[Bug 159557] NFSv3 in Gutsy maps uids wrongly

[gcc]

Public bug reported:

Binary package hint: linux-generic

Mounting an NFS share from a FC2 server:

  /home 10.0.156.*(rw,async,no_root_squash)

10.0.156.32 (client) is edgy (2.6.17-12-generic) and appears to work.
/etc/fstab has:

  server:/home /home nfs rw,soft,intr 0 0

This machine can access NFS home dirs just fine. It appears to be using
NFSv3, from nfsstat.

10.0.156.33 (client) is gutsy (2.6.22-14-generic) and NFSv3 appears to
be broken. Cannot write to any files except in world-writable
directories, and the uid/gid is set to -2 always, like all_squash was in
effect, but this is done by the _client_.

pcap from edgy (attached):

15:53:52.761340 IP (tos 0x0, ttl 64, id 61342, offset 0, flags [DF],
proto TCP (6), length 240) 10.0.156.32.2762603457 > 10.0.156.210.nfs:
188 create fh
Unknown/01000001000900040180A6019CC2C601439E139000000004666F6F3400000000
"foo4"

pcap from gutsy (attached):

15:51:58.818008 IP (tos 0x0, ttl 64, id 63870, offset 0, flags [DF],
proto TCP (6), length 324) 10.0.156.210.nfs > 10.0.156.33.2510850134:
reply ok 272 create fh
Unknown/01000002000900040180A601A8C2C601939E13909CC2C601439E139000000001
REG 100644 ids -2/-2 sz 0

In both cases it's creating a file in a world-writable directory. Gutsy
uses the wrong permissions.

Forcing gutsy to use nfsv2 by mounting with nfsvers=2 option appears to
work around the problem.

This may be a security issue because users can create files with
uids/gids other than their own the nobody uid/gid).

I can try an alternative kernel but please post a direct HTTP link to
download it.

** Affects: linux-meta (Ubuntu)
     Importance: Undecided
         Status: New

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NFSv3 in Gutsy maps uids wrongly
https://bugs.launchpad.net/bugs/159557
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