure will, yes.

I also wanted to point out that it was strange in that when it crashed, pihole status still showed the green checkmarks, and the main pihole process was still around but the web interface and dns resolution were not working.

For me everything gets killed, not even the main Pihole process is there.

[ThisCatLikesCrypto]

I get this but it's at seemingly random times:

2026-03-01 09:22:27.152 UTC [1685M] INFO: Asked to terminate by "/sbin/init" (PID 1, user root UID 0)
2026-03-01 09:23:53.632 UTC [1217M] INFO: ########## FTL started on valerie! ##########
2026-03-01 09:23:53.634 UTC [1217M] INFO: FTL branch: master
2026-03-01 09:23:53.634 UTC [1217M] INFO: FTL version: v6.5
2026-03-01 09:23:53.634 UTC [1217M] INFO: FTL commit: f8883098
2026-03-01 09:23:53.634 UTC [1217M] INFO: FTL date: 2026-02-17 20:20:12 +0000
2026-03-01 09:23:53.634 UTC [1217M] INFO: FTL user: pihole
2026-03-01 09:23:53.634 UTC [1217M] INFO: Compiled for linux/amd64 (compiled on CI) using cc (Alpine 15.2.0) 15.2.0
2026-03-01 09:23:53.636 UTC [1217M] INFO: Wrote config file:
2026-03-01 09:23:53.636 UTC [1217M] INFO:  - 166 total entries
2026-03-01 09:23:53.636 UTC [1217M] INFO:  - 163 entries are default
2026-03-01 09:23:53.636 UTC [1217M] INFO:  - 3 entries are modified
2026-03-01 09:23:53.636 UTC [1217M] INFO:  - 0 entries are forced through environment
2026-03-01 09:23:53.640 UTC [1217M] INFO: Parsed config file /etc/pihole/pihole.toml successfully
2026-03-01 09:23:53.640 UTC [1217M] INFO: PID file does not exist or not readable
2026-03-01 09:23:53.640 UTC [1217M] INFO: No other running FTL process found.
2026-03-01 09:23:53.642 UTC [1217M] INFO: PID of FTL process: 1217
2026-03-01 09:23:53.655 UTC [1217M] INFO: listening on 0.0.0.0 port 53
2026-03-01 09:23:53.655 UTC [1217M] INFO: listening on :: port 53
2026-03-01 09:23:53.656 UTC [1217M] INFO: PID of FTL process: 1217
2026-03-01 09:23:53.679 UTC [1217M] ERROR: SQLite3: recovered 13 frames from WAL file /etc/pihole/pihole-FTL.db-wal (283)
2026-03-01 09:23:53.684 UTC [1217M] INFO: Database version is 21
2026-03-01 09:23:53.696 UTC [1217M] INFO: Database successfully initialized
2026-03-01 09:23:54.066 UTC [1217M] INFO: FTL is running as user pihole (UID 996)
2026-03-01 09:23:54.067 UTC [1217/T1300] INFO: Reading certificate from /etc/pihole/tls.pem ...
2026-03-01 09:23:54.067 UTC [1217M] INFO: Blocking status is enabled
2026-03-01 09:23:54.068 UTC [1217/T1300] INFO: Using SSL/TLS certificate file /etc/pihole/tls.pem
2026-03-01 09:23:54.069 UTC [1217/T1300] INFO: Web server ports:
2026-03-01 09:23:54.069 UTC [1217/T1300] INFO:   - 0.0.0.0:80 (HTTP, IPv4, optional, OK)
2026-03-01 09:23:54.069 UTC [1217/T1300] INFO:   - 0.0.0.0:443 (HTTPS, IPv4, optional, OK)
2026-03-01 09:23:54.069 UTC [1217/T1300] INFO:   - [::]:80 (HTTP, IPv6, optional, OK)
2026-03-01 09:23:54.069 UTC [1217/T1300] INFO:   - [::]:443 (HTTPS, IPv6, optional, OK)
2026-03-01 09:23:54.411 UTC [1217/T1296] INFO: Imported 38926 queries from the on-disk database (it has 38926 rows)
2026-03-01 09:23:54.411 UTC [1217/T1296] INFO: Parsing queries in database
2026-03-01 09:23:54.411 UTC [1217/T1300] INFO: Restored 0 API sessions from the database
2026-03-01 09:23:54.453 UTC [1217/T1296] INFO:   10000 queries parsed...
2026-03-01 09:23:54.491 UTC [1217/T1296] INFO:   20000 queries parsed...
2026-03-01 09:23:54.529 UTC [1217/T1296] INFO:   30000 queries parsed...
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO: Imported 38926 queries from the long-term database
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO:  -> Total DNS queries: 38927
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO:  -> Cached DNS queries: 27737
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO:  -> Forwarded DNS queries: 6036
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO:  -> Blocked DNS queries: 967
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO:  -> Unknown DNS queries: 0
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO:  -> Unique domains: 889
2026-03-01 09:23:54.561 UTC [1217/T1296] INFO:  -> Unique clients: 3
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: FTL commit: f8883098
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: FTL date: 2026-02-17 20:20:12 +0000
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: FTL user: started as pihole, ended as pihole
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: Compiled for linux/amd64 (compiled on CI) using cc (Alpine 15.2.0) 15.2.0
