Bug 285466 – WASM out-of-bounds exception running pglite when IPInt is enabled

• Component: JavaScriptCore
• Status: RESOLVED DUPLICATE

Created attachment 473811 [details]
Script to run pglite

When IPInt is enabled, initializing pglite (a distribution of PostgreSQL compiled to WASM) throws an out-of-bounds memory access exception.

Steps to reproduce:

1) Visit https://pglite.dev and scroll to the "Try PGLite Now" heading
2) Wait for the "SELECT * FROM now();" query to finish typing

Actual Results: the error "Out of bounds memory access (evaluating 'getWasmTableEntry(ue)(I,$n,Yn,Xn,Zn,rr)')" is displayed

Expected Results: a table with the current timestamp is displayed

Build Date : 2025-01-06 (commit faa4b20a62f299f89f135366fcaafc1e181e0122)
Hardware: MacBook Pro M3 Max, macOS 15.1.1

Additional Info:

I used a local debug build of WebKit from commit faa4b20a62f299f89f135366fcaafc1e181e0122 and the run-safari script to reproduce this. However, it didn't seem like the run-safari script was respecting the option to disable IPInt: I got the same exception using the command `JSC_useWasmIPInt=false ./Tools/Scripts/run-safari --debug`. I haven't used this script before so I might not be specifying options the right way.

To verify this is related to IPInt, you can also reproduce this issue on a canary build of the Bun runtime, where I'm definitely able to disable IPInt:

1) Install Bun (https://bun.sh)
2) Switch to a canary build: bun upgrade --canary
3) Download the attached JS file to a new directory, run `bun init -y`, and run `bun add @electric-sql/pglite`
4) Run the script with the default options (IPInt enabled): `bun index.js`
5) Run the script with IPInt disabled: `BUN_JSC_useWasmIPInt=false bun index.js`

Actual Results:

$ bun index.js
RuntimeError: Out of bounds memory access (evaluating 'this.mod._pg_initdb()')
      at <?>.wasm-function[10920]
      at <?>.wasm-function[8539]
      at <?>.wasm-function[5679]
      at <?>.wasm-function[4575]
      at <?>.wasm-function[2877]
      at /Users/ben/code/pglite/node_modules/@electric-sql/pglite/dist/index.js:3:2428652
$ BUN_JSC_useWasmIPInt=false bun index.js
2025-01-06T21:32:46.734Z

Expected Results: both commands print the timestamp

To reproduce with Bun canary you should also specify `BUN_JSC_useWasmIPInt=true` to make sure IPInt is enabled, rather than leaving that setting unspecified, as the next canary build will have IPInt disabled by default.

[Radar WebKit Bug Importer]

<rdar://problem/142442255>

[Alexey Proskuryakov]

Thank you for the report. I'm told that this was fixed as part of bug 285547.

*** This bug has been marked as a duplicate of bug 285547 ***

Thank you! Seems fixed on my end too.