Bug 616393

+++ This bug was initially created as a clone of Bug #615719 +++

Description of problem:
Mount of tmpfs where fstab contains "user" option still requires root privilege.

Version-Release number of selected component (if applicable):
util-linux-ng-2.17.2-5.fc13.i686
Problem appears present at least back to Fedora12.

How reproducible:
100%

Steps to Reproduce:
1. Add fstab entry like
tmpfs  /mnt/ramdisk tmpfs user,noauto		0 0	
2. Create mountpoint
mkdir /mnt/ramdisk
3. Attempt to mount from non-root account:
mount /mnt/ramdisk

  
Actual results:
[stevea@nidula mount]$ tail -1 /etc/fstab
tmpfs			/mnt/ramdisk		tmpfs	user,noauto,ro		0 0	
[stevea@nidula mount]$ ls -ld /mnt/ramdisk/
drwxrwxrwt 2 root root 40 Jul 18 04:03 /mnt/ramdisk/
[stevea@nidula mount]$ mount /mnt/ramdisk
mount: only root can do that
[stevea@nidula mount]$ 

Expected results:
tmpfs should mount at /mnt/ramdisk WITHOUT requiring root privilege.

Additional info:
This problem results from the correction to bug 476964
https://bugzilla.redhat.com/show_bug.cgi?id=476964
The script /sbin/mount.tmpfs is called from mount, and in turn  exec's "mount -i-t tmpfs -o user,...".   For obvious reasons the mount command cannot accept the "-o user" option from the command line.  The script solution to 476964 does not correctly preserve mount functionality.


--- Additional comment from kzak on 2010-07-20 03:30:33 EDT ---

Proposed patch:

--- mount.tmpfs	12 Apr 2010 13:19:23 -0000	1.5
+++ mount.tmpfs	20 Jul 2010 07:28:09 -0000
@@ -18,6 +18,24 @@
       ;;
 esac
 
+restricted=1
+ruid=$(id --user --real)
+euid=$(id --user)
+
+if [ $ruid -eq 0 ] && [ $ruid -eq $euid ]; then
+  restricted=0
+fi
+
+# mount(8) in restricted mode (for non-root users) does not allow to use any
+# mount options, types or so on command line. We have to call mount(8) with
+# mountpoint only.  All necessary options have to be defined in /etc/fstab.
+#
+# https://bugzilla.redhat.com/show_bug.cgi?id=615719
+#
+if [ $restricted -eq 1 ]; then
+  exec /bin/mount -i "$2"
+fi
+
 # Remount with context mount options is unsupported
 # http://bugzilla.redhat.com/show_bug.cgi?id=563267
 #