Segmentation fault at address X

[kyng-cytro]

How can we reproduce the crash?

Unfortunately, the crash happens non-deterministically. I'm running a WebSocket server using Hono with Bun’s native HTTP and WebSocket APIs. The server can run fine for hours before crashing.

• WebSocket clients connect and send messages (up to dozens of concurrent connections)
• Each message may trigger internal logic
• The Bun process crashes spontaneously, with no consistent pattern
• Memory usage seems fine (~100–200MB)

Relevant log output

============================================================

Bun v1.2.19 (aad3abea) Linux x64 (baseline)

Linux Kernel v6.12.22 | musl

CPU: sse42 popcnt avx avx2 avx512

Args: "bun" "src/index.ts"

Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) abort_signal(144) fetch(82) http_server jsc spawn tsconfig(6) tsconfig_paths process_dlopen 

Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:os" "node:path" "node:process" "node:querystring" "node:stream" "node:string_decoder" "node:tty" "node:url" "node:util" "node:worker_threads" "node-fetch" "node:http2" "node:cluster" 

Elapsed: 14790663ms | User: 46461ms | Sys: 22095ms

RSS: 0.89GB | Peak: 0.14GB | Commit: 0.89GB | Faults: 86 | Machine: 8.00GB

 

panic: Segmentation fault at address 0x10

oh no: Bun has crashed. This indicates a bug in Bun, not your code.

 

To send a redacted crash report to Bun's team,

please file a GitHub issue using the link below:

 

 https://bun.report/1.2.19/Ba1aad3abewhBuhk0ggCu0t3rEA2AgB

 

error: script "start" was terminated by signal SIGILL (Illegal instruction)

$ bun src/index.ts

Stack Trace (bun.report)

Bun v1.2.19 (aad3abe) on linux x86_64_baseline [RunCommand]

Segmentation fault at address 0x000000A0

• RefCounted.h:137: JSC::OpSetFunctionName::dump

Features: process_dlopen, s3, Bun.stderr, Bun.stdin, Bun.stdout, fetch, http_server, jsc, spawn

_{Sentry Issue: BUN-RKT}

[linear]

ENG-19871 Segmentation fault at address X

[Jarred-Sumner]

@kyng-cytro are you using v8 heap snapshots by chance? i suspect it's a crash when reading function names inside of our v8 heap snapshots implementation

[kyng-cytro]

@Jarred-Sumner I’m not generating any heap snapshots myself unless Bun does it internally, I'm not using them.

[kyng-cytro]

Seems related to prisma/prisma#27785

[kyng-cytro]

Seems related to prisma/prisma#27785

The issue was due to a bug in OpenSSL 3.3.4, fixed in 3.5.2. However, oven/bun:1-alpine is based on alpine:3.20, which still ships OpenSSL 3.3.4

A proper fix would be to bump the Bun Alpine base image to 3.22 (and likely do the same for the Debian variant).