sqlite, console, process: do not abort on a string too long to convert to UTF-8

[robobun]

Problem

• A string of 2^30 characters aborts the process when a call passes it to a C API: panic(main thread): abort() called, exit code 134, also inside try / catch. Debug builds print ASSERTION FAILED: expectedString. Example: bun -e 'try { console.count("q".repeat(2**30)) } catch {}'. Fuzzing found it.
• Cause: utf8() asserts that the conversion worked. Callers: 6 in bun:sqlite, 20 in node:sqlite, 6 console label hooks (ConsoleObject.cpp:63), 3 in the process credential functions (BunProcess.cpp:3369). UTF8View: throw instead of aborting when a string does not convert to UTF-8 #42798 left them as a follow-up.
• With nss-systemd the lookups abort at 4 MiB: Assertion '_nn_ <= ALLOCA_MAX' failed.

Fix

• New Bun::tryUTF8 for a const char* consumer throws RangeError: Out of memory instead. The 24 const char* sqlite sites use it. The node:sqlite parameter and function result use UTF8View::tryCreate, as bun:sqlite does.
• The console label functions pass a BunString, and Rust converts it with no such limit. console.takeHeapSnapshot never read its title, so it converts nothing now.
• A name that bun looks up (process.setuid, setgid, seteuid, setegid, setgroups, the initgroups group) throws ERR_UNKNOWN_CREDENTIAL at 8192 characters: an entry must fit in the 8192 byte lookup buffer. So does a name with a NUL. The initgroups user still passes through.
• Verified: test/js/bun/util/utf8-conversion-limit.test.ts (main aborts at the first new row). Also the console, sqlite and process suites.

Background

• A JSC string is Latin-1 or UTF-16. A C API takes NUL-terminated UTF-8, so it needs a copy.
• WTF reserves 2 bytes per Latin-1 character, and a buffer holds 2^31 - 1 bytes. So 2^30 characters fail, ASCII or not.
• UTF8View (UTF8View: throw instead of aborting when a string does not convert to UTF-8 #42798) borrows an ASCII string. It has no NUL terminator.
• NSS is the libc plug-in layer behind getpwnam_r. nss-systemd is one module.

Notes

Repro. Each line aborts alone with exit code 134 on main (553523ba8b), at 1.1 GB RSS. With this branch each one reports what the right column says.

const long = "q".repeat(2 ** 30);
const { Database } = require("bun:sqlite");
const { DatabaseSync, backup } = require("node:sqlite");
const db = new Database(":memory:");
const ndb = new DatabaseSync(":memory:", { allowExtension: true });

new Database(long);                       // RangeError: Out of memory
db.serialize(long);                       // same
db.fileControl(long, 10, 0);              // same
db.loadExtension(long);                   // same, and loadExtension("x", long)
new DatabaseSync(long);                   // same
ndb.exec(long); ndb.prepare(long);        // same
ndb.createTagStore().get([long]);         // same
ndb.location(long); ndb.serialize(long);  // same
ndb.deserialize(new Uint8Array(8), { dbName: long }); // same
ndb.function(long, () => 1);              // same, and aggregate(long, ...)
ndb.createSession({ db: long });          // same, and { table: long }
ndb.prepare("SELECT $a").get({ [long]: 1 }); // same (the parameter name)
backup(ndb, long);                        // same, and { source: long }, { target: long }
ndb.prepare("SELECT ?").get(long);        // SQLite gets the buffer: "string or blob too big"
console.count(long);                      // prints the label, 2^30 + 4 bytes
console.time(long); console.timeLog(long); console.timeEnd(long); console.countReset(long);
console.takeHeapSnapshot(long);           // takes the snapshot
process.setuid(long);                     // ERR_UNKNOWN_CREDENTIAL, also setgid, seteuid, setegid, setgroups, initgroups(0, long)
process.initgroups(long, 0);              // RangeError: Out of memory

A non-ASCII string ("\u00e9".repeat(2 ** 30)) gives RangeError: Out of memory for the node:sqlite parameter and for a function result, because UTF8View has to convert it. A 16-bit string of 715,827,883 x U+0800 (a UTF-8 form of 2^31 + 1 bytes) behaves the same as the Latin-1 one at every site. I checked that by hand.

Reach. No user reported this. A string of 2^30 equal characters is about 1 MiB as gzip. So await res.text() of a small response can produce one, and SQL text or a parameter built from it reaches node:sqlite.

The three policies.

