Comment 15 for bug 1943481

Installed, rebooted and VM's started up.. Fix is working

apt-cache policy libvirt-daemon-system

libvirt-daemon-system:
  Installed: 6.0.0-0ubuntu8.14
  Candidate: 6.0.0-0ubuntu8.14
  Version table:
 *** 6.0.0-0ubuntu8.14 500
        500 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64
Packages
        100 /var/lib/dpkg/status
     6.0.0-0ubuntu8.13+lp1943481v20210914b2 500
        500 http://ppa.launchpad.net/mruffell/lp1943481-test/ubuntu
focal/main amd64 Packages
     6.0.0-0ubuntu8.13 500
        500 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64
Packages
     6.0.0-0ubuntu8.3 500
        500 http://us.archive.ubuntu.com/ubuntu focal-security/main amd64
Packages
     6.0.0-0ubuntu8 500
        500 http://us.archive.ubuntu.com/ubuntu focal/main amd64 Packages

On Mon, Sep 13, 2021 at 11:55 PM Matthew Ruffell <email address hidden>
wrote:

> Hi Paul,
>
> Could you please install the libvirt packages in -proposed and verify
> that it fixes the problem?
>
> Instructions to Install (on a Focal system):
> 1) cat << EOF | sudo tee /etc/apt/sources.list.d/ubuntu-$(lsb_release
> -cs)-proposed.list
> # Enable Ubuntu proposed archive
> deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -cs)-proposed main
> universe
> EOF
> 2) sudo apt update
> 3) sudo apt install libvirt-daemon-system libvirt-clients
> 4) sudo reboot
> 5) sudo apt-cache policy libvirt-daemon-system
> Installed: 6.0.0-0ubuntu8.14
>
> You may also wish to remove the -proposed archive once you have libvirt
> installed, if this is a production machine.
> 6) sudo rm /etc/apt/sources.list.d/ubuntu-$(lsb_release -cs)-proposed.list
>
> If the fixed package works as expected, we will mark the launchpad bug
> as verified and fast-track the release to -updates.
>
> Thanks,
> Matthew
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1943481
>
> Title:
> libvirtd crashes when creating network interface pools in
> 6.0.0-0ubuntu8.13
>
> Status in libvirt package in Ubuntu:
> Invalid
> Status in libvirt source package in Focal:
> Fix Committed
>
> Bug description:
> [Impact]
>
> A regression was introduced in libvirt 6.0.0-0ubuntu8.13 for Focal,
> that affects users who use SR-IOV to pass through VF devices to KVM
> guests.
>
> The problem was introduced in the recent lp-1892132-Add-
> phys_port_name-support-on-virPCIGetNetName.patch patch, which changes
> how virPCIGetNetName() fetches the name of the underlying VF device,
> so it can be used to send netlink commands.
>
> There is a fallback case where we record the name of the device at the
> beginning, and if we fail all other lookups, we simply return the
> beginning name.
>
> In libvirt 6.0.0-0ubuntu8.13, a line to drop the reference to
> firstEntryName was dropped incorrectly:
>
> - if (firstEntryName) {
> - *netname = firstEntryName;
> - firstEntryName = NULL;
> - ret = 0;
> + if (firstEntryName) {
> + *netname = firstEntryName;
> + ret = 0;
>
> This results in a double free, as netname and firstEntryName are
> freed, and results in the gdb trace:
>
> #1 0x00007f40e5d1c859 in __GI_abort () at abort.c:79
> #2 0x00007f40e5d873ee in __libc_message (action=action@entry=do_abort,
> fmt=fmt@entry=0x7f40e5eb1285 "%s\n") at ../sysdeps/posix/libc_fatal.c:155
> #3 0x00007f40e5d8f47c in malloc_printerr (str=str@entry=0x7f40e5eb35d0
> "free(): double free detected in tcache 2") at malloc.c:5347
> #4 0x00007f40e5d910ed in _int_free (av=0x7f40c8000020, p=0x7f40c80079e0,
> have_lock=0) at malloc.c:4201
> #5 0x00007f40e61a9a4f in virFree (ptrptr=0x7f40c8003b60) at
> ../../../src/util/viralloc.c:348
> #6 0x00007f40dd0cf8b1 in networkCreateInterfacePool
> (netdef=0x7f40840187f0) at ../../../src/network/bridge_driver.c:2849
> #7 0x00007f40dd0d799c in networkStartNetworkExternal
> (obj=0x7f408400f720) at ../../../src/network/bridge_driver.c:2938
> #8 networkStartNetwork (driver=driver@entry=0x7f408400a7a0,
> obj=0x7f408400f720) at ../../../src/network/bridge_driver.c:2938
> #9 0x00007f40dd0d854d in networkCreate (net=0x7f40c8000c60) at
> ../../../src/network/bridge_driver.c:4013
> #10 0x00007f40e63fac3f in virNetworkCreate (network=network@entry=0x7f40c8000c60)
