@r-2ohn-d please do write up a test case for @vorlon, thanks

You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to systemd in Ubuntu.

  systemd-networkd crashes with invalid pointer

Status in systemd package in Ubuntu:
  Fix Released
Status in systemd source package in Bionic:

Bug description:

  systemd-networkd double-free causes crash under some circumstances,
  such as adding/removing ip rules

  [test case]

  see original description

  [regression potential]

  this strdup's strings during addition of routing policy rules, so any
  regression would likely occur when adding/modifying/removing ip rules,
  possibly including networkd segfault or failure to add/remove/modify
  ip rules.


  this is needed for bionic.

  this is fixed by upstream commit
  eeab051b28ba6e1b4a56d369d4c6bf7cfa71947c which is included starting in
  v240, so this is already included in Focal and later.

  I did not research what original commit introduced the problem, but
  the reporter indicates this did not happen for Xenial so it's unlikely
  this is a problem in Xenial or earlier.

  [original description]

  This is a serious regression with systemd-networkd that I ran in to
  while setting up a NAT router in AWS. The AWS AMI ubuntu/images/hvm-
  ssd/ubuntu-bionic-18.04-amd64-server-20200131 with
  systemd-237-3ubuntu10.33 does NOT have the problem, but the next most
  recent AWS AMI ubuntu/images/hvm-ssd/ubuntu-
  bionic-18.04-amd64-server-20200311 with systemd-including
  237-3ubuntu10.39 does.

  Also, a system booted from the (good) 20200131 AMI starts showing the
  problem after updating only systemd (to 237-3ubuntu10.41) and its
  direct dependencies (e.g. 'apt-get install systemd'). So I'm fairly
  confident that a change to the systemd package between
  237-3ubuntu10.33 and 237-3ubuntu10.39 introduced the problem and it is
  still present.

  On the NAT router I use three interfaces and have separate routing
  tables for admin and forwarded traffic. Things come up fine initially
  but every 30-60 minutes (DHCP lease renewal time?) one or more
  interfaces is reconfigured and most of the time systemd-networkd will
  crash and need to be restarted. Eventually the system becomes
  unreachable when the default crash loop backoff logic prevents the
  network service from being restarted at all. The log excerpt attached
  illustrates the crash loop.

  Also including the netplan and networkd config files below.

  # grep . /etc/netplan/*
  /etc/netplan/50-cloud-init.yaml:# This file is generated from information 
provided by the datasource.  Changes
  /etc/netplan/50-cloud-init.yaml:# to it will not persist across an instance 
reboot.  To disable cloud-init's
  /etc/netplan/50-cloud-init.yaml:# network configuration capabilities, write a 
/etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
  /etc/netplan/50-cloud-init.yaml:# network: {config: disabled}
  /etc/netplan/50-cloud-init.yaml:    version: 2
  /etc/netplan/50-cloud-init.yaml:    ethernets:
  /etc/netplan/50-cloud-init.yaml:        ens5:
  /etc/netplan/50-cloud-init.yaml:            dhcp4: true
  /etc/netplan/50-cloud-init.yaml:            match:
  /etc/netplan/50-cloud-init.yaml:                macaddress: xx:xx:xx:xx:xx:xx
  /etc/netplan/50-cloud-init.yaml:            set-name: ens5
  /etc/netplan/99_config.yaml:  version: 2
  /etc/netplan/99_config.yaml:  renderer: networkd
  /etc/netplan/99_config.yaml:  ethernets:
  /etc/netplan/99_config.yaml:    ens6:
  /etc/netplan/99_config.yaml:      match:
  /etc/netplan/99_config.yaml:        macaddress: yy:yy:yy:yy:yy:yy
  /etc/netplan/99_config.yaml:      dhcp4: true
  /etc/netplan/99_config.yaml:      dhcp4-overrides:
  /etc/netplan/99_config.yaml:        use-routes: false
  /etc/netplan/99_config.yaml:    ens7:
  /etc/netplan/99_config.yaml:      match:
  /etc/netplan/99_config.yaml:        macaddress: zz:zz:zz:zz:zz:zz
  /etc/netplan/99_config.yaml:      mtu: 1500
  /etc/netplan/99_config.yaml:      dhcp4: true
  /etc/netplan/99_config.yaml:      dhcp4-overrides:
  /etc/netplan/99_config.yaml:        use-mtu: false
  /etc/netplan/99_config.yaml:        use-routes: false

