[Bug 1929122] Re: networkd crashes when advertising blackhole route thru BGP

[Dan Streetman]

never mind, i believe it's fixed with an upstream commit, and a fixed package is building in this ppa:
https://launchpad.net/~ddstreet/+archive/ubuntu/systemd

i'll upload patched systemd later this week; let me know if that doesn't
fix this for you

** Description changed:

+ [impact]
+ 
+ systemd-networkd crashes due to assertion failure
+ 
+ [test case]
+ 
+ run systemd-networkd and FRR as described in original description below
+ 
+ [regression potential]
+ 
+ and regression would likely involve incorrectly configured routes
+ 
+ [scope]
+ 
+ this is needed only for f
+ 
+ this is fixed upstream by commit
+ 25b831bac8a5e545e1eda5199392c11c7aed4e42 which is first in v246, so this
+ is fixed in groovy and later
+ 
+ the code involved in this isn't present in b so this doesn't apply there
+ 
+ [original description]
+ 
  lsb_release -rd
  Description:	Ubuntu 20.04.2 LTS
  Release:	20.04
  
  apt-cache policy systemd
  systemd:
-   Installed: 245.4-4ubuntu3.6
+   Installed: 245.4-4ubuntu3.6
  
  [Impact]
  Networkd crashes when a blackhole route (route aggregation is installed as a blackhole route) is advertised via FRR.
  
  [Fix]
  networkd should not crash
  
  [Test case]
  Bug was reported to systemd (not accepted because systemd version too old) where a test case is described: https://github.com/systemd/systemd/issues/19648 Lower in the comment you can find the full debug log from networkd.
  
  Here you can see the core dump:
  https://drive.google.com/file/d/1tCKiOSnGkLbx3w9du5_NNepkOQZC_hx7/view?usp=sharing
  
  For convenience I also packed the relevant parts of the prod env in a
  vagrant box showing the issue: vagrant init matijavizintin/networkd-
  debug
  
  After some more testing i noticed that immediately after the route is
  being advertised, networkd detects the change and crashes with
  "Assertion 'ifindex' failed at src/network/networkd-link.c:757, function
  link_get(). Aborting."
  
  Steps how it happens:
  1. networkd is running
  2. frr is started without advertising the aggregated address
  3. add aggregated address and reload frr
  4. blackhole route is installed and networkd crashes with the error above

** Also affects: systemd (Ubuntu Focal)
   Importance: Undecided
       Status: New

** Also affects: systemd (Ubuntu Bionic)
   Importance: Undecided
       Status: New

** Changed in: systemd (Ubuntu Bionic)
       Status: New => Invalid

** Changed in: systemd (Ubuntu)
       Status: New => Fix Released

** Changed in: systemd (Ubuntu Focal)
   Importance: Undecided => Medium

** Changed in: systemd (Ubuntu Focal)
     Assignee: (unassigned) => Dan Streetman (ddstreet)

** Changed in: systemd (Ubuntu Focal)
       Status: New => In Progress

-- 
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https://bugs.launchpad.net/bugs/1929122

Title:
  networkd crashes when advertising blackhole route thru BGP

Status in systemd package in Ubuntu:
  Fix Released
Status in systemd source package in Bionic:
  Invalid
Status in systemd source package in Focal:
  In Progress

Bug description:
  [impact]

  systemd-networkd crashes due to assertion failure

  [test case]

  run systemd-networkd and FRR as described in original description
  below

  [regression potential]

  and regression would likely involve incorrectly configured routes

  [scope]

  this is needed only for f

  this is fixed upstream by commit
  25b831bac8a5e545e1eda5199392c11c7aed4e42 which is first in v246, so
  this is fixed in groovy and later

  the code involved in this isn't present in b so this doesn't apply
  there

  [original description]

  lsb_release -rd
  Description:	Ubuntu 20.04.2 LTS
  Release:	20.04

  apt-cache policy systemd
  systemd:
    Installed: 245.4-4ubuntu3.6

  [Impact]
  Networkd crashes when a blackhole route (route aggregation is installed as a blackhole route) is advertised via FRR.

  [Fix]
  networkd should not crash

  [Test case]
  Bug was reported to systemd (not accepted because systemd version too old) where a test case is described: https://github.com/systemd/systemd/issues/19648 Lower in the comment you can find the full debug log from networkd.

  Here you can see the core dump:
  https://drive.google.com/file/d/1tCKiOSnGkLbx3w9du5_NNepkOQZC_hx7/view?usp=sharing

  For convenience I also packed the relevant parts of the prod env in a
  vagrant box showing the issue: vagrant init matijavizintin/networkd-
  debug

  After some more testing i noticed that immediately after the route is
  being advertised, networkd detects the change and crashes with
  "Assertion 'ifindex' failed at src/network/networkd-link.c:757,
  function link_get(). Aborting."

  Steps how it happens:
  1. networkd is running
  2. frr is started without advertising the aggregated address
  3. add aggregated address and reload frr
  4. blackhole route is installed and networkd crashes with the error above

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