• sqlite: a path, SQL text or a name is data, so it throws RangeError: Out of memory, as Throw instead of aborting when an ERR_* error message passes the string length limit #42202, process.execve: throw instead of aborting for a string past the string limits #42308 and UTF8View: throw instead of aborting when a string does not convert to UTF-8 #42798 do. SQLite's own limit is 1e9 bytes, so no string that fails here was usable. function() and aggregate() convert the name before they allocate the callback context, and createSession() converts both names before it creates the session, so the new throw leaks nothing. backup() converts its three strings in the synchronous part, where Node converts them too.
• console: deleted the title conversion in ConsoleObject::takeHeapSnapshot and the _chars / _len parameters of Bun__ConsoleObject__takeHeapSnapshot, which nothing read. The label functions are total now. An earlier draft ignored a label that does not convert. That was a silent no-op, and it was not needed: bun_core::String::to_utf8() converts into a Vec with no 2^31 limit and borrows an 8-bit ASCII label. For a label just under the old limit, WTF allocated a 2 GiB scratch buffer and a 1 GiB copy. Peak RSS for console.count of a 1 GiB label is now 1056 MB. Output for short labels is byte-identical to 1.4.3, lone surrogate (U+FFFD) and embedded NUL included. A new test pins that.
• credentials: getpwnam_r and getgrnam_r fill a caller buffer of 8192 bytes with the whole entry, name included. glibc answers ERANGE for an entry that does not fit, and the code already treats that as unknown. So str.length() >= sizeof(buf) changes no answer that a lookup could give. It keeps long names away from NSS modules. On a machine with passwd: files systemd, 1.4.3 aborts for process.setuid("q".repeat(4 * 1024 * 1024)) in dropin_user_record_by_name (src/shared/userdb-dropin.c:118), and for the group functions in dropin_group_record_by_name (:262). The initgroups user is different: it goes to initgroups(3) as it is, as in Node, and that path fills no buffer. On main it returns for every length from 8192 to 2^30 - 1 characters (I ran it as root), so its only abort is the conversion. It uses Bun::tryUTF8 and throws RangeError: Out of memory. An earlier revision bounded it too. Review pointed out that the bound proves nothing on that path, so it passes through again.
• NUL: getpwnam_r, getgrnam_r and initgroups(3) stop at a NUL. On main, as root, process.setuid("daemon\0suffix") returns 0 and the process runs as daemon. Node v26.3.0 does the same. An entry name has no NUL, so such a name cannot match: all six functions, and both arguments of initgroups, throw ERR_UNKNOWN_CREDENTIAL before the C call. REVIEW.md asks for this ("Reject embedded NULs in strings passed to C APIs"), and review raised it on these lines. The sqlite sites are not changed for NUL: bun:sqlite: reject paths containing null bytes #37006 and Reject paths with embedded null bytes in Bun.mmap, unix sockets, and bun:sqlite #38514 own the paths, and bun:sqlite handles a NUL in SQL text on purpose. The message still carries the name. If it passes String::MaxLength (a name near 2^31 characters) it is RangeError: Out of memory through MessageBuilder (Throw instead of aborting when an ERR_* error message passes the string length limit #42202). On main makeString would call CRASH() there, behind the utf8() abort.

Not in this PR. These abort the same way on main. I ran each one. They are in other subsystems, and each needs its own failure policy and test.

Call	Site	Owner
new CompressionStream("gzip").writable.getWriter().write(long)	JSCompressionStreamShared.cpp:148	follow-up
new WebSocket("ws://" + long + ":p@host/")	WebSocket.cpp:235, :603	follow-up
new Bun.Cookie("a", "b", { expires: long }), Bun.Cookie.parse("a=b; Expires=" + long)	JSCookie.cpp:62, Cookie.cpp:118, :124	follow-up
tls.setDefaultCACertificates([long])	NodeTLS.cpp:210	follow-up
Bun.secrets.get({ service: long, name })	JSSecrets.cpp:238	follow-up
Set-Cookie header write	CookieMap.cpp:20	#42237
process.execve	BunProcess.cpp:1976, :2019, :2023	#42308
digest, cipher and curve names, X509Certificate#checkIP	ncrypto.cpp and node/crypto/	#42780
process.title = long on Windows	BunProcess.cpp:4737	follow-up
Bun.WebView	src/runtime/webview/	follow-up

The other utf8() calls under src/jsc/bindings take a module name, a source URL or an assertion message, or sit in commented-out LOG lines.

console.takeHeapSnapshot has no test row. On main it fails exception check validation for any title (JSC__JSGlobalObject__generateHeapSnapshot has a ThrowScope that its Rust caller does not check), and the ASAN lane runs with validation on. #37070 and #30817 fix that. I checked console.takeHeapSnapshot("q".repeat(2 ** 30)) by hand: it prints the snapshot.

