dhclient prevents itself from accessing its own leases file

[David Riebenbauer]

I have my eth0 in /etc/network/interfaces configured to get it's information from
dhcp. This results in dhclient to be tun as root.

Ubuntu's version of dhcp3-client apparently has a patch applied that changes the
user and group to dhcp:dhcp after the lease has been obtained and the leases file
has been written. Unfortunatly dhclient will not be able to update the leases file
when the lease is refreshed, because only root has the right to do that and dhclient
has droppped it's privileges.

As a result the message:

"localhost dhclient: can't create /var/run/dhclient.eth0.leases:
+Permission denied" appears in syslog and the leases file is not rewritten

[David Riebenbauer (davrieb)]

Created an attachment (id=5200)
dpatch to fix wrong permisions of leases file

this patch chowns the leases file before dhclient drops it's privileges

[Martin Pitt (pitti)]

This has already been fixed some weeks ago in

dhcp3 (3.0.3-5ubuntu3) dapper; urgency=low

  * debian/patches/deroot-client.dpatch:
    - rewrite_client_leases(): Truncate and rewind the leases file instead of
      closing and reopening it. The latter is not possible any more with
      dropped root privileges.
    - See bug #24292 (which has a different cause, but led to discovering this
      one).

[kvdb (kc0)]

Please also apply this patch to the dhcp3-client package in breezy, in which the same issue is (still) present.

[Martin Pitt (pitti)]

Fixed package prepared, pending approval:

 dhcp3 (3.0.2-1ubuntu7) breezy-updates; urgency=low
 .
   * debian/patches/deroot-client.dpatch:
     - rewrite_client_leases(): Truncate and rewind the leases file instead of
       closing and reopening it. The latter is not possible any more with
       dropped root privileges.
     - Fix taken from Dapper version 3.0.3-5ubuntu3.
     - Malone #26645

[Matt Zimmerman (mdz)]

OK for breezy-updates

[Martin Pitt (pitti)]

Breezy-updates package was uploaded, pending upload processing now.

[Colin Watson (cjwatson)]

Accepted for breezy-updates.

[Martin Pitt (pitti)]

Package has been released. Enjoy!

[Chris Wagner (chris-wagner)]

Sorry, I accidentally hit that button that says "Yes, I want to report this bug in Ubuntu".