RHBA-2004:566 - Bug Fix Advisory

Topic

Updated DHCP and dhclient packages that fix various bugs and add various
enhancements are now available.

Description

DHCP (Dynamic Host Configuration Protocol) is a protocol which allows
individual devices on an IP network to get their own network
configuration information (IP address, subnetmask, broadcast address,
etc.) from a DHCP server. The overall purpose of DHCP is to make it
easier to administer a large network. The dhcp package includes the
ISC DHCP service and relay agent.

To use DHCP on your network, install a DHCP service (or relay agent),
and on clients run a DHCP client daemon. The dhcp package provides
the ISC DHCP service and relay agent.

The following bugs and enhancements have been addressed in these updated
packages:

• The 'client_ddns_update' function was never reached in DHCP code

versions 3.0.1-14 - 3.0.1-final

• The host-specific options could be inherited from previous hosts

due to a pointer not being freed correctly

• The fix for host-specific option processing incorrectly disabled some

host-specific options

• Fixed a lost dhcp leases file
• The DHCP server would not start if the /var/lib/dhcpd.leases file did

not exist

• NTP drift file set to wrong location when obtaining a lease
• The dhclient presets had a bad drift file location
• Incorrect path for drift file is generated in /etc/ntp.conf
• The ntp drift file had an incorrect path
• The /etc/ntp/data directory did not exist
• The dhclient-script created incorrect /etc/ntp.conf file
• The dhclient-script contained the wrong location for the NTP drift file
• The /sbin/dhclient-script did not like 'netprofiles'
• The dhclient application did not work with custom-named network devices

The dhclient script now operates correctly with system-config-network
"profiles" and alias ethernet devices

• After running latest 'yum update' DNS stopped resolving
• Use of the 'prepend'/'append'/'supersede' dhcp-options is now fully

supported in the /etc/dhclient.conf or /etc/dhclient-$IF.conf files

• /sbin/dhclient-script no longer uses /usr/bin/expr
• No new address obtained after network restart. Now dhclient gets a new

lease

• Several operating system specific builds had a C include that overrides

the vsnprintf function to vsprintf. The vsnprintf is now used.

• Feature to reuse unexpired leases has been added
• A dhcp-options(5) man-page now included
• The dhclient-script command now operates correctly with no default route
• The 'PERSISTENT-DHCLIENT' option was added to

/etc/sysconfig/network-scripts/ifcfg-$IF files. If specified, dhclient
is no longer invoked in 'one-shot' (-1) mode, but keeps trying to
contact DHCP servers.

• Updated the IP_V_SET macro
• The dhclient command now handles new static routes sent by the server
• The dhclient command no longer overwrites ntp.conf
• dhcpd and dhclient now check for correct config file syntax before

restarting

• The dhclient command now replaces the dhcpcd daemon
• The dhclient command now ignores IPV6-only interfaces
• A configtest option has been added to /etc/init.d/dhcpd
• The dhclient command now updates resolv.conf correctly
• The dhcrelay script now operates correctly
• Active interfaces are no longer shut down by dhclient

Users of dhcpd and dhclient should upgrade to these updated packages, which
resolve these issues.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied. Use Red Hat
Network to download and update your packages. To launch the Red Hat
Update Agent, use the following command:

up2date

For information on how to install packages manually, refer to the
following Web page for the System Administration or Customization
guide specific to your system:

http://www.redhat.com/docs/manuals/enterprise/

Affected Products

• Red Hat Enterprise Linux Server 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 100555 - RFE: Fix handling of already active interfaces
• BZ - 100765 - init.d/dhcrelay fails silently ignoring DHCPSERVERS in sysconfig/dhcrelay
• BZ - 100817 - dhclient-script generates /etc/ntp.conf crippling NTP
• BZ - 102394 - [dhclient] resolv.conf issue
• BZ - 102738 - dhcp init script should have a "configtest" option similar to apache's
• BZ - 103284 - dhcpd not updating dhcpd.leases
• BZ - 103628 - dhclient crashes with floating point exception when DHCP server returns zero leasetime
• BZ - 104511 - dhcpd brings down interface when it has IPv6 but not IPv4 address.
• BZ - 105893 - /etc/ntp/data directory does not exist
• BZ - 106275 - dhclient-script ignores prepend, append statements
• BZ - 108426 - ntp drift file has incorrect path
• BZ - 110250 - no refresh of resolv.conf via dhcp
• BZ - 111130 - dhcpcd frequently fails stating no link present
• BZ - 111213 - dhclient should obsolete dhcpcd
• BZ - 111540 - dhcpcd not present in RHEL3, was present in previous release (RH7.2)
• BZ - 111860 - Check for correct syntax before restart
• BZ - 112273 - dhclient overwrites ntp.conf
• BZ - 113190 - dhclient-script doesn't handle new_static_routes
• BZ - 113665 - broken data field read ?
• BZ - 114173 - dhclient couldn't get online with t-mobile hotspot at SFO
• BZ - 114177 - dhclient doesn't get lease from nt4 dhcp, pump does
• BZ - 117147 - DHCP creates malformed packets which DOS netgear ADSL router
• BZ - 117779 - Dhclient presets bad driftfile location
• BZ - 118461 - /etc/rc.d/init.d/dhcpd: Missing dhcpd.leases causes the script to exit silently
• BZ - 120093 - dhclient dies if it doesn't get an answer from the dhcp server
• BZ - 120428 - [PATCH] dhclient -s IP fails(hangs) if no default route
• BZ - 123217 - dhcp 3.0.1 rc13 is available
• BZ - 124022 - dhclient does not work with custom-named network devices
• BZ - 124834 - dhcp package does not include dhcp-options file
• BZ - 125298 - need way to carry over old lease to dhclient
• BZ - 125926 - CAN-2004-0460/1 DHCP stack overflow in hostname logging
• BZ - 126058 - Host unreachable after network restart
• BZ - 126255 - /sbin/dhclient-script must not use '/usr/bin/expr'
• BZ - 126541 - dhcp 3.0.1rc14 is available
• BZ - 126551 - dhclient generates wrong lease records
• BZ - 126637 - DHCP lease renewals overwrite /etc/resolv.conf thereby throwing away nameservers needed by VPN
• BZ - 127232 - DHCPD creates duplicate ARP entries on multiple interfaces.
• BZ - 127272 - Ethernet aliases no longer work for orinoco_cs adapter
• BZ - 128655 - RFE (patch included): Update ISC named config based on DHCP info.
• BZ - 129358 - Update dhcpd to 3.0.1 for RHEL3 UPD3
• BZ - 129417 - dhclient should probably send option 61 by default
• BZ - 129646 - dhclient not updating DNS FQDN correctly
• BZ - 130069 - Client forward DNS update disabled by bug in dhclient
• BZ - 130684 - dhcp erasing resolv.conf
• BZ - 130699 - dhclient nukes /etc/resolv.conf
• BZ - 130848 - After running latest 'yum update' dns stops resolving
• BZ - 131212 - "booting disallowed" for hosts that should get addresses
• BZ - 131733 - Incorrect path for drift file is generated in /etc/ntp.conf
• BZ - 132361 - /sbin/dhclient-script does not like 'netprofiles'
• BZ - 133038 - NTP driftfile set to wrong location when obtaing lease
• BZ - 133192 - lost dhcp leases file
• BZ - 133522 - Cannot netboot hosts with dhcp 3.0.1-8

CVEs

(none)

References

• Latest Package Version:
• dhcp-3.0.1-10_EL3
• dhclient-3.0.1-10_EL3