What were you trying to do that didn't work?

[rhel10.0]dnsmasq block virbr0 loading when re-modprobe bridge

Please provide the package NVR for which bug is seen:

[root@dell-per740-15 ~]# uname -r
6.10.0-15.el10.x86_64

How reproducible: 100%

Steps to reproduce

1. 
[root@dell-per740-15 ~]# uname -r
6.10.0-15.el10.x86_64
 
[root@dell-per740-15 ~]# rpm -qa | grep libvirt
libvirt-libs-10.5.0-1.el10.x86_64
libvirt-client-10.5.0-1.el10.x86_64
libvirt-daemon-common-10.5.0-1.el10.x86_64
libvirt-daemon-driver-nwfilter-10.5.0-1.el10.x86_64
libvirt-daemon-lock-10.5.0-1.el10.x86_64
libvirt-daemon-log-10.5.0-1.el10.x86_64
libvirt-daemon-plugin-lockd-10.5.0-1.el10.x86_64
libvirt-daemon-config-nwfilter-10.5.0-1.el10.x86_64
libvirt-daemon-driver-interface-10.5.0-1.el10.x86_64
libvirt-daemon-driver-secret-10.5.0-1.el10.x86_64
libvirt-daemon-proxy-10.5.0-1.el10.x86_64
libvirt-daemon-10.5.0-1.el10.x86_64
python3-libvirt-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-core-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-disk-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-iscsi-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-logical-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-mpath-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-rbd-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-scsi-10.5.0-1.el10.x86_64
libvirt-daemon-driver-storage-10.5.0-1.el10.x86_64
libvirt-client-qemu-10.5.0-1.el10.x86_64
libvirt-daemon-driver-nodedev-10.5.0-1.el10.x86_64
libvirt-daemon-driver-qemu-10.5.0-1.el10.x86_64
libvirt-daemon-driver-network-10.5.0-1.el10.x86_64
libvirt-daemon-config-network-10.5.0-1.el10.x86_64
libvirt-10.5.0-1.el10.x86_64
 
[root@dell-per740-15 ~]# rpm -qa | grep qemu
qemu-img-9.0.0-4.el10.x86_64
libvirt-client-qemu-10.5.0-1.el10.x86_64
libvirt-daemon-driver-qemu-10.5.0-1.el10.x86_64
qemu-pr-helper-9.0.0-4.el10.x86_64
qemu-kvm-tools-9.0.0-4.el10.x86_64
qemu-kvm-docs-9.0.0-4.el10.x86_64
ipxe-roms-qemu-20240119-2.gitde8a0821.el10.noarch
qemu-kvm-common-9.0.0-4.el10.x86_64
qemu-kvm-device-display-virtio-gpu-9.0.0-4.el10.x86_64
qemu-kvm-ui-opengl-9.0.0-4.el10.x86_64
qemu-kvm-ui-egl-headless-9.0.0-4.el10.x86_64
qemu-kvm-device-display-virtio-gpu-pci-9.0.0-4.el10.x86_64
qemu-kvm-audio-pa-9.0.0-4.el10.x86_64
qemu-kvm-block-blkio-9.0.0-4.el10.x86_64
qemu-kvm-block-rbd-9.0.0-4.el10.x86_64
qemu-kvm-device-display-virtio-vga-9.0.0-4.el10.x86_64
qemu-kvm-device-usb-host-9.0.0-4.el10.x86_64
qemu-kvm-device-usb-redirect-9.0.0-4.el10.x86_64
qemu-kvm-core-9.0.0-4.el10.x86_64
qemu-kvm-9.0.0-4.el10.x86_64
[root@dell-per740-15 ~]# 
 
 
2.
systemctl enable --now libvirtd
systemctl status libvirtd --no-pager -l
 
3.check:
[root@dell-per740-15 ~]# ip link show  virbr0
 
12: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
    link/ether 52:54:00:2f:5d:06 brd ff:ff:ff:ff:ff:ff
 
 
4.modprobe -r bridge, then "modprobe -v brdige"
 
5.check interface virbr0
[root@dell-per740-15 ~]# ip link show virbr0
Device "virbr0" does not exist.
 
6. virsh net-list --all
virsh net-destroy default
virsh net-autostart default
virsh net-start default
 
[root@dell-per740-15 ~]# ip link show virbr0
Device "virbr0" does not exist.
[root@dell-per740-15 ~]# virsh net-list --all
 Name      State      Autostart   Persistent
----------------------------------------------
 default   inactive   yes         yes
 
[root@dell-per740-15 ~]# virsh net-destroy default
error: Failed to destroy network default
error: Requested operation is not valid: network 'default' is not active
 
[root@dell-per740-15 ~]# virsh net-autostart default
Network default marked as autostarted
 
[root@dell-per740-15 ~]# virsh net-start default
error: Failed to start network default
error: internal error: Child process (VIR_BRIDGE_NAME=virbr0 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper) unexpected exit status 2: 
dnsmasq: failed to create listening socket for 192.168.122.1: Address already in use
 
 
[root@dell-per740-15 ~]# virsh net-list --all
 Name      State      Autostart   Persistent
----------------------------------------------
 default   inactive   yes         yes
 
 
7. if I kill dnsmasq, the do the followings, virbr0 can be loaded.
[root@dell-per740-15 ~]# ps -ef | grep dnsmasq
dnsmasq     9005       1  0 01:45 ?        00:00:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
root        9006    9005  0 01:45 ?        00:00:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
root        9967    7694  0 02:08 pts/0    00:00:00 grep --color=auto dnsmasq
[root@dell-per740-15 ~]# 
[root@dell-per740-15 ~]# pkill dnsmasq
[root@dell-per740-15 ~]# ps -ef | grep dnsmasq
root        9978    7694  0 02:09 pts/0    00:00:00 grep --color=auto dnsmas
 
[root@dell-per740-15 ~]# virsh net-start default
Network default started
 
[root@dell-per740-15 ~]# ip link show virbr0
16: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
    link/ether 52:54:00:2f:5d:06 brd ff:ff:ff:ff:ff:ff
 

Expected results

In step6, after the commands execution, virbr0 can not be seen via "ip link show"

Actual results

In step6, after the command execution, virbr0 can not be seen with "ip link show"