Remote Write 2.0 panics with an incorrect symbols table #17149
Description
What did you do?
Ran an invalid query, with an empty symbols table
What did you expect to see?
HTTP 400
What did you see instead? Under which circumstances?
Prometheus panics
System information
Linux 6.15.8 x86_64
Prometheus version
prometheus, version 3.5.0 (branch: main, revision: 43c1535bdfdd6368d01513459cf5790af8b50f05)
build user: reproducible@reproducible
build date: 19800101-00:00:00
go version: go1.25.0
platform: linux/amd64
tags: netgo,builtinassets
Prometheus configuration file
Alertmanager version
Alertmanager configuration file
Logs
time=2025-09-05T12:08:20.981+02:00 level=ERROR source=server.go:3677 msg="http: panic serving [::1]:45162: runtime error: index out of range [15] with length 15\ngoroutine 721 [running]:\nnet/http
.(*conn).serve.func1()\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:1943 +0xd3\npanic({0x4fe0b20?, 0xc0018f40f0?})\n\t/nix/store/x322dk8vnsfbr9p31175zhq
cc9534iql-go-1.25.0/share/go/src/runtime/panic.go:783 +0x132\ngithub.com/prometheus/prometheus/web.(*Handler).Run.withStackTracer.func9.1()\n\t/home/roidelapluie/dev/prometheus/web/web.go:125 +0x1
d4\npanic({0x4fe0b20?, 0xc0018f40f0?})\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/runtime/panic.go:783 +0x132\ngithub.com/prometheus/prometheus/prompb/io/prometheus/writ
e/v2.desymbolizeLabels(0xc000df4710, {0xc0018f40d8, 0x6, 0x7?}, {0xc00023ad00, 0xf, 0x0?})\n\t/home/roidelapluie/dev/prometheus/prompb/io/prometheus/write/v2/symbols.go:79 +0x205\ngithub.com/prome
theus/prometheus/prompb/io/prometheus/write/v2.TimeSeries.ToLabels(...)\n\t/home/roidelapluie/dev/prometheus/prompb/io/prometheus/write/v2/codec.go:29\ngithub.com/prometheus/prometheus/storage/rem
ote.(*writeHandler).appendV2(0xc00062a960, {0x5e530c0, 0xc000198648}, 0xc00080c4b0, 0xc000df4b10)\n\t/home/roidelapluie/dev/prometheus/storage/remote/write_handler.go:391 +0x1db\ngithub.com/promet
heus/prometheus/storage/remote.(*writeHandler).writeV2(0xc00062a960, {0x5e34140?, 0xc000f1d650?}, 0xc00080c4b0)\n\t/home/roidelapluie/dev/prometheus/storage/remote/write_handler.go:353 +0x149\ngit
hub.com/prometheus/prometheus/storage/remote.(*writeHandler).ServeHTTP(0xc00062a960, {0x7fffb0c8aed8, 0xc00080c460}, 0xc0004d92c0)\n\t/home/roidelapluie/dev/prometheus/storage/remote/write_handler
.go:212 +0x725\ngithub.com/prometheus/prometheus/web/api/v1.(*API).remoteWrite(0xc000f1d6b0?, {0x7fffb0c8aed8?, 0xc00080c460?}, 0x47e49a?)\n\t/home/roidelapluie/dev/prometheus/web/api/v1/api.go:19
11 +0x32\ngithub.com/prometheus/prometheus/web.(*Handler).testReady-fm.(*Handler).testReady.func1({0x7fffb0c8aed8, 0xc00080c460}, 0xc0004d92c0)\n\t/home/roidelapluie/dev/prometheus/web/web.go:618
+0x11e\nnet/http.HandlerFunc.ServeHTTP(0x824f5d0?, {0x7fffb0c8aed8?, 0xc00080c460?}, 0x0?)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:2322 +0x29\ngith
ub.com/prometheus/client_golang/prometheus/promhttp.InstrumentHandlerResponseSize.func1({0x7fffb0c8aed8?, 0xc00080c410?}, 0xc0004d92c0)\n\t/home/roidelapluie/go/pkg/mod/github.com/prometheus/clien
[email protected]/prometheus/promhttp/instrument_server.go:296 +0xcf\nnet/http.HandlerFunc.ServeHTTP(0x7fffb12a1cc8?, {0x7fffb0c8aed8?, 0xc00080c410?}, 0xc000108808?)\n\t/nix/store/x322dk8vnsf
br9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:2322 +0x29\ngithub.com/prometheus/client_golang/prometheus/promhttp.InstrumentHandlerDuration.func2({0x7fffb0c8aed8, 0xc00080c410},
