fix(sshstdio): bound how long mux close waits for a lingering grandchild

commit: e77fed7b3908fbfc903ba2e5b378864c4e79493e
author: brice · 29d ago · 2026-09-23 21:37 UTC
parent: d2968dd
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

1 file · +5 -0

M internal/adapters/sshstdio/mux.go +5 -0


@@ -46,6 +46,7 @@ import (
46	46		"os/exec"
47	47		"strings"
48	48		"sync"
	49	+	"time"
49	50		"unicode"
50	51		"unicode/utf8"
51	52

@@ -166,6 +167,10 @@ func dialMuxContext(ctx context.Context, spec CommandSpec, logger *slog.Logger,
166	167		}
167	168		stderr := newCappedDiagnostic(muxStderrLimit)
168	169		cmd.Stderr = stderr
	170	+	// A grandchild (for example ssh's ProxyCommand) can outlive a killed
	171	+	// child and hold the stderr pipe open; bound how long Wait keeps copying
	172	+	// from it so Close never waits for that grandchild to exit.
	173	+	cmd.WaitDelay = time.Second
169	174		if err := cmd.Start(); err != nil {
170	175		_ = stdin.Close()
171	176		return nil, fmt.Errorf("sshstdio: mux start %s: %w", spec.Path, err)


@@ -46,6 +46,7 @@ import (
46	"os/exec"	46		"os/exec"
47	"strings"	47		"strings"
48	"sync"	48		"sync"
		49	+	"time"
49	"unicode"	50		"unicode"
50	"unicode/utf8"	51		"unicode/utf8"
51		52

@@ -166,6 +167,10 @@ func dialMuxContext(ctx context.Context, spec CommandSpec, logger *slog.Logger,
166	}	167		}
167	stderr := newCappedDiagnostic(muxStderrLimit)	168		stderr := newCappedDiagnostic(muxStderrLimit)
168	cmd.Stderr = stderr	169		cmd.Stderr = stderr
		170	+	// A grandchild (for example ssh's ProxyCommand) can outlive a killed
		171	+	// child and hold the stderr pipe open; bound how long Wait keeps copying
		172	+	// from it so Close never waits for that grandchild to exit.
		173	+	cmd.WaitDelay = time.Second
169	if err := cmd.Start(); err != nil {	174		if err := cmd.Start(); err != nil {
170	_ = stdin.Close()	175		_ = stdin.Close()
171	return nil, fmt.Errorf("sshstdio: mux start %s: %w", spec.Path, err)	176		return nil, fmt.Errorf("sshstdio: mux start %s: %w", spec.Path, err)