From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id DFC851FF178 for ; Mon, 1 Dec 2025 10:16:30 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id BB8B916705; Mon, 1 Dec 2025 10:16:52 +0100 (CET) Message-ID: <8eb64198-9761-4a0a-ab26-06c8d1774681@proxmox.com> Date: Mon, 1 Dec 2025 10:16:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: pve-devel@lists.proxmox.com References: <20251126154928.430607-1-s.hanreich@proxmox.com> Content-Language: en-US From: Stefan Hanreich In-Reply-To: <20251126154928.430607-1-s.hanreich@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL -0.275 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment KAM_MAILER 2 Automated Mailer Tag Left in Email RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_RPBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_SAFE_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] [PATCH pve-network 1/1] fix #5949: avoid dnsmasq segfault when subnet has no gateway X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox VE development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" 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 > --- > 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 pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel