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

[jay at gr-oss.io]

Hi Lou,

I'd be curious if https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commitdiff;h=f006be7842104a9f86fbf419326b7aad08ade61d
could fix your issue. It corrected a similarly-presenting issue in OpenStack Ironic's updating of DHCP options recently.

It hasn't been added to any releases yet, so you will need to build it locally. We have a bash function here: 
https://github.com/openstack/ironic/blob/360e21124c2369174d7b38fbb8edf581e85f52e0/devstack/lib/ironic#L3565
which builds the newer version for our CI, you're welcome to borrow it -- although I'd suggest installing to /opt
or /usr/local unless you don't mind making your package manager angry :D. 

-
Jay Faulkner

On 11/29/24 4:22 AM, Lou Lecrivain via Dnsmasq-discuss <dnsmasq-discuss at lists.thekelleys.org.uk> wrote:
> 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 <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 <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
> 📧 lou.lecrivain at wdz.de <mailto:lou.lecrivain at wdz.de>
> <https://outlook.office.com/bookwithme/ 
> user/347bbab3d47d435cadf7ceea954b35d8 at wdz.de?anonymous&ep=signature> 		
> Book a meeting with me <https://outlook.office.com/bookwithme/ 
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