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: Process details: MID: 1217
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO:                  PID: 1217
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO:                  TID: 1296
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO:                  Name: database
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: Received signal: Segmentation fault
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO:      at address: 0x733d56b88000
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO:      with code:  SEGV_ACCERR (Invalid permissions for mapped object)
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: !!! INFO: pihole-FTL has not been compiled with glibc/backtrace support, not generating one !!!
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: ------ Listing content of directory /dev/shm ------
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: File Mode User:Group      Size  Filename
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rwxrwxrwx root:root       360   .
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rwxr-xr-x root:root         4k  ..
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole   768k  FTL-1217-recycler
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole     8k  FTL-1217-dns-cache-lookup
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole    12k  FTL-1217-domains-lookup
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole     4k  FTL-1217-clients-lookup
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole   555k  FTL-1217-fifo-log
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole     4k  FTL-1217-per-client-regex
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole    36k  FTL-1217-dns-cache
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole     8k  FTL-1217-overTime
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole     3M  FTL-1217-queries
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole    28k  FTL-1217-upstreams
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole   340k  FTL-1217-clients
2026-03-01 09:44:06.041 UTC [1217/T1296] INFO: rw------- pihole:pihole    36k  FTL-1217-domains
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: rw------- pihole:pihole    80k  FTL-1217-strings
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: rw------- pihole:pihole   144   FTL-1217-settings
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: rw------- pihole:pihole   344   FTL-1217-counters
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: rw------- pihole:pihole   120   FTL-1217-lock
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: ---------------------------------------------------
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: Please also include some lines from above the !!!!!!!!! header.
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: Thank you for helping us to improve our FTL engine!
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: Shutting down thread...
2026-03-01 09:44:06.042 UTC [1217/T1296] INFO: Asked to terminate by "/usr/bin/pihole-FTL -f" (PID 1217, user pihole UID 996)
2026-03-01 09:44:06.042 UTC [1217M] ERROR: Error when obtaining outer SHM lock: Previous owner died
2026-03-01 09:44:06.042 UTC [1217M] ERROR: Error when obtaining inner SHM lock: Previous owner died
2026-03-01 09:44:06.112 UTC [1217/T1298] INFO: Terminating resolver thread
2026-03-01 09:44:06.120 UTC [1217/T1299] INFO: Terminating timer thread
2026-03-01 09:44:06.149 UTC [1217/T1297] INFO: Terminating GC thread
2026-03-01 10:01:40.577 UTC [1217M] INFO: Asked to terminate by "/sbin/init" (PID 1, user root UID 0)

it will then restart after... however long it feels like and die
rebooting fixes it for a bit, then it crashes again

SEGV_MAPERR first time, SEGV_ACCERR thereafter until reboot

[DL6ER]

@ThisCatLikesCrypto could you try attaching the debugger as suggested here?

#2783 (comment)

[ThisCatLikesCrypto]

i ended up uninstalling and reverting to unbound, apologies
i have loads of exams coming up so i dont have time to reinstall this at the moment
if it's any help i was using unbound as backend and hadn't changed any configs from default
i did try disabling WAL eventually but that didn't fix it
ubuntu 24.04

[DL6ER]

Can we call this fixed or - rather - not able to reproduce any further? Because, without a backtrace, we cannot do much anything further on this. I recently wrote #2811 to ensure we get backtraces again in the binaries so hopefully this will be easier in the future.