the mentioned fix has been upstreamed: https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=eb601683820723df89858cfa695aa131012f1a63
On 11/26/25 4:48 PM, Stefan Hanreich wrote: > When trying to start a guest with a network device in a VNet in a > simple zone that has DHCP enabled - but no gateway configured - a > SIGSEGV is triggered in dnsmasq. This seems to be an error in the > dnsmasq dbus handler that tries to allocate a lease, which fails > because there is no dhcp-range configured, and then leads to a > segfault. > > Avoid the situation completely by always configuring a dhcp-range, > even if there is no gateway configured. Skip configuring the DHCP > option that returns the router instead, which is the only place in the > configure_subnet function that uses the gateway. > > Dnsmasq is configured to listen on an interface, so any DHCP messages > that are received on this interface are dropped, because dnsmasq > recognizes that there is no IP configured on this interface: > > Nov 26 16:35:49 ipam-test dnsmasq-dhcp[140272]: DHCP packet received on vnet1 > which has no address > Nov 26 16:35:57 ipam-test dnsmasq-dhcp[140272]: DHCP packet received on vnet1 > which has no address > > An initial upstream patch to fix the segfault has been submitted here > [1]. > > [1] > https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2025q4/018342.html > > Signed-off-by: Stefan Hanreich <[email protected]> > --- > src/PVE/Network/SDN/Dhcp/Dnsmasq.pm | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > b/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > index db22e12..6a1e3b0 100644 > --- a/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > +++ b/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > @@ -138,9 +138,6 @@ sub add_ip_mapping { > sub configure_subnet { > my ($class, $config, $dhcpid, $vnetid, $subnet_config) = @_; > > - die "No gateway defined for subnet $subnet_config->{id}" > - if !$subnet_config->{gateway}; > - > my $tag = $subnet_config->{id}; > > my ($zone, $network, $mask) = split(/-/, $tag); > @@ -155,7 +152,7 @@ sub configure_subnet { > my $option_string; > if (ip_is_ipv6($subnet_config->{network})) { > $option_string = 'option6'; > - } else { > + } elsif ($subnet_config->{gateway}) { > $option_string = 'option'; > push @{$config}, > "dhcp-option=tag:$tag,$option_string:router,$subnet_config->{gateway}"; > } _______________________________________________ pve-devel mailing list [email protected] https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
