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. Log:

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

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 IST [17006M] INFO: FTL branch: master
2026-02-22 15:35:00.835 IST [17006M] INFO: FTL version: v6.5
2026-02-22 15:35:00.835 IST [17006M] INFO: FTL commit: f8883098
2026-02-22 15:35:00.835 IST [17006M] INFO: FTL date: 2026-02-17 20:20:12 +0000
2026-02-22 15:35:00.835 IST [17006M] INFO: FTL user: pihole
2026-02-22 15:35:00.835 IST [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 IST [17006M] INFO: Wrote config file:
2026-02-22 15:35:00.842 IST [17006M] INFO:  - 166 total entries
2026-02-22 15:35:00.842 IST [17006M] INFO:  - 135 entries are default
2026-02-22 15:35:00.842 IST [17006M] INFO:  - 31 entries are modified
2026-02-22 15:35:00.842 IST [17006M] INFO:  - 0 entries are forced through environment
2026-02-22 15:35:00.848 IST [17006M] INFO: Parsed config file /etc/pihole/pihole.toml successfully
2026-02-22 15:35:00.849 IST [17006M] INFO: PID file does not exist or not readable
2026-02-22 15:35:00.849 IST [17006M] INFO: No other running FTL process found.
2026-02-22 15:35:00.852 IST [17006M] INFO: PID of FTL process: 17006
2026-02-22 15:35:00.854 IST [17006M] INFO: listening on 0.0.0.0 port 53
2026-02-22 15:35:00.855 IST [17006M] INFO: listening on :: port 53
2026-02-22 15:35:00.860 IST [17009M] INFO: PID of FTL process: 17009
2026-02-22 15:35:00.864 IST [17009M] INFO: Database version is 21
2026-02-22 15:35:00.865 IST [17009M] INFO: Database successfully initialized
2026-02-22 15:35:01.194 IST [17009M] INFO: NTP sync is disabled
2026-02-22 15:35:01.196 IST [17009M] INFO: FTL is running as user pihole (UID 115)
2026-02-22 15:35:01.196 IST [17009/T17047] INFO: Reading certificate from /etc/pihole/tls.pem ...
2026-02-22 15:35:01.198 IST [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 IST [17009M] INFO: Blocking status is enabled
2026-02-22 15:35:01.199 IST [17009/T17047] INFO: Using SSL/TLS certificate file /etc/pihole/tls.pem
2026-02-22 15:35:01.203 IST [17009/T17047] INFO: Web server ports:
2026-02-22 15:35:01.203 IST [17009/T17047] INFO:   - 0.0.0.0:53080 (HTTP, IPv4, optional, OK)
2026-02-22 15:35:01.203 IST [17009/T17047] INFO:   - 0.0.0.0:53443 (HTTPS, IPv4, optional, OK)
2026-02-22 15:35:01.203 IST [17009/T17047] INFO:   - [::]:53080 (HTTP, IPv6, optional, OK)
2026-02-22 15:35:01.203 IST [17009/T17047] INFO:   - [::]:53443 (HTTPS, IPv6, optional, OK)
2026-02-22 15:35:03.738 IST [17009/T17043] INFO: Imported 48662 queries from the on-disk database (it has 76077 rows)
2026-02-22 15:35:03.738 IST [17009/T17047] INFO: Restored 1 API session from the database
2026-02-22 15:35:03.738 IST [17009/T17043] INFO: Parsing queries in database
2026-02-22 15:35:03.950 IST [17009/T17043] INFO:   10000 queries parsed...
2026-02-22 15:35:04.193 IST [17009/T17043] INFO:   20000 queries parsed...
2026-02-22 15:35:04.570 IST [17009/T17043] INFO:   30000 queries parsed...
2026-02-22 15:35:04.720 IST [17009/T17043] INFO:   40000 queries parsed...
2026-02-22 15:35:04.824 IST [17009/T17043] INFO: Imported 48662 queries from the long-term database
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Total DNS queries: 48749
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Cached DNS queries: 12355
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Forwarded DNS queries: 4119
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Blocked DNS queries: 31905
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Unknown DNS queries: 0
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Unique domains: 757
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Unique clients: 182
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> DNS cache records: 1121
2026-02-22 15:35:04.825 IST [17009/T17043] INFO:  -> Known forward destinations: 1
2026-02-22 15:35:06.708 IST [17009/T17043] INFO: Compiled 4 allow and 168 deny regex for 182 clients in 1878.9 msec
2026-02-22 15:35:08.722 IST [17009/T17045] ERROR: Cannot receive UDP DNS reply: Timeout - no response from upstream DNS server
2026-02-22 15:35:08.722 IST [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 IST [17009/T17045] ERROR: Cannot receive UDP DNS reply: Timeout - no response from upstream DNS server
2026-02-22 15:35:10.738 IST [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 IST [17009/T17045] ERROR: Cannot receive UDP DNS reply: Timeout - no response from upstream DNS server
2026-02-22 15:35:12.750 IST [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 IST [17009/T17043] INFO: Gravity database has been updated, reloading now
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: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2026-02-22 15:39:32.470 IST [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