  # grep . /etc/networkd-dispatcher/*/*
  /etc/networkd-dispatcher/configured.d/nat:# Do additional configuration for 
the inside and outside interfaces
  /etc/networkd-dispatcher/configured.d/nat:# route table used for 
forwarded/routed/natted traffic
  /etc/networkd-dispatcher/configured.d/nat:if [ "${IFACE}" = "ens6" ]; then
  /etc/networkd-dispatcher/configured.d/nat:  # delete link-local route for 
inside in default table
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip route delete 
2>/dev/null || true
  /etc/networkd-dispatcher/configured.d/nat:  # add link-local route for inside 
in table 99
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip route replace dev ens6 scope link src table ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  # add routes to VPC cidrs via 
inside gateway in table 99
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip route replace via table ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  # add rules to use table 99
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip rule add iif  ens6 
lookup ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip rule add oif  ens6 
lookup ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip rule add from lookup ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:elif [ "${IFACE}" = "ens7" ]; then
  /etc/networkd-dispatcher/configured.d/nat:  # delete link-local route for 
outside in default table
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip route delete 
2>/dev/null || true
  /etc/networkd-dispatcher/configured.d/nat:  # add link-local route for 
outside in table 99
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip route replace dev ens7 scope link src table ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  # add default route via outside 
gateway in table 99
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip route replace default 
via table ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  # add rules to use table 99
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip rule add iif  ens7 
lookup ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip rule add oif  ens7 
lookup ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/ip rule add from lookup ${FWD_TABLE}
  /etc/networkd-dispatcher/configured.d/nat:  # add rules to use the inet route 
for local traffic but only if it's not destined for an RFC1918 private range
  /etc/networkd-dispatcher/configured.d/nat:  # IMPORTANT: order matters; the 
priority of rules is reverse of the order in which they are added.
  /etc/networkd-dispatcher/configured.d/nat:  # so the default/fallback is 
added first and then the local overrides.
  /etc/networkd-dispatcher/configured.d/nat:  #/sbin/ip rule add iif lo lookup 
  /etc/networkd-dispatcher/configured.d/nat:  #ip rule add to iif lo 
lookup main
  /etc/networkd-dispatcher/configured.d/nat:  #ip rule add to iif 
lo lookup main
  /etc/networkd-dispatcher/configured.d/nat:  #ip rule add to 
iif lo lookup main
  /etc/networkd-dispatcher/configured.d/nat:  # ensure the forward policy is 
  /etc/networkd-dispatcher/configured.d/nat:  iptables -P FORWARD ACCEPT
  /etc/networkd-dispatcher/configured.d/nat:  # configure iptables to do NAT
  /etc/networkd-dispatcher/configured.d/nat:  /sbin/iptables -t nat -I 
POSTROUTING 1 -o ens7 -j SNAT --to-source
  /etc/networkd-dispatcher/configured.d/nat:  # clean up any other rules
  /etc/networkd-dispatcher/configured.d/nat:  while /sbin/iptables -t nat -D 
POSTROUTING 2 2>/dev/null; do :; done
  /etc/networkd-dispatcher/configuring.d/nat:# Tear down existing ip rules so 
they aren't duplicated
  /etc/networkd-dispatcher/configuring.d/nat:if [ "${IFACE}" = "ens6" ]; then
  /etc/networkd-dispatcher/configuring.d/nat:  # flush any existing rules 
referenceing this interface
  /etc/networkd-dispatcher/configuring.d/nat:  OLDIFS="${IFS}"
  /etc/networkd-dispatcher/configuring.d/nat:  IFS="
  /etc/networkd-dispatcher/configuring.d/nat:  for rule in `ip rule show|egrep 
"ens6|" | cut -d: -f2-`; do
  /etc/networkd-dispatcher/configuring.d/nat:    IFS="${OLDIFS}"
  /etc/networkd-dispatcher/configuring.d/nat:    ip rule delete ${rule}
  /etc/networkd-dispatcher/configuring.d/nat:  done
  /etc/networkd-dispatcher/configuring.d/nat:  IFS="${OLDIFS}"
  /etc/networkd-dispatcher/configuring.d/nat:elif [ "${IFACE}" = "ens7" ]; then
  /etc/networkd-dispatcher/configuring.d/nat:  # flush any existing rules 
referencing this interface
  /etc/networkd-dispatcher/configuring.d/nat:  OLDIFS="${IFS}"
  /etc/networkd-dispatcher/configuring.d/nat:  IFS="
  /etc/networkd-dispatcher/configuring.d/nat:  for rule in `ip rule show|egrep 
"ens7||iif lo" | cut -d: -f2-`; do
  /etc/networkd-dispatcher/configuring.d/nat:    IFS="${OLDIFS}"
  /etc/networkd-dispatcher/configuring.d/nat:    ip rule delete ${rule}
  /etc/networkd-dispatcher/configuring.d/nat:  done
  /etc/networkd-dispatcher/configuring.d/nat:  IFS="${OLDIFS}"

  ProblemType: Bug
  DistroRelease: Ubuntu 18.04
  Package: systemd 237-3ubuntu10.39
  ProcVersionSignature: Ubuntu 4.15.0-1060.62-aws 4.15.18
  Uname: Linux 4.15.0-1060-aws x86_64
  ApportVersion: 2.20.9-0ubuntu7.11
  Architecture: amd64
  Date: Wed Jun  3 21:24:28 2020
  Ec2AMI: ami-0238c6e72a7e906fc
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1b
  Ec2InstanceType: c5n.large
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  Lsusb: Error: command ['lsusb'] failed with exit code 1:
  MachineType: Amazon EC2 c5n.large
   PATH=(custom, no user)
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-1060-aws 
root=LABEL=cloudimg-rootfs ro console=tty1 console=ttyS0 
  SourcePackage: systemd
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 10/16/2017
  dmi.bios.vendor: Amazon EC2
  dmi.bios.version: 1.0
  dmi.board.asset.tag: i-0c058310742990713
  dmi.board.vendor: Amazon EC2
  dmi.chassis.asset.tag: Amazon EC2
  dmi.chassis.type: 1
  dmi.chassis.vendor: Amazon EC2
  dmi.product.name: c5n.large
  dmi.sys.vendor: Amazon EC2

To manage notifications about this bug go to:

Mailing list: https://launchpad.net/~touch-packages
Post to     : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to