From 1f0707e8e78ef290fd0f229df3fcd2236f29db89 Mon Sep 17 00:00:00 2001
From: Changqing Li <changqing.li@windriver.com>
Date: Thu, 28 Oct 2021 11:11:05 +0800
Subject: [PATCH] upstream: need initgroups() before setresgid(); reported by
 anton@,

ok deraadt@

OpenBSD-Commit-ID: 6aa003ee658b316960d94078f2a16edbc25087ce

CVE: CVE-2021-41617
Upstream-Status: [Backport]
https://github.com/openssh/openssh-portable/commit/f3cbe43e28fe71427d41cfe3a17125b972710455
https://github.com/openssh/openssh-portable/commit/bf944e3794eff5413f2df1ef37cddf96918c6bde

Signed-off-by: Changqing Li <changqing.li@windriver.com>
---
 misc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/misc.c b/misc.c
index d988ce3..33eca1c 100644
--- a/misc.c
+++ b/misc.c
@@ -56,6 +56,7 @@
 #ifdef HAVE_PATHS_H
 # include <paths.h>
 #include <pwd.h>
+#include <grp.h>
 #endif
 #ifdef SSH_TUN_OPENBSD
 #include <net/if.h>
@@ -2629,6 +2630,13 @@ 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));
-- 
2.17.1

