On Fri, Jan 31, 2025 at 02:20:04PM +0100, Mathieu ABATI wrote: > Hi, > > I am using dnsmasq through libvirt, and I get a crash when I send > SIGHUP to dnsmasq, my setup is using a configuration with hosts and > options files including tags. > No error in my configuration files is reported by dnsmasq. > I attached some files to have a simple setup to reproduce the issue. > > 1. Prepare network interfaces by running setup.sh script, it creates > bridged virtual interfaces to simulate DHCP server and client. > 2. Run dnsmasq: sudo dnsmasq -d --conf-file=dnsmasq.conf > 3. Simulate a DHCP request from the host present in hosts.conf (else > the crash will not occur): sudo dhclient -v -d dhclient-test > 4. Send SIGHUP to dnsmasq to trigger hosts and options files reload. You > get a crash with "double free or corruption (out)" message. > 5. Cleanup with cleanup.sh script. > > If you edit hosts.conf to remove the ",set:group1" part, no more crash doing > the same operations. > So it seems to be related on tags reload in hosts file. > > Reproduced on ArchLinux and Ubuntu using dnsmasq 2.90.
Please reproduce with dnsmasq 2.91test9 and after that, reproduce with the patch from Brain Haley from 2025-01-23. > As a workaround to this problem, I removed tags from hosts.conf file > and I have added such entry in the main configuration file: > dhcp-mac=set:group1,52:54:00:3b:e8:08 > This is not reloaded on SIGHUP, but this is acceptable in my use case > where I only need to update static IP addresses and options. > But indeed it doesn't allow to dynamically add new tagged hosts without > restarting dnsmasq process. > > Best regards > strict-order > except-interface=lo > bind-dynamic > leasefile-ro > interface=dnsmasq-test > dhcp-range=192.168.126.2,192.168.126.254,255.255.255.0 > dhcp-no-override > dhcp-authoritative > dhcp-lease-max=253 > dhcp-hostsfile=hosts.conf > dhcp-optsfile=options.conf > tag:group1,option:dns-server,8.8.8.8,8.8.4.4 > 52:54:00:3b:e8:08,set:group1,192.168.126.2 Groeten Geert Stappers -- Silence is hard to parse _______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss
