From 5553fc44b444e97226379ec58ec3880b89d88de0 Mon Sep 17 00:00:00 2001
From: Erik Tate <erik.tate@goteleport.com>
Date: Tue, 19 Nov 2024 11:15:40 -0500
Subject: [PATCH] changing parker pdeathsig to KILL so to prevent possibility
 of leaking

---
 lib/srv/reexec.go       |  2 +-
 lib/srv/reexec_linux.go | 11 +++++++++++
 lib/srv/reexec_other.go |  2 ++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/lib/srv/reexec.go b/lib/srv/reexec.go
index da1d84afa9079..4fe1d42aaa8ec 100644
--- a/lib/srv/reexec.go
+++ b/lib/srv/reexec.go
@@ -1282,7 +1282,7 @@ func (o *osWrapper) newParker(ctx context.Context, credential syscall.Credential
 	}
 
 	// Perform OS-specific tweaks to the command.
-	reexecCommandOSTweaks(cmd)
+	parkerCommandOSTweaks(cmd)
 
 	if err := cmd.Start(); err != nil {
 		return trace.Wrap(err)
diff --git a/lib/srv/reexec_linux.go b/lib/srv/reexec_linux.go
index dcba0399ba1a8..26d7742dad210 100644
--- a/lib/srv/reexec_linux.go
+++ b/lib/srv/reexec_linux.go
@@ -82,6 +82,17 @@ func reexecCommandOSTweaks(cmd *exec.Cmd) {
 	}
 }
 
+// if we ever need to run parkers on macOS or other platforms with no PDEATHSIG
+// we should rework the parker to block on a pipe so it can exit when its parent
+// is terminated
+func parkerCommandOSTweaks(cmd *exec.Cmd) {
+	reexecCommandOSTweaks(cmd)
+
+	// parker processes can leak if their PDEATHSIG is SIGQUIT, otherwise we
+	// could just use reexecCommandOSTweaks
+	cmd.SysProcAttr.Pdeathsig = syscall.SIGKILL
+}
+
 func userCommandOSTweaks(cmd *exec.Cmd) {
 	if cmd.SysProcAttr == nil {
 		cmd.SysProcAttr = new(syscall.SysProcAttr)
diff --git a/lib/srv/reexec_other.go b/lib/srv/reexec_other.go
index c99e8e3cdac9e..d5f48d6999fb3 100644
--- a/lib/srv/reexec_other.go
+++ b/lib/srv/reexec_other.go
@@ -27,6 +27,8 @@ import (
 
 func reexecCommandOSTweaks(cmd *exec.Cmd) {}
 
+func parkerCommandOSTweaks(cmd *exec.Cmd) {}
+
 func userCommandOSTweaks(cmd *exec.Cmd) {}
 
 func setNeutralOOMScore() error { return nil }