Panic in MetricsProvider.sendMetrics (lpmetrics.go:389) - nil pointer dereference

[ngfblog]

What happened?

CrowdSec crashes with a panic in the LP metrics background goroutine (MetricsProvider.sendMetrics), introduced by the lp metrics feature (PR #2870 / #2858). Recurred multiple times over the past week. Full panic trace below:

error: runtime error: invalid memory address or nil pointer dereference
version: v1.7.8-6322745
BuildDate: 2026-06-17_18:09:57
GoVersion: 1.26.4
Platform: freebsd
goroutine 182 [running]:
runtime/debug.Stack()
runtime/debug/stack.go:26 +0x5e
github.com/crowdsecurity/go-cs-lib/trace.(*traceKeeper).writeStackTrace(0x4bd8da0, {0x4ecfc0, 0x4baacf0})
github.com/crowdsecurity/go-cs-lib@v0.0.25/trace/trace.go:165 +0x16e
github.com/crowdsecurity/go-cs-lib/trace.(*traceKeeper).handlePanic(0x4bd8da0, {0x0?, 0x4baa2e0?}, {0x4ecfc0, 0x4baacf0})
github.com/crowdsecurity/go-cs-lib@v0.0.25/trace/trace.go:180 +0x12f
github.com/crowdsecurity/go-cs-lib/trace.ReportPanic()
github.com/crowdsecurity/go-cs-lib@v0.0.25/trace/trace.go:48 +0x31
panic({0x4ecfc0?, 0x4baacf0?})
runtime/panic.go:860 +0x13a
main.(*MetricsProvider).sendMetrics(0x871ea4200, {0xa916d0?, 0x871f232c0?}, 0x871b343c0)
github.com/crowdsecurity/crowdsec/cmd/crowdsec/lpmetrics.go:389 +0xe8
main.(*MetricsProvider).Run(0x871ea4200, {0xa916d0, 0x871f232c0})
github.com/crowdsecurity/crowdsec/cmd/crowdsec/lpmetrics.go:411 +0x7c
main.startLPMetrics.func1()
github.com/crowdsecurity/crowdsec/cmd/crowdsec/crowdsec.go:121 +0x3c
created by main.startLPMetrics in goroutine 16
github.com/crowdsecurity/crowdsec/cmd/crowdsec/crowdsec.go:119 +0x105

What did you expect to happen?

CrowdSec should not panic/crash - the metrics goroutine should handle a nil value gracefully instead of crashing the whole service.

How can we reproduce it (as minimally and precisely as possible)?

Not reliably reproducible on demand. Observed correlation: an unrelated pfSense process (check_reload_status) was pinned at 100% CPU for ~10 minutes immediately before this crash occurred, possibly following a WAN interface flap. Suggests the panic may be related to timing/resource contention during a reload cycle rather than a fixed input.

Anything else we need to know?

Setup: pfSense CE 2.8.1 (FreeBSD 15) running CrowdSec as one Log Processor, with a second remote Log Processor (separate Linux box) also reporting to this LAPI. LAPI listen address is non-default (bound to LAN IP, not 127.0.0.1). Would appreciate a nil-check guard around whatever datasource/console-option lookup happens in sendMetrics at lpmetrics.go:389, and confirmation whether this is already fixed in a later version.

Crowdsec version

Details

$ cscli version
version: v1.7.8-6322745
Codename: alphaga
BuildDate: 2026-06-17_18:15:38
GoVersion: 1.26.4
Platform: freebsd
libre2: WebAssembly
User-Agent: crowdsec/v1.7.8-6322745-freebsd
Constraint_parser: >= 1.0, <= 3.0
Constraint_scenario: >= 1.0, <= 3.0
Constraint_api: v1
Constraint_acquis: >= 1.0, < 2.0
Built-in optional components: cscli_setup, datasource_appsec, datasource_cloudwatch, datasource_docker, datasource_file, datasource_http, datasource_journalctl, datasource_k8s-audit, datasource_kafka, datasource_kinesis, datasource_loki, datasource_s3, datasource_syslog, datasource_victorialogs, datasource_wineventlog, db_mysql, db_postgres, db_sqlite

