Bug 796992 - krb5p mounts fail against a Microsoft 8 server.
krb5p mounts fail against a Microsoft 8 server.
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: kernel (Show other bugs)
Unspecified Unspecified
unspecified Severity unspecified
: rc
: ---
Assigned To: Steve Dickson
Jian Li
Depends On:
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Reported: 2012-02-23 20:01 EST by Steve Dickson
Modified: 2014-03-03 19:08 EST (History)
6 users (show)

See Also:
Fixed In Version: kernel-2.6.32-288.el6
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2013-02-21 01:03:36 EST
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description Steve Dickson 2012-02-23 20:01:29 EST
Description of problem:

Using the -o krbp mount which ensure encrypting 
every RPC request fails against an Microsoft 8 NFS
server.The reason being the client does not rotate 
the encryption properly. The broken code is:

 * We cannot currently handle tokens with rotated data.  We need a
 * generalized routine to rotate the data in place.  It is anticipated
 * that we won't encounter rotated data in the general case.
static u32
rotate_left(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf, u16 rrc)
    unsigned int realrrc = rrc % (buf->len - offset - GSS_KRB5_TOK_HDR_LEN);

    if (realrrc == 0)
        return 0;

    dprintk("%s: cannot process token with rotated data: "
        "rrc %u, realrrc %u\n", __func__, rrc, realrrc);
    return 1;

The debug message can be seen by enable debug with
   rpcdebug -m rpc -s auth

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1.mount -o sec=krb5p,v3  microsoft:/export /mnt
Actual results:
mount.nfs: mount system call failed
Comment 4 Suzanne Yeghiayan 2012-05-18 16:54:00 EDT
This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.
Comment 5 RHEL Product and Program Management 2012-06-27 09:49:44 EDT
This request was evaluated by Red Hat Product Management for
inclusion in a Red Hat Enterprise Linux release.  Product
Management has requested further review of this request by
Red Hat Engineering, for potential inclusion in a Red Hat
Enterprise Linux release for currently deployed products.
This request is not yet committed for inclusion in a release.
Comment 6 Jarod Wilson 2012-07-23 12:09:21 EDT
Patch(es) available on kernel-2.6.32-288.el6
Comment 9 Jian Li 2013-01-25 03:36:23 EST
This bug is verified on 2.6.32-355.el6.x86_64.

[root@hp-xw4600-01 ~]# uname -a
Linux hp-xw4600-01.rhts.eng.nay.redhat.com 2.6.32-355.el6.x86_64 #1 SMP Tue Jan 15 17:45:38 EST 2013 x86_64 x86_64 x86_64 GNU/Linux
[root@hp-xw4600-01 ~]# mount ibm-x3250m4-03.rhts.eng.nay.redhat.com:/nfs /mnt/test -o vers=3,sec=krb5 -vv
mount: no type was given - I'll assume nfs because of the colon
final mount options: 'vers=3,sec=krb5'
mount.nfs: timeout set for Fri Jan 25 03:37:14 2013
mount.nfs: trying text-based options 'vers=3,sec=krb5,addr='
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying prog 100005 vers 3 prot UDP port 2049
ibm-x3250m4-03.rhts.eng.nay.redhat.com:/nfs on /mnt/test type nfs (rw,vers=3,sec=krb5)
[root@hp-xw4600-01 ~]# grep "/mnt/test" /proc/mounts 
ibm-x3250m4-03.rhts.eng.nay.redhat.com:/nfs /mnt/test nfs rw,relatime,vers=3,rsize=32768,wsize=32768,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=krb5,mountaddr=,mountvers=3,mountport=2049,mountproto=udp,local_lock=none,addr= 0 0
Comment 11 errata-xmlrpc 2013-02-21 01:03:36 EST
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


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