From 9b79efbe495f83a4f60990c5371a5a6454e99768 Mon Sep 17 00:00:00 2001
From: djm <djm@openbsd.org>
Date: Sun, 26 Sep 2021 14:01:03 +0000
Subject: [PATCH] need initgroups() before setresgid(); reported by anton@, ok
 deraadt@

---
 usr.bin/ssh/misc.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/usr.bin/ssh/misc.c b/usr.bin/ssh/misc.c
index 9a1c057f635..b5e52b675bc 100644
--- a/usr.bin/ssh/misc.c
+++ b/usr.bin/ssh/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.169 2021/08/09 23:47:44 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.170 2021/09/26 14:01:03 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005-2020 Damien Miller.  All rights reserved.
@@ -2594,6 +2594,12 @@ subprocess(const char *tag, const char *command,
 		}
 		closefrom(STDERR_FILENO + 1);
 
+		if (geteuid() == 0 &&
+		    initgroups(pw->pw_name, pw->pw_gid) == -1) {
+			error("%s: initgroups(%s, %u): %s", tag,
+			    pw->pw_name, (u_int)pw->pw_gid, strerror(errno));
+			_exit(1);
+		}
 		if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) {
 			error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid,
 			    strerror(errno));
-- 
2.20.1