OS version

Details

$ uname -a
FreeBSD pfSense-Dell.local 15.0-CURRENT FreeBSD 15.0-CURRENT #21 RELENG_2_8_1-n256095-47c932dcc0e9: Thu Aug 28 16:27:48 UTC 2025     root@pfsense-build-release-amd64-1.eng.atx.netgate.com:/var/jenkins/workspace/pfSense-CE-snapshots-2_8_1-main/obj/amd64/AupY3aTL/var/jenkins/workspace/pfSense-CE-snapshots-2_8_1-main/sources/FreeBSD-src-RELENG_2_8_1/amd64.amd64/sys/pfSense amd64

pfSense CE 2.8.1

Enabled collections and parsers

Details

$ cscli hub list -o raw
firewallservices/pf is tainted by scenarios:firewallservices/pf-scan-multi_ports
crowdsecurity/pfsense is tainted by collections:firewallservices/pf
Loaded: 165 parsers, 12 postoverflows, 784 scenarios, 9 contexts, 5 appsec-configs, 222 appsec-rules, 165 collections
Unmanaged items: 0 local, 3 tainted
name,status,version,description,type
crowdsecurity/dateparse-enrich,enabled,0.2,,parsers
crowdsecurity/geoip-enrich,enabled,0.5,"Populate event with geoloc info : as, country, coords, source range.",parsers
crowdsecurity/http-logs,enabled,1.3,"Parse more Specifically HTTP logs, such as HTTP Code, HTTP path, HTTP args and if its a static ressource",parsers
crowdsecurity/nginx-logs,enabled,2.0,Parse nginx access and error logs,parsers
crowdsecurity/pfsense-gui-logs,enabled,0.1,Parse pfSense web auth logs,parsers
crowdsecurity/public-dns-allowlist,enabled,0.1,Allow events from public DNS servers,parsers
crowdsecurity/sshd-logs,enabled,3.1,Parse openSSH logs,parsers
crowdsecurity/sshd-success-logs,enabled,0.1,Parse successful ssh logins,parsers
crowdsecurity/syslog-logs,enabled,1.0,,parsers
crowdsecurity/whitelists,enabled,0.3,Whitelist events from private ipv4 addresses,parsers
firewallservices/pf-logs,enabled,0.8,Parse packet filter logs,parsers
crowdsecurity/cdn-whitelist,enabled,0.5,Whitelist CDN providers,postoverflows
crowdsecurity/google-special-crawlers-whitelist,enabled,0.1,"Whitelist events from Google special crawlers (e.g. Google-InspectionTool, GoogleOther)",postoverflows
crowdsecurity/rdns,enabled,0.4,Lookup the DNS associated to the source IP only for overflows,postoverflows
crowdsecurity/seo-bots-whitelist,enabled,0.5,Whitelist good search engine crawlers,postoverflows
crowdsecurity/apache_log4j2_cve-2021-44228,enabled,0.7,Detect cve-2021-44228 exploitation attempts,scenarios
crowdsecurity/ban-defcon-drop_range,enabled,0.2,Ban a range if more than 5 ips from it are banned at a time,scenarios
crowdsecurity/CVE-2017-9841,enabled,0.2,Detect CVE-2017-9841 exploits,scenarios
crowdsecurity/CVE-2019-18935,enabled,0.2,Detect Telerik CVE-2019-18935 exploitation attempts,scenarios
crowdsecurity/CVE-2022-26134,enabled,0.4,Confluence - RCE (CVE-2022-26134),scenarios
crowdsecurity/CVE-2022-35914,enabled,0.2,Detect CVE-2022-35914 exploits,scenarios
crowdsecurity/CVE-2022-37042,enabled,0.2,Detect CVE-2022-37042 exploits,scenarios
crowdsecurity/CVE-2022-40684,enabled,0.3,Detect cve-2022-40684 exploitation attempts,scenarios
crowdsecurity/CVE-2022-41082,enabled,0.4,Detect CVE-2022-41082 exploits,scenarios
crowdsecurity/CVE-2022-41697,enabled,0.2,Detect CVE-2022-41697 enumeration,scenarios
crowdsecurity/CVE-2022-42889,enabled,0.3,Detect CVE-2022-42889 exploits (Text4Shell),scenarios
crowdsecurity/CVE-2022-44877,enabled,0.4,Detect CVE-2022-44877 exploits,scenarios
crowdsecurity/CVE-2022-46169,enabled,0.2,Detect CVE-2022-46169 brute forcing,scenarios
crowdsecurity/CVE-2023-22515,enabled,0.1,Detect CVE-2023-22515 exploitation,scenarios
crowdsecurity/CVE-2023-22518,enabled,0.3,Detect CVE-2023-22518 exploits,scenarios
crowdsecurity/CVE-2023-49103,enabled,0.3,Detect owncloud CVE-2023-49103 exploitation attempts,scenarios
crowdsecurity/CVE-2024-0012,enabled,0.1,Detect CVE-2024-0012 exploitation attempts,scenarios
crowdsecurity/CVE-2024-38475,enabled,0.1,Detect CVE-2024-38475 exploitation attempts,scenarios
crowdsecurity/CVE-2024-9474,enabled,0.1,Detect CVE-2024-9474 exploitation attempts,scenarios
crowdsecurity/f5-big-ip-cve-2020-5902,enabled,0.3,F5 BIG-IP TMUI - RCE (CVE-2020-5902),scenarios
crowdsecurity/fortinet-cve-2018-13379,enabled,0.4,Detect cve-2018-13379 exploitation attempts,scenarios
crowdsecurity/grafana-cve-2021-43798,enabled,0.3,Grafana - Arbitrary File Read (CVE-2021-43798),scenarios
crowdsecurity/http-admin-interface-probing,enabled,0.5,Detect generic HTTP admin interface probing,scenarios
