From 1440742a1ce375dbc3da9fb67680328bbf06b73e Mon Sep 17 00:00:00 2001
From: Maisem Ali <maisem@tailscale.com>
Date: Tue, 1 Nov 2022 16:15:16 +0500
Subject: [PATCH] ssh/tailssh: use root / as cmd.Dir when users HomeDir doesn't
 exist

Fixes #5224

Signed-off-by: Maisem Ali <maisem@tailscale.com>
---
 ssh/tailssh/incubator.go | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/ssh/tailssh/incubator.go b/ssh/tailssh/incubator.go
index 86f7b835d..f0c12436c 100644
--- a/ssh/tailssh/incubator.go
+++ b/ssh/tailssh/incubator.go
@@ -283,7 +283,16 @@ func (ss *sshSession) launchProcess() error {
 	ss.cmd = ss.newIncubatorCommand()
 
 	cmd := ss.cmd
-	cmd.Dir = ss.conn.localUser.HomeDir
+	homeDir := ss.conn.localUser.HomeDir
+	if _, err := os.Stat(homeDir); err == nil {
+		cmd.Dir = homeDir
+	} else if os.IsNotExist(err) {
+		// If the home directory doesn't exist, we can't chdir to it.
+		// Instead, we'll chdir to the root directory.
+		cmd.Dir = "/"
+	} else {
+		return err
+	}
 	cmd.Env = append(cmd.Env, envForUser(ss.conn.localUser)...)
 	for _, kv := range ss.Environ() {
 		if acceptEnvPair(kv) {