From 4f092bee9fd818de4248f420388bf2d6eacea987 Mon Sep 17 00:00:00 2001
From: Martin Pool <mbp@samba.org>
Date: Sat, 9 Feb 2002 02:18:42 +0000
Subject: [PATCH] Make sure we call setgroups() after setuid().  (Ethan Benson)

---
 NEWS           |  5 +++++
 clientserver.c | 10 ++++++++++
 configure.in   |  2 +-
 log.c          |  2 ++
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 8c54134c..0d1fc6a4 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,10 @@
 rsync 2.5.3 (not released yet)
 
+  SECURITY FIXES:
+
+    * Make sure that supplementary groups are removed from a server
+      process after changing uid and gid. (Ethan Benson)
+
   ENHANCEMENTS:
 
     * Command to initiate connections is only shown with -vv, rather
diff --git a/clientserver.c b/clientserver.c
index 87e79908..6f3edfa9 100644
--- a/clientserver.c
+++ b/clientserver.c
@@ -294,6 +294,16 @@ static int rsync_module(int fd, int i)
 			return -1;
 		}
 
+#ifdef HAVE_SETGROUPS
+		/* Get rid of any supplementary groups this process
+		 * might have inheristed. */
+		if (setgroups(0, NULL)) {
+			rsyserr(FERROR, errno, "setgroups failed");
+			io_printf(fd, "@ERROR: setgroups failed\n");
+			return -1;
+		}
+#endif
+
 		am_root = (getuid() == 0);
 	}
 
diff --git a/configure.in b/configure.in
index 94565216..5eb0f777 100644
--- a/configure.in
+++ b/configure.in
@@ -351,7 +351,7 @@ AC_FUNC_UTIME_NULL
 AC_CHECK_FUNCS(waitpid wait4 getcwd strdup strerror chown chmod mknod)
 AC_CHECK_FUNCS(fchmod fstat strchr readlink link utime utimes strftime)
 AC_CHECK_FUNCS(memmove lchown vsnprintf snprintf asprintf setsid glob strpbrk)
-AC_CHECK_FUNCS(strlcat strlcpy mtrace mallinfo)
+AC_CHECK_FUNCS(strlcat strlcpy mtrace mallinfo setgroups)
 
 AC_CACHE_CHECK([for working socketpair],rsync_cv_HAVE_SOCKETPAIR,[
 AC_TRY_RUN([
diff --git a/log.c b/log.c
index f07b64b1..532803f2 100644
--- a/log.c
+++ b/log.c
@@ -342,6 +342,8 @@ void rsyserr(enum logcode code, int errcode, const char *format, ...)
 	len = vsnprintf(buf, sizeof(buf), format, ap);
 	va_end(ap);
 
+	/* TODO: Put in RSYNC_NAME at the start. */
+
 	if ((size_t) len > sizeof(buf)-1)
 		exit_cleanup(RERR_MESSAGEIO);
 
-- 
2.34.1