crowdsecurity/http-backdoors-attempts,enabled,0.6,Detect attempt to common backdoors,scenarios
crowdsecurity/http-bad-user-agent,enabled,1.2,Detect usage of bad User Agent,scenarios
crowdsecurity/http-crawl-non_statics,enabled,0.7,Detect aggressive crawl on non static resources,scenarios
crowdsecurity/http-cve-2021-41773,enabled,0.3,Apache - Path Traversal (CVE-2021-41773),scenarios
crowdsecurity/http-cve-2021-42013,enabled,0.3,Apache - Path Traversal (CVE-2021-42013),scenarios
crowdsecurity/http-cve-probing,enabled,0.6,Detect generic HTTP cve probing,scenarios
crowdsecurity/http-generic-bf,enabled,0.9,Detect generic http brute force,scenarios
crowdsecurity/http-generic-test,enabled,0.2,Crowdsec Generic Test Scenario: basic HTTP trigger,scenarios
crowdsecurity/http-open-proxy,enabled,0.5,Detect scan for open proxy,scenarios
crowdsecurity/http-path-traversal-probing,enabled,0.4,Detect path traversal attempt,scenarios
crowdsecurity/http-probing,enabled,0.4,Detect site scanning/probing from a single ip,scenarios
crowdsecurity/http-sap-interface-probing,enabled,0.1,Detect generic HTTP SAP interface probing,scenarios
crowdsecurity/http-sensitive-files,enabled,0.4,"Detect attempt to access to sensitive files (.log, .db ..) or folders (.git)",scenarios
crowdsecurity/http-sqli-probing,enabled,0.4,A scenario that detects SQL injection probing with minimal false positives,scenarios
crowdsecurity/http-technology-probing,enabled,0.1,Detect HTTP technology/vendor probing,scenarios
crowdsecurity/http-wordpress-scan,enabled,0.4,Detect exploitation attempts against common WordPress endpoints,scenarios
crowdsecurity/http-xss-probing,enabled,0.4,A scenario that detects XSS probing with minimal false positives,scenarios
crowdsecurity/jira_cve-2021-26086,enabled,0.4,Detect Atlassian Jira CVE-2021-26086 exploitation attempts,scenarios
crowdsecurity/netgear_rce,enabled,0.4,Detect Netgear RCE DGN1000/DGN220 exploitation attempts,scenarios
crowdsecurity/nginx-req-limit-exceeded,enabled,0.3,Detects IPs which violate nginx's user set request limit.,scenarios
crowdsecurity/pfsense-gui-bf,enabled,0.2,Detect bruteforce on pfsense web interface,scenarios
crowdsecurity/pulse-secure-sslvpn-cve-2019-11510,enabled,0.4,Detect cve-2019-11510 exploitation attempts,scenarios
crowdsecurity/spring4shell_cve-2022-22965,enabled,0.3,Detect cve-2022-22965 probing,scenarios
crowdsecurity/ssh-bf,enabled,0.3,Detect ssh bruteforce,scenarios
crowdsecurity/ssh-cve-2024-6387,enabled,0.2,Detect exploitation attempt of CVE-2024-6387,scenarios
crowdsecurity/ssh-generic-test,enabled,0.2,Crowdsec Generic Test Scenario: SSH brute force trigger,scenarios
crowdsecurity/ssh-refused-conn,enabled,0.1,Detect sshd refused connections,scenarios
crowdsecurity/ssh-slow-bf,enabled,0.4,Detect slow ssh bruteforce,scenarios
crowdsecurity/ssh-time-based-bf,enabled,0.3,Detect time-based ssh bruteforce attempts that evade rate limiting (with false positive reduction),scenarios
crowdsecurity/thinkphp-cve-2018-20062,enabled,0.7,Detect ThinkPHP CVE-2018-20062 exploitation attempts,scenarios
crowdsecurity/vmware-cve-2022-22954,enabled,0.3,Detect Vmware CVE-2022-22954 exploitation attempts,scenarios
crowdsecurity/vmware-vcenter-vmsa-2021-0027,enabled,0.3,Detect VMSA-2021-0027 exploitation attempts,scenarios
firewallservices/pf-scan-multi_ports,"enabled,tainted",?,Detect aggressive portscans (pf),scenarios
ltsich/http-w00tw00t,enabled,0.3,detect w00tw00t,scenarios
crowdsecurity/bf_base,enabled,0.1,,contexts
crowdsecurity/firewall_base,enabled,0.2,,contexts
crowdsecurity/http_base,enabled,0.3,,contexts
crowdsecurity/base-http-scenarios,enabled,1.4,http common : scanners detection,collections
crowdsecurity/freebsd,enabled,0.5,core freebsd support : syslog+geoip+ssh,collections
crowdsecurity/http-cve,enabled,3.0,Detect CVE exploitation in http logs,collections
crowdsecurity/nginx,enabled,0.3,nginx support : parser and generic http scenarios,collections
crowdsecurity/pfsense,"enabled,tainted",0.3,core pfsense support,collections
crowdsecurity/pfsense-gui,enabled,0.2,pfSense web authentication support,collections
crowdsecurity/sshd,enabled,0.9,sshd support : parser and brute-force detection,collections
crowdsecurity/whitelist-good-actors,enabled,0.4,Good actors whitelists,collections
firewallservices/pf,"enabled,tainted",0.3,Parser and scenario for Packet Filter logs,collections

