A flaw was reported in ISC DHCP  where it was found that reducing the expiration time for an active IPv6 lease could possible cause the dhcpd server to crash, resulting in a denial of service condition for clients.
ISC has recommended that when setting a value for the default-least-time option, that it be done in the configuration file and not reduced once set.
This has been corrected in upstream versions 4.1-ESV-R7 and 4.2.4-P2.
Created attachment 612210 [details]
fix derived from upstream dhcp-4.2.4-P2
Created dhcp tracking bugs for this issue
Affects: fedora-all [bug 856770]
Created attachment 613622 [details]
patch for dhcp-4.1.1-P1 in RHEL-6
extracted from diff of dhcp-4.1-ESV-R6 and dhcp-4.1-ESV-R7
dhcp-4.2.4-15.P2.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.
Upstream recommends that this issue can be mitigated by setting a value for the "default-lease-time" option in the configuration file and should not reduced once it is set.
This issue does not affect the version of dhcp as shipped with Red Hat Enterprise Linux 5.
dhcp-4.2.4-13.P2.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.
dhcp-4.2.4-1.P2.fc16 has been pushed to the Fedora 16 stable repository. If problems still persist, please make note of it in this bug report.
This issue has been addressed in following products:
Red Hat Enterprise Linux 6
Via RHSA-2013:0504 https://rhn.redhat.com/errata/RHSA-2013-0504.html