Test. All rows are in the merged utf8-conversion-limit.test.ts, in its existing 1 GiB child: 17 new rows always, 1 more on POSIX (process.initgroups), 6 more where SQLite has the session extension and extension loading, and 6 more when !isDebug. The macOS system SQLite has neither extension, so the test probes for them as node-sqlite.test.ts does. With main's src/, the child passes the 13 merged rows and aborts at new Database. Some rows scan or hash 1 GiB in code that a debug build does not optimize: 14 s per console label call, 28 s for console.count, 10 s for the property key. Those rows and the console.count test run only when !isDebug. I ran them on a release build of this branch: the file takes 7 s, and console.count delivers exactly 2^30 + 4 bytes. The credential test needs no large string. Its 4 MiB rows fail on main only where nss-systemd is configured. Its NUL rows fail on main everywhere: the calls return or report EPERM, because the lookup finds daemon.

Suites run (debug ASAN build). utf8-conversion-limit.test.ts (also with BUN_JSC_validateExceptionChecks=1, leak detection and BUN_DESTRUCT_VM_ON_EXIT=1, which is the ASAN lane's environment), test/js/web/console/, sqlite.test.js, node-sqlite.test.ts, the 18 test-sqlite* node tests, test-process-euid-egid, -initgroups, -setgroups, -uid-gid, test-child-process-uid-gid, four test-console-* node tests, process.test.js. Two failures are not from this change. sqlite.test.js #13082 runs 99 x (100 ms sleep + 2 full GCs) and takes 7.6 s in a debug build against the 5 s limit. It passes in 265 ms on the release build of this branch. process.test.js process needs USER in the environment, which this container does not set.

Self-review: 8 concerns raised, 7 addressed, 1 rejected.

• Addressed: the credential sites still aborted at 4 MiB in nss-systemd. They have the length bound now, and no conversion check.
• Addressed: the node:sqlite parameter and function result take a pointer and a length. They use UTF8View, so an ASCII string reaches SQLite, as in bun:sqlite.
• Addressed: the console label functions ignored a label that does not convert. They convert in Rust now.
• Addressed: the branch changed generate_heap_snapshot() to make a takeHeapSnapshot test pass under validation. That is console.takeHeapSnapshot: report snapshot parse failures instead of aborting #37070's change. The hunk and the test are gone.
• Addressed: the test was a second file next to the merged one. The rows moved into the merged file.
• Addressed: the description said 23 node:sqlite sites. It is 20.
• Addressed: the rest of the class was not named. The table above names it, with a repro for each row.
• Rejected: split this into three PRs. The three parts share no code, but REVIEW.md asks for the whole class in one PR ("same-class sites are ONE concern"), and the excluded sites are listed.

Conflicts to expect. #42666 (WebKit upgrade) renames .data() on lines next to these. Bun::tryUTF8 returns the base WTF::CString, so its call sites keep .data(). #42780 and #42308 can use Bun::tryUTF8 in place of their local conversions after this lands.

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no test proof · iteration 1 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/bun/util/utf8-conversion-limit.test.ts

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Walkthrough

The changes add fallible UTF-8 conversion, update console label interfaces, apply conversion handling across SQLite and credential APIs, and expand tests for oversized, non-ASCII, NUL-containing, and short strings.

Changes

UTF-8 conversion and native API handling

Layer / File(s)	Summary
Fallible UTF-8 conversion contract src/jsc/bindings/BunString.*	Adds Bun::tryUTF8, which returns a UTF-8 copy and reports conversion allocation failure as RangeError: Out of memory.
Console string interface src/jsc/ConsoleObject.rs, src/jsc/bindings/ConsoleObject.cpp, src/jsc/bindings/headers.h	Console label parameters now use BunString values. takeHeapSnapshot no longer receives unused label arguments.
SQLite conversion paths src/jsc/bindings/sqlite/JSSQLStatement.cpp, src/jsc/bindings/sqlite/NodeSqlite.cpp	SQLite paths, SQL text, names, parameters, extensions, sessions, serialization, and backups now use fallible UTF-8 conversion before SQLite calls.
Credential bounds and conversion validation src/jsc/bindings/BunProcess.cpp, test/js/bun/util/utf8-conversion-limit.test.ts	Credential lookup names are bounded before lookup. Tests cover oversized and short strings across console, SQLite, credential, and related APIs.

