From: Karel Zak <kzak@redhat.com>
Date: Wed, 30 Sep 2009 14:54:17 +0000 (+0200)
Subject: mount: more verbose "mount: only root can do that" message
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3d1b35b62dd15282162c21895c25b297768dcbb6;p=util-linux

mount: more verbose "mount: only root can do that" message

> [chroot-i486] root:/$ whoami
> root
> [chroot-i486] root:/$ mkdir -p /dev1
> [chroot-i486] root:/$ mount --move /dev /dev1
> mount: only root can do that

Reported-by: Gilles Espinasse <g.esp@free.fr>
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/mount/mount.c b/mount/mount.c
index e8cb5499..23d70cb1 100644
--- a/mount/mount.c
+++ b/mount/mount.c
@@ -2205,12 +2205,18 @@ main(int argc, char *argv[]) {
 		if (((uid_t)0 == ruid) && (ruid == euid)) {
 			restricted = 0;
 		}
-	}
 
-	if (restricted &&
-	    (types || options || readwrite || nomtab || mount_all ||
-	     fake || mounttype || (argc + specseen) != 1)) {
-		die (EX_USAGE, _("mount: only root can do that"));
+		if (restricted &&
+		    (types || options || readwrite || nomtab || mount_all ||
+		     fake || mounttype || (argc + specseen) != 1)) {
+
+			if (ruid == 0 && euid != 0)
+				/* user is root, but setuid to non-root */
+				die (EX_USAGE, _("mount: only root can do that "
+					"(effective UID is %d)"), euid);
+
+			die (EX_USAGE, _("mount: only root can do that"));
+		}
 	}
 
 	atexit(unlock_mtab);