[Dnsmasq-discuss] BUG Segfault when adding ethers entry via dBus and no dhcp-range is configured - debian version 2.89-1

[Lou.Lecrivain at wdz.de]

Hello,

I'd like to make a bug report following an issue discovered via Proxmox VE #5949 (https://bugzilla.proxmox.com/show_bug.cgi?id=5949). This happens on debian dnsmasq package version 2.89-1. I have not yet tested on latest release / dev, but if you wish, I can try to reproduce on it too.

How to reproduce:

  *
general dnsmasq configuration
  *
configure interface (not sure this is mandatory for reproduction)
  *
configure dhcp-option for a subnet (same comment)
  *
do NOT create the dhcp-range in the config file
  *
write ethers file with an entry that's in the subnet without dhcp-range
  *
ask for reload via systemd
  *
update lease via dBus, see code with link below
https://git.proxmox.com/?p=pve-network.git;a=blob;f=src/PVE/Network/SDN/Dhcp/Dnsmasq.pm;h=ae52d3199e0fc51fd1401d7dd78085ad730e5588;hb=refs/heads/master#l41
  *
segfault happens at this point

Restarting manually via systemctl after the crash does not yields any further errors.

The crash/segmentation fault precisely happens just right after reload is triggered. I have the following message in journalctl (sorry for the french!):
nov. 28 12:49:38 debian12-dev systemd[1]: Starting dnsmasq at simple.service - dnsmasq (simple) - A lightweight DHCP and caching DNS server>
nov. 28 12:49:38 debian12-dev dnsmasq[10598]: demarré, version 2.89 (taille de cache 150)
nov. 28 12:49:38 debian12-dev dnsmasq[10598]: options à la compilation : IPv6 GNU-getopt DBus no-UBus i18n IDN2 DHCP DHCPv6 no-Lua TFTP >
nov. 28 12:49:38 debian12-dev dnsmasq[10598]: Support DBus autorisé : connecté au bus système
nov. 28 12:49:38 debian12-dev dnsmasq-dhcp[10598]: annonces de routeur IPv6 activées
nov. 28 12:49:38 debian12-dev dnsmasq[10598]: Lecture de /etc/resolv.conf
nov. 28 12:49:38 debian12-dev dnsmasq[10598]: utilise le serveur de nom 192.168.122.1#53
nov. 28 12:49:38 debian12-dev dnsmasq[10598]: cache vidé
nov. 28 12:49:39 debian12-dev systemd[1]: Started dnsmasq at simple.service - dnsmasq (simple) - A lightweight DHCP and caching DNS server.
nov. 28 12:49:44 debian12-dev systemd[1]: dnsmasq at simple.service: Main process exited, code=killed, status=11/SEGV

Don't hesitate to get back to me if you need further details.

Best regards
--
Lou Lécrivain
Systems & Network engineer
WDZ GmbH[cid:84f4bb77-1e41-46c1-a65e-6bb33f657272]
📧 lou.lecrivain at wdz.de<mailto:lou.lecrivain at wdz.de>
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