> at ../../../src/libvirt-network.c:585
> #11 0x0000560240e255d1 in remoteDispatchNetworkCreate
> (server=0x560240ea4280, msg=0x560240ee8200, args=0x7f40c8000c40,
> rerr=0x7f40e00ec9a0, client=<optimized out>) at
> ./remote/remote_daemon_dispatch_stubs.h:13570
> #12 remoteDispatchNetworkCreateHelper (server=0x560240ea4280,
> client=<optimized out>, msg=0x560240ee8200, rerr=0x7f40e00ec9a0,
> args=0x7f40c8000c40, ret=0x0) at
> ./remote/remote_daemon_dispatch_stubs.h:13549
> #13 0x00007f40e630c970 in virNetServerProgramDispatchCall
> (msg=0x560240ee8200, client=0x560240eea270, server=0x560240ea4280,
> prog=0x560240ee1520) at ../../../src/rpc/virnetserverprogram.c:430
> #14 virNetServerProgramDispatch (prog=0x560240ee1520, server=server@entry=0x560240ea4280,
> client=0x560240eea270, msg=0x560240ee8200) at
> ../../../src/rpc/virnetserverprogram.c:302
> #15 0x00007f40e6311c2c in virNetServerProcessMsg (msg=<optimized out>,
> prog=<optimized out>, client=<optimized out>, srv=0x560240ea4280) at
> ../../../src/rpc/virnetserver.c:136
> #16 virNetServerHandleJob (jobOpaque=<optimized out>,
> opaque=0x560240ea4280) at ../../../src/rpc/virnetserver.c:153
> #17 0x00007f40e62301af in virThreadPoolWorker (opaque=opaque@entry=0x560240e885f0)
> at ../../../src/util/virthreadpool.c:163
> #18 0x00007f40e622f51c in virThreadHelper (data=<optimized out>) at
> ../../../src/util/virthread.c:196
> #19 0x00007f40e5ef2609 in start_thread (arg=<optimized out>) at
> pthread_create.c:477
> #20 0x00007f40e5e19293 in clone () at
> ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
>
> The fix is to either make sure that firstEntryName = NULL; like
> before, or we replace with the upstream call to
> g_steal_pointer(&firstEntryName); which does the same.
>
> static inline gpointer
> g_steal_pointer (gpointer pp)
> {
> gpointer *ptr = (gpointer *) pp;
> gpointer ref;
> ref = *ptr;
> *ptr = NULL;
> return ref;
> }
>
> [Testcase]
>
> Deploy a machine with a NIC that supports SR-IOV. Note, only
> particular NICs will reach the end of virPCIGetNetName().
>
> Install KVM stack:
>
> $ sudo apt-get install qemu-kvm libvirt-daemon-system libvirt-clients
> bridge-utils
>
> Edit /etc/default/grub and add "intel_iommu=on" to the kernel command
> line.
>
> $ sudo update-grub
> $ sudo reboot
>
> Create the VFs via the sysfs node:
>
> $ sudo -s
> # cat /sys/class/net/eno49/device/sriov_totalvfs
> 63
> # echo '7' > /sys/class/net/eno49/device/sriov_numvfs
>
> Next we need to define a virsh network, save the following in
> /tmp/passthrough.xml, changing "eno49" to your network interface.
>
> <network>
> <name>passthrough</name>
> <forward mode='hostdev' managed='yes'>
> <pf dev='eno49'/>
> </forward>
> </network>
>
> $ virsh net-define /tmp/passthrough.xml
> $ virsh net-autostart passthrough
> $ virsh net-start passthrough
>
> We need to make an apparmor rule to enable vfio of our VF device.
>
> Edit /etc/apparmor.d/local/abstractions/libvirt-qemu
>
> Add the line:
>
> /dev/vfio/* rw,
>
> Then restart apparmor:
>
> $ sudo systemctl restart apparmor.service
>
> Next make a Focal VM:
>
> $ sudo apt install uvtool-libvirt
> $ ssh-keygen
> $ uvt-simplestreams-libvirt sync release=focal arch=amd64
> $ uvt-kvm create --cpu 4 --memory 4096 --disk 8 [ --password insecure ]
> focal-vm release=focal arch=amd64
> $ uvt-kvm wait focal-vm
>
> $ uvt-kvm ssh focal-vm # for ssh, key-based authentication.
> $ virsh console focal-vm # for serial console, user ubuntu, password
> above.
>
> Next, edit the virsh xml
>
> $ virsh shutdown focal-vm
> $ virsh edit focal-vm
>
> Add:
>
> <interface type='network'>
> <source network='passthrough'>
> </interface>
>
> Save and reboot the VM.
>
> $ virsh start focal-vm
>
> [Where problems could occur]
>
> If a regression were to occur, it would affect users who use SR-IOV to
> pass through VF devices into KVM guests, which is a large amount of
> our enterprise users.
>
> The fix is a single line change, and simply replaces what was
> existing, but was mistakenly removed. The changes should be safe.
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1943481/+subscriptions
>
>