[pkg-dhcp-devel] Bug#782434: isc-dhcp-server: DHCP server segfaults when exceeding lease limit

[Jose Miguel Sanchez Ales]

Package: isc-dhcp-server
Version: 4.3.1-6
Severity: important

Dear Maintainer,

The dhcpd server dies with segmentation fault when exceeds the lease
limit in a class. For example:

#v+
class "foo" {
   match if 1 = 1;
   lease limit 1;
}
#v-

At first time, a client obtains ip and exhausts the limit:

#v+
Apr 12 09:32:06 zipi dhcpd: DHCPREQUEST for 192.168.255.106 from 00:11:22:33:44:55 via eth1
Apr 12 09:32:06 zipi dhcpd: DHCPACK on 192.168.255.106 to 00:11:22:33:44:55 (qos2) via eth1
#v-

However if a second client makes a request, the DHCP server dies:

#v+
Apr 12 09:32:33 zipi dhcpd: DHCPREQUEST for 192.168.255.106 from 00:11:22:33:44:56 via eth1: lease 192.168.255.106 unavailable.
Apr 12 09:32:33 zipi dhcpd: DHCPNAK on 192.168.255.106 to 00:11:22:33:44:56 via eth1
Apr 12 09:32:33 zipi kernel: [  607.009131] dhcpd[9787]: segfault at 30 ip 00007f31ee2d3333 sp 00007ffc6a94f300 error 4 in dhcpd[7f31ee2bc000+b3000]
#v-

On wheezy the behavior is correct:

#v+
DHCPDISCOVER from 00:11:22:33:44:70 via eth1: no available billing: lease limit reached in all matching classes
#v-

-- System Information:
Debian Release: 8.0
  APT prefers testing-updates
  APT policy: (500, 'testing-updates'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.16.0-4-amd64 (SMP w/1 CPU core)
Locale: LANG=es_ES.UTF-8, LC_CTYPE=es_ES.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages isc-dhcp-server depends on:
ii  debconf [debconf-2.0]  1.5.56
ii  debianutils            4.4+b1
ii  isc-dhcp-common        4.3.1-6
ii  libc6                  2.19-17
ii  libdns-export100       1:9.9.5.dfsg-9
ii  libirs-export91        1:9.9.5.dfsg-9
ii  libisc-export95        1:9.9.5.dfsg-9
ii  lsb-base               4.1+Debian13+nmu1

isc-dhcp-server recommends no packages.

Versions of packages isc-dhcp-server suggests:
pn  isc-dhcp-server-ldap  <none>

-- Configuration Files:
/etc/dhcp/dhcpd.conf changed:
ddns-update-style none;                                                                                                                                 
default-lease-time 18000;                                                                                                                               
max-lease-time 18000;                                                                                                                                   
                                                                                                                                                        
class "foo" {                                                                                                                                           
   match if 1 = 1;                                                                                                                                      
   lease limit 1;                                                                                                                                       
}                                                                                                                                                       
                                                                                                                                                        
subnet 192.168.255.0 netmask 255.255.255.0 {                                                                                                            
   option domain-name-servers  192.168.255.1;                                                                                                           
   option domain-name "smr1.lan";                                                                                                                 
   option routers 192.168.255.1;                                                                                                                        
   option broadcast-address 192.168.1.255;                                                                                                              
   range 192.168.255.100 192.168.255.150;                                                                                                               
}


-- debconf information:
  isc-dhcp-server/interfaces: