#828972 isc-dhcp-server: segmentation fault in ddns.c during ipv6 DDNS updates

Package:
isc-dhcp-server
Source:
isc-dhcp
Description:
ISC DHCP server for automatic IP address assignment
Submitter:
Alessandro Nozzoli
Date:
2026-08-05 17:34:04 UTC
Severity:
important
Tags:
#828972#5
Date:
2016-06-29 13:22:19 UTC
From:
To:
Dear Maintainer,


After a random time depending on the amount of DDNS updates requested, a
SEGV signo is
issued, causing the daemon to exit.

The core analysis reports:

Core was generated by `/usr/sbin/dhcpd -f -d -6 -cf
/etc/dhcp/dhcpd6.conf -pf /var/run/dhcpd6.pid eth3'.
Program terminated with signal SIGSEGV, Segmentation fault.

(gdb) backtrace
#0  data_string_forget (data=data@entry=0x30,
file=file@entry=0x7fcc65ece222 "ddns.c", line=line@entry=1780) at
alloc.c:1281
#1  0x00007fcc65e942a2 in ddns_cb_free (ddns_cb=0x30,
file=file@entry=0x7fcc65ece222 "ddns.c", line=line@entry=1780) at
dns.c:584
#2  0x00007fcc65e78ed9 in ddns_removals (lease=lease@entry=0x0,
lease6=lease6@entry=0x7fcc663dbd90, add_ddns_cb=add_ddns_cb@entry=0x0,
     active=active@entry=isc_boolean_false) at ddns.c:1780
#3  0x00007fcc65e875c7 in move_lease_to_inactive
(pool=pool@entry=0x7fcc66202690, lease=lease@entry=0x7fcc663dbd90,
state=state@entry=3 '\003')
     at mdb6.c:1499
#4  0x00007fcc65e88f50 in expire_lease6 (leasep=0x7ffedfa76928,
pool=0x7fcc66202690, now=1467201107) at mdb6.c:1550
#5  0x00007fcc65e8983f in lease_timeout_support (vpool=0x7fcc66202690)
at mdb6.c:1916
#6  0x00007fcc65e9320d in isclib_timer_callback (taskp=<optimized out>,
eventp=0x7fcc66055070) at dispatch.c:174
#7  0x00007fcc654becba in isc.taskmgr_dispatch () from
/lib/x86_64-linux-gnu/libisc-export.so.95
#8  0x00007fcc654c2136 in ?? () from
/lib/x86_64-linux-gnu/libisc-export.so.95
#9  0x00007fcc654c2c83 in ?? () from
/lib/x86_64-linux-gnu/libisc-export.so.95
#10 0x00007fcc65e93351 in dispatch () at dispatch.c:114
#11 0x00007fcc65e48a1b in main (argc=<optimized out>, argv=<optimized
out>) at dhcpd.c:804


The last lines in logfile are:

Added reverse map from
3.6.2.e.1.0.0.0.0.0.0.0.0.0.0.0.5.0.0.1.5.0.c.2.0.6.7.0.1.0.0.2.ip6.arpa.
to Marco-PC.lesc-ipv6
ddns.c(1278): Lease 2001:760:2c05:1005::1:e263 not found within pool.
Added reverse map from
3.6.2.e.1.0.0.0.0.0.0.0.0.0.0.0.5.0.0.1.5.0.c.2.0.6.7.0.1.0.0.2.ip6.arpa.
to Marco-PC.lesc-ipv6
ddns.c(1278): Lease 2001:760:2c05:1005::1:e263 not found within pool.
Renew message from fe80::4c7f:ea08:2dfd:fd6b port 546, transaction ID
0x14ED6700
Reply NA: address 2001:760:2c05:1005::1:b609 to client with duid
00:01:00:01:1b:30:89:53:e0:3f:49:86:cd:8f iaid = 518012745 valid for
1800 seconds
ddns.c(1552): Failed to update internal lease structure with DDNS
control block. Existing ddns_cb structure does not match
expectations.IPv6=2001:760:2c05:1005::1:b609, old
ddns_cb=0x7fcc66594320, triedto update to new ddns_cb=0x7fcc66594320
Sending Reply to fe80::4c7f:ea08:2dfd:fd6b port 546
Added new forward map from biancone.lesc-ipv6 to
2001:760:2c05:1005::1:b609
Added reverse map from
9.0.6.b.1.0.0.0.0.0.0.0.0.0.0.0.5.0.0.1.5.0.c.2.0.6.7.0.1.0.0.2.ip6.arpa.
to biancone.lesc-ipv6
ddns.c(1278): Lease 2001:760:2c05:1005::1:b609 not found within pool.
Renew message from fe80::215:99ff:fe4b:1d8a port 546, transaction ID
0xB83DD500
Discarding Renew from fe80::215:99ff:fe4b:1d8a; not our server
identifier (CLIENTID 00:03:00:01:00:15:99:4b:1d:8a, SERVERID
00:01:00:01:1d:6f:00:8c:00:50:56:00:00:03, server DUID
00:01:00:01:1f:06:43:6b:00:50:56:00:00:03)
Renew message from fe80::215:99ff:fe4b:1d8a port 546, transaction ID
0xB83DD500
Discarding Renew from fe80::215:99ff:fe4b:1d8a; not our server
identifier (CLIENTID 00:03:00:01:00:15:99:4b:1d:8a, SERVERID
00:01:00:01:1d:6f:00:8c:00:50:56:00:00:03, server DUID
00:01:00:01:1f:06:43:6b:00:50:56:00:00:03)
Errore di segmentazione (core dump creato)

#828972#10
Date:
2026-08-05 17:31:09 UTC
From:
To:
Dear submitter,

as the package isc-dhcp has just been removed from the Debian archive
unstable we hereby close the associated bug reports.  We are sorry
that we couldn't deal with your issue properly.

For details on the removal, please see https://bugs.debian.org/1143544

The version of this package that was in Debian prior to this removal
can still be found using https://snapshot.debian.org/.

Please note that the changes have been done on the master archive and
will not propagate to any mirrors until the next dinstall run at the
earliest.

This message was generated automatically; if you believe that there is
a problem with it please contact the archive administrators by mailing
ftpmaster@ftp-master.debian.org.

Debian distribution maintenance software
pp.
Thorsten Alteholz (the ftpmaster behind the curtain)