std: fix unix socket address truncation without a trailing NUL by devnexen · Pull Request #160416 · rust-lang/rust

devnexen · 2026-08-03T05:56:55Z

getsockname(2) and friends do not count the trailing NUL in the length they report on freebsd, netbsd and qnx, and a caller may bind(2) without one anywhere, so shortening the path by one byte dropped its last character. scan for the NUL within the reported length instead, which is the rule unix(7) gives and subsumes the qnx case the old cfg handled.

Fixes #118925

rustbot · 2026-08-03T05:57:00Z

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getsockname(2) and friends do not count the trailing NUL in the length they report on freebsd, netbsd and qnx, and a caller may bind(2) without one anywhere, so shortening the path by one byte dropped its last character. scan for the NUL within the reported length instead, which is the rule unix(7) gives and subsumes the qnx case the old cfg handled. Fixes rust-lang#118925

rustbot · 2026-08-03T05:58:12Z

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jhpratt · 2026-08-05T07:25:19Z

I'm unfamiliar with this level of OS detail.

@rustbot reroll

Mark-Simulacrum · 2026-08-08T22:43:16Z

-                if cfg!(any(target_os = "qnx", target_env = "nto71")) { len } else { len - 1 };
+            // linux adds a trailing NUL and counts it in the length, freebsd, netbsd
+            // and qnx do not, and a caller may bind(2) without one either. unix(7)
+            // gives the portable rule: strnlen(sun_path, len - offsetof(sun_path))


Should this also adjust

rust/library/std/src/os/unix/net/addr.rs

Lines 57 to 63 in 771916f

// on QNX7.1 and QNX8 the `len` value returned by the SUN_LEN

// macro in its libc does not include the null byte in the count so

// don't add it here to match what a C program passes to bind(2) and

// similar functions

if cfg!(not(any(target_os = "qnx", target_env = "nto71"))) {

len += 1

}

? Haven't traced the code but went looking for the QNX modifications which were in #158697.

View changes since the review

no because only the inbound one was a parsing bug, "oddly" enough QNX has it right using len (because this platform excludes the NULL terminator). As for the 'cfg' part, it is still needed as len is fed to bind where SUN_LEN for QNX is a real kernel-facing difference.

@rustbot ready

Mark-Simulacrum · 2026-08-16T17:20:05Z

@bors r+

rust-bors · 2026-08-16T17:20:08Z

📌 Commit e96993c has been approved by Mark-Simulacrum

It is now in the queue for this repository.

std: fix unix socket address truncation without a trailing NUL getsockname(2) and friends do not count the trailing NUL in the length they report on freebsd, netbsd and qnx, and a caller may bind(2) without one anywhere, so shortening the path by one byte dropped its last character. scan for the NUL within the reported length instead, which is the rule unix(7) gives and subsumes the qnx case the old cfg handled. Fixes rust-lang#118925

…uwer Rollup of 17 pull requests Successful merges: - #160529 (Upgrade and deduplicate dependencies) - #161017 (Library: enforce clippy deref lints in CI) - #160416 (std: fix unix socket address truncation without a trailing NUL) - #161006 ([CI] Build newer `binutils` before building `gcc`) - #161141 (Add documentation for BPF targets) - #161157 (bootstrap: Move several items out of the crate root) - #161185 (std: guard against unwinds in queue-based `Once`) - #161186 (miri subtree update) - #159855 (std: retry waitid on EINTR in the pidfd wait path) - #161053 (Add regression test for borrow of array drop type in const) - #161073 (Add regression test for path printing with infinitely many visible names) - #161099 (Add regression test for unstable def_ident_span fingerprint with incremental recompilation) - #161103 (cleanup: rip out unnecessary `iter().last()` and `iter().next()`) - #161136 (Add BPF test for Rust ABI stack arguments) - #161146 (Switch to c8a EC2 runner for auto merges) - #161148 ([rustdoc] Put back one removed flaky GUI test (which hopefully isn't flaky anymore)) - #161181 (Add back flaky gui rustdoc test `tests/rustdoc-gui/headers-color.goml`)

std: fix unix socket address truncation without a trailing NUL getsockname(2) and friends do not count the trailing NUL in the length they report on freebsd, netbsd and qnx, and a caller may bind(2) without one anywhere, so shortening the path by one byte dropped its last character. scan for the NUL within the reported length instead, which is the rule unix(7) gives and subsumes the qnx case the old cfg handled. Fixes rust-lang#118925

