From: Karel Zak <kzak@redhat.com>
Date: Thu, 29 Jul 2021 18:37:32 +0000 (+0200)
Subject: libmount: don't use setgroups at all()
X-Git-Tag: v2.38-rc1~335
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c6d0ea9844fb502e79e558a4ef79ab4e4746afe6;p=thirdparty%2Futil-linux.git

libmount: don't use setgroups at all()

It's probably good idea to call setgroups() to cleanup groups,
but it introduces a regression as some mount helpers depend on
supplementary groups like "network" etc.

Fixes: https://github.com/karelzak/util-linux/issues/1398
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/include/c.h b/include/c.h
index a4504e3ba5..354b59e299 100644
--- a/include/c.h
+++ b/include/c.h
@@ -340,16 +340,10 @@ static inline size_t get_hostname_max(void)
 
 static inline int drop_permissions(void)
 {
-	gid_t newgid = getgid();
-
 	errno = 0;
 
-	/* drop supplementary groups */
-	if (geteuid() == 0 && setgroups(1, &newgid) != 0)
-		goto fail;
-
 	/* drop GID */
-	if (setgid(newgid) < 0)
+	if (setgid(getgid()) < 0)
 		goto fail;
 
 	/* drop UID */