Suggested reviewers: dylan-conway

Priority: ➖ Normal

Merge Risk: ⚪ Minimal · up to f431b

The credential paths do not retain the alleged abort or byte-limit defects, so the change is ready for normal merge checks.

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✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the main change: preventing aborts when very long strings are converted to UTF-8 in SQLite, console, and process APIs.
Description check	✅ Passed	The description provides a detailed problem statement, fix summary, scope, reproductions, testing details, failures, and out-of-scope items. It does not use the exact template headings, but it include…

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[robobun]

Status

This PR is ready for review and merge. The description has the full account.

CI. The diff is green on every lane of build 116327: 180 of 181 jobs passed. The one red job is the debian x64-asan shard that runs test/js/bun/http/serve-pending-promise-abort-leak.test.ts. That test fails on every attempt, it also fails in the final builds of other recently merged PRs, and this PR does not touch Bun.serve. It is reported as a break on main. The other failures in the build passed on a retry.

test/js/bun/util/utf8-conversion-limit.test.ts, which carries all the new rows, passed on each platform: debian, ubuntu and alpine (x64 and aarch64), debian x64-asan, macOS aarch64 and x64 (6 pass), Windows 2019 x64 and Windows 11 aarch64 (5 pass, and the POSIX-only credential test skips).

Review. All six review threads have a reply and are resolved. Both review bots report nothing blocking on the current head.

How I reproduced it. Each of the first five lines aborts alone on main with panic(main thread): abort() called, exit code 134, also inside try / catch:

bun -e 'try { console.count("q".repeat(2**30)) } catch {}'
bun -e 'try { new (require("bun:sqlite").Database)("q".repeat(2**30)) } catch {}'
bun -e 'try { new (require("node:sqlite").DatabaseSync)(":memory:").exec("q".repeat(2**30)) } catch {}'
bun -e 'try { process.setuid("q".repeat(2**30)) } catch {}'
# where /etc/nsswitch.conf has "passwd: files systemd", 4 MiB is enough:
bun -e 'try { process.setuid("q".repeat(4 * 1024 * 1024)) } catch {}'
# as root, this one does not abort: it prints 1, the uid of "daemon"
bun -e 'process.setuid("daemon\0suffix"); console.log(process.getuid())'

Proof. With src/ from main, bun test test/js/bun/util/utf8-conversion-limit.test.ts fails: the 1 GiB child passes the 13 rows that #42798 added and aborts at the first new row (new Database), and the console.count and credential tests fail too. With this branch the file passes on a debug ASAN build and on a release build.

[claude]

Nothing blocking. The comments below are optional suggestions. There is no need to push a fix for them before merging.

[robobun]

^{Updated 10:26 PM PT - Sep 15th, 2026}

❌ @robobun, your commit f431bff has 1 failures in Build #116327 (All Failures):

• test/js/bun/http/serve-pending-promise-abort-leak.test.ts - code 1 on 🐧 13 x64-asan

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🧪   To try this PR locally:

bunx bun-pr 42868

That installs a local version of the PR into your bun-42868 executable, so you can run:

bun-42868 --bun

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Actionable comments posted: 2

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Inline comments:
In `@src/jsc/bindings/BunProcess.cpp`:
- Line 3385: Reject embedded NUL characters before credential C-string calls in
maybe_uid_by_name, maybe_gid_by_name, and the string branch of
Process_functioninitgroups. Apply the validation to setuid/seteuid,
setgid/setegid/setgroups, and both initgroups string arguments, returning the
existing invalid-input/error path without invoking getpwnam_r, getgrnam_r, or
initgroups.

In `@test/js/bun/util/utf8-conversion-limit.test.ts`:
- Line 131: Replace the repetitive string construction at
test/js/bun/util/utf8-conversion-limit.test.ts lines 131, 241, and 376 with
Buffer.alloc(count, fill).toString(), preserving each existing count and fill
character. Update the ASCII fixture, child fixture label, and credential name;
make no other changes.

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• src/jsc/bindings/ConsoleObject.cpp
• src/jsc/bindings/headers.h
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• src/jsc/bindings/sqlite/NodeSqlite.cpp
• test/js/bun/util/utf8-conversion-limit.test.ts

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[claude]

Code review completed

Nothing new to post: everything this review found is already covered by existing comments on this pull request or didn't merit a separate one.

[claude]

No new blocking issues. 1 optional suggestion (a nit or a note on pre-existing code) was found and not posted. Nothing in this review needs a push before merging.