Bug 450867

+++ This bug was initially created as a clone of Bug #448787 +++

Description of problem:
Attempting to mount an ecryptfs overlay on an nfs share fails with a somewhat
cryptic message:

Error mounting eCryptfs; rc = [-95]; strerr = [Operation not supported]. Check
your system logs; visit <http://ecryptfs.sourceforge.net/ecryptfs-faq.html>.

System logs say:

SELinux: (dev ecryptfs, type ecryptfs) has no security xattr handler

The secret decoder ring says that the root of this error is ecryptfs wanting to
use extended attributes, but they aren't supported on nfs.


Version-Release number of selected component (if applicable):
kernel-2.6.18-92.el5
ecryptfs-utils-41-1.el5
selinux-policy-2.4.6-137.el5

How reproducible:
Mount nfs share, create directory on share, try to do an ecryptfs overlay mount
on top of it.

Additional info:
Passing these extra options: -o context=system_u:object_r:user_home_t:s0 on the
ecryptfs mount command line works around the problem.

-- Additional comment from jwilson on 2008-06-03 15:23 EST --
More complete instructions for reproducer setup:

1) export /data on server
2) mount server:/data to /data on client
3) create directory /data/encrypted
4) # mount -t ecryptfs /data/encrypted /data/encrypted
   Select key type to use for newly created files: 
    1) openssl
    2) passphrase
   Selection: 2
   Passphrase: foofoo
   Verify Passphrase: foofoo 
   Select cipher: 
    1) aes: blocksize = 16; min keysize = 16; max keysize = 32 (loaded)
    2) blowfish: blocksize = 16; min keysize = 16; max keysize = 32 (not loaded)
    3) des3_ede: blocksize = 8; min keysize = 24; max keysize = 24 (not loaded)
    4) twofish: blocksize = 16; min keysize = 16; max keysize = 32 (not loaded)
    5) cast6: blocksize = 16; min keysize = 16; max keysize = 32 (not loaded)
    6) cast5: blocksize = 8; min keysize = 5; max keysize = 16 (not loaded)
   Selection [aes]: aes
   Select key bytes: 
    1) 16
    2) 32
    3) 24
   Selection [16]: 2
   Attempting to mount with the following options:
     ecryptfs_key_bytes=32
     ecryptfs_cipher=aes
     ecryptfs_sig=92868a6a72b0202e
   Error mounting eCryptfs; rc = [-95]; strerr = [Operation not supported].
   Check your system logs; visit
<http://ecryptfs.sourceforge.net/ecryptfs-faq.html>.


-- Additional comment from esandeen on 2008-06-03 16:57 EST --
FWIW, this behavior changed between selinux-policy-2.4.6-104.el5 and
selinux-policy-2.4.6-137.el5, if that's relevant ...

the older version let us mount ok.

-- Additional comment from dwalsh on 2008-06-04 13:52 EST --
Are you getting any messages in /var/log/audit/audit.log?

-- Additional comment from eparis on 2008-06-04 14:01 EST --
dan, I assume this was the addition of an fs_use rule for ecryptfs  I've got a
patch I hoped to get to list today which should allow us to drop ecryptfs
definition from policy and things will 'just work'

But its as of yet untested

-- Additional comment from pm-rhel on 2008-06-11 10:25 EST --
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.