Acquisition config

Details

# On Linux:
$ cat /etc/crowdsec/acquis.yaml /etc/crowdsec/acquis.d/*
# paste output here

# On Windows:
C:\> Get-Content C:\ProgramData\CrowdSec\config\acquis.yaml
# paste output here

Config show

Details

$ cscli config show
# paste output here

Prometheus metrics

Details

$ cscli metrics
# paste output here

Related custom configs versions (if applicable) : notification plugins, custom scenarios, parsers etc.

Details

[github-actions]

@ngfblog: Thanks for opening an issue, it is currently awaiting triage.

In the meantime, you can:

1. Check Crowdsec Documentation to see if your issue can be self resolved.
2. You can also join our Discord.
3. Check Releases to make sure your agent is on the latest version.

Details

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[ngfblog]

Additional data point on this issue: I've now observed the panic occurring without any preceding check_reload_status CPU pin or interface flap.

Original occurrence (matches the reported pattern):

• ix2 link flap (DOWN→UP, 5s) at 11:00:45 → triggered rc.linkup/rc.newwanip → check_reload_status pinned at 100% CPU for ~10min → CrowdSec panic shortly after

New occurrence, ~65 minutes later (12:05:00), same day:

• grep -E "ix0|ix2" /var/log/system.log shows no interface events at all around this time — no flap, no rc.linkup, no rc.newwanip
• No check_reload_status stuck/killed alert from our watchdog around this window either
• CrowdSec panicked again with the identical trace (lpmetrics.go:389, MetricsProvider.sendMetrics, same v1.7.8-6322745 build)

This suggests the panic isn't strictly tied to reload-cycle resource contention — it may be a standalone race condition in the LP metrics goroutine that can fire independently (possibly just periodic timing, e.g. the metrics push interval hitting a nil datasource/console-option reference regardless of system load). Happy to share both crash trace files if useful.

Setup unchanged from the original report: pfSense CE 2.8.1, CrowdSec as one Log Processor with a second remote Log Processor (Linux) also reporting to this LAPI; non-default LAPI listen address (bound to LAN IP).