0xc0004d92c0)\n\t/home/roidelapluie/go/pkg/mod/github.com/prometheus/[email protected]/prometheus/promhttp/instrument_server.go:109 +0xc5\nnet/http.HandlerFunc.ServeHTTP(0x824f590?, {0x7f
ffb0c8aed8?, 0xc00080c410?}, 0xc0007492c8?)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:2322 +0x29\ngithub.com/prometheus/client_golang/prometheus/prom
http.InstrumentHandlerCounter.func1({0x5e243f0?, 0xc00120e480?}, 0xc0004d92c0)\n\t/home/roidelapluie/go/pkg/mod/github.com/prometheus/[email protected]/prometheus/promhttp/instrument_serv
er.go:147 +0xc3\ngithub.com/prometheus/prometheus/web.(*Handler).Run.setPathWithPrefix.func5.1({0x5e243f0, 0xc00120e480}, 0xc0004d9180)\n\t/home/roidelapluie/dev/prometheus/web/web.go:907 +0xb3\ng
ithub.com/prometheus/common/route.(*Router).handle.func1({0x5e243f0, 0xc00120e480}, 0xc0004d9040, {0x0, 0x0, 0x0?})\n\t/home/roidelapluie/go/pkg/mod/github.com/prometheus/[email protected]/route/rout
e.go:83 +0x1e9\ngithub.com/julienschmidt/httprouter.(*Router).ServeHTTP(0xc0006e8240, {0x5e243f0, 0xc00120e480}, 0xc0004d9040)\n\t/home/roidelapluie/go/pkg/mod/github.com/julienschmidt/httprouter@
v1.3.0/router.go:387 +0x815\ngithub.com/prometheus/common/route.(*Router).ServeHTTP(0x0?, {0x5e243f0?, 0xc00120e480?}, 0x7?)\n\t/home/roidelapluie/go/pkg/mod/github.com/prometheus/[email protected]/r
oute/route.go:126 +0x25\ngithub.com/prometheus/prometheus/web.(*Handler).Run.StripPrefix.func7({0x5e243f0, 0xc00120e480}, 0xc0004d8f00)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/sha
re/go/src/net/http/server.go:2384 +0x262\nnet/http.HandlerFunc.ServeHTTP(0xc000170000?, {0x5e243f0?, 0xc00120e480?}, 0xc000749698?)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/g
o/src/net/http/server.go:2322 +0x29\nnet/http.(*ServeMux).ServeHTTP(0x5e34140?, {0x5e243f0, 0xc00120e480}, 0xc0004d8f00)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/h
ttp/server.go:2861 +0x1c7\ngo.opentelemetry.io/contrib/instrumentation/net/http/otelhttp.(*middleware).serveHTTP(0xc0008c2000, {0x5e17a20, 0xc000d300f0}, 0xc0004d8b40, {0x5dd2980, 0xc000170000})\n
\t/home/roidelapluie/go/pkg/mod/go.opentelemetry.io/contrib/instrumentation/net/http/[email protected]/handler.go:180 +0x1303\ngo.opentelemetry.io/contrib/instrumentation/net/http/otelhttp.NewMiddl
eware.func1.1({0x5e17a20?, 0xc000d300f0?}, 0xc000930b28?)\n\t/home/roidelapluie/go/pkg/mod/go.opentelemetry.io/contrib/instrumentation/net/http/[email protected]/handler.go:67 +0x35\nnet/http.Handl
erFunc.ServeHTTP(0xc000628400?, {0x5e17a20?, 0xc000d300f0?}, 0xc000930b38?)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:2322 +0x29\ngithub.com/promethe
us/prometheus/web.(*Handler).Run.withStackTracer.func9({0x5e17a20?, 0xc000d300f0?}, 0x4bb953?)\n\t/home/roidelapluie/dev/prometheus/web/web.go:128 +0x6b\nnet/http.HandlerFunc.ServeHTTP(0x41d9e5?,
{0x5e17a20?, 0xc000d300f0?}, 0xc000d30001?)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:2322 +0x29\nnet/http.serverHandler.ServeHTTP({0x5de70f0?}, {0x5
e17a20?, 0xc000d300f0?}, 0x1?)\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:3340 +0x8e\nnet/http.(*conn).serve(0xc000df8240, {0x5e34140, 0xc0008ca0f0})\
n\t/nix/store/x322dk8vnsfbr9p31175zhqcc9534iql-go-1.25.0/share/go/src/net/http/server.go:2109 +0x665\ncreated by net/http.(*Server).Serve in goroutine 481\n\t/nix/store/x322dk8vnsfbr9p31175zhqcc95
34iql-go-1.25.0/share/go/src/net/http/server.go:3493 +0x485" component=web