…uwer Rollup of 17 pull requests Successful merges: - #161017 (Library: enforce clippy deref lints in CI) - #160416 (std: fix unix socket address truncation without a trailing NUL) - #161006 ([CI] Build newer `binutils` before building `gcc`) - #161141 (Add documentation for BPF targets) - #161157 (bootstrap: Move several items out of the crate root) - #161185 (std: guard against unwinds in queue-based `Once`) - #161186 (miri subtree update) - #159855 (std: retry waitid on EINTR in the pidfd wait path) - #160478 (diagnostics: Suggest fn binding type for unstable closure for<> binders) - #161053 (Add regression test for borrow of array drop type in const) - #161073 (Add regression test for path printing with infinitely many visible names) - #161099 (Add regression test for unstable def_ident_span fingerprint with incremental recompilation) - #161103 (cleanup: rip out unnecessary `iter().last()` and `iter().next()`) - #161136 (Add BPF test for Rust ABI stack arguments) - #161146 (Switch to c8a EC2 runner for auto merges) - #161148 ([rustdoc] Put back one removed flaky GUI test (which hopefully isn't flaky anymore)) - #161181 (Add back flaky gui rustdoc test `tests/rustdoc-gui/headers-color.goml`)

Rollup merge of #160416 - devnexen:gh118925, r=Mark-Simulacrum std: fix unix socket address truncation without a trailing NUL getsockname(2) and friends do not count the trailing NUL in the length they report on freebsd, netbsd and qnx, and a caller may bind(2) without one anywhere, so shortening the path by one byte dropped its last character. scan for the NUL within the reported length instead, which is the rule unix(7) gives and subsumes the qnx case the old cfg handled. Fixes #118925

…uwer Rollup of 17 pull requests Successful merges: - rust-lang/rust#161017 (Library: enforce clippy deref lints in CI) - rust-lang/rust#160416 (std: fix unix socket address truncation without a trailing NUL) - rust-lang/rust#161006 ([CI] Build newer `binutils` before building `gcc`) - rust-lang/rust#161141 (Add documentation for BPF targets) - rust-lang/rust#161157 (bootstrap: Move several items out of the crate root) - rust-lang/rust#161185 (std: guard against unwinds in queue-based `Once`) - rust-lang/rust#161186 (miri subtree update) - rust-lang/rust#159855 (std: retry waitid on EINTR in the pidfd wait path) - rust-lang/rust#160478 (diagnostics: Suggest fn binding type for unstable closure for<> binders) - rust-lang/rust#161053 (Add regression test for borrow of array drop type in const) - rust-lang/rust#161073 (Add regression test for path printing with infinitely many visible names) - rust-lang/rust#161099 (Add regression test for unstable def_ident_span fingerprint with incremental recompilation) - rust-lang/rust#161103 (cleanup: rip out unnecessary `iter().last()` and `iter().next()`) - rust-lang/rust#161136 (Add BPF test for Rust ABI stack arguments) - rust-lang/rust#161146 (Switch to c8a EC2 runner for auto merges) - rust-lang/rust#161148 ([rustdoc] Put back one removed flaky GUI test (which hopefully isn't flaky anymore)) - rust-lang/rust#161181 (Add back flaky gui rustdoc test `tests/rustdoc-gui/headers-color.goml`)

rustbot assigned jhpratt Aug 3, 2026

rustbot added O-unix Operating system: Unix-like S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Aug 3, 2026

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devnexen force-pushed the gh118925 branch from 177f5d5 to e96993c Compare August 3, 2026 05:58

rustbot assigned Mark-Simulacrum and unassigned jhpratt Aug 5, 2026

Mark-Simulacrum reviewed Aug 8, 2026

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Mark-Simulacrum added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 8, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Aug 15, 2026

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JonathanBrouwer mentioned this pull request Aug 16, 2026

Rollup of 17 pull requests #161188

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This was referenced Aug 16, 2026

Rollup of 16 pull requests #161189

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Rollup of 17 pull requests #161196

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rust-bors Bot merged commit 71b938c into rust-lang:main Aug 17, 2026
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rustbot added this to the 1.100.0 milestone Aug 17, 2026

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std: fix unix socket address truncation without a trailing NUL - #160416

std: fix unix socket address truncation without a trailing NUL#160416
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devnexen:gh118925

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edited by Mark-Simulacrum

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	// on QNX7.1 and QNX8 the `len` value returned by the SUN_LEN
	// macro in its libc does not include the null byte in the count so
	// don't add it here to match what a C program passes to bind(2) and
	// similar functions
	if cfg!(not(any(target_os = "qnx", target_env = "nto71"))) {
	len += 1
	}

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