Description

MGD core is generated and the session terminated unexpectedly on a cRPD system.  The router is configured for ISIS with a group:
 

root@crpd2# show protocols isis       

apply-groups TP_ISISPEER;

interface lo0.0 {

  lsp-interval 500;

  passive;

}

lo0.0 is then removed from ISIS:
 

root@crpd2# delete protocols isis interface lo0.0 

error: session failure: unexpected termination

error: remote side unexpectedly closed connection
 

And, MGD cores:
 

Dec 14 21:46:50 crpd-deployment-5dc9d6bfc7-29vrz : <14>1 2023-12-14T21:46:50.645Z crpd01-os rpd - RPD_ISIS_ADJUP [junos@- isis-level="2" neighbor-system-id="RCR01A3SCCC" interface-name="net3.100"] IS-IS new L2 adjacency to RCR01A3SCCC on net3.100

Dec 14 21:46:50 crpd-deployment-5dc9d6bfc7-29vrz : <190>1 2023-12-14T21:46:50.827Z crpd01-os mgd 744 UI_CMDLINE_READ_LINE [junos@- username="lab" command="delete protocols isis interface lo0.0 "] User 'lab', command 'delete protocols isis interface lo0.0 '

Dec 14 21:46:50 crpd-deployment-5dc9d6bfc7-29vrz : <182>1 2023-12-14T21:46:50.827Z crpd01-os mgd 744 UI_CFG_AUDIT_OTHER [junos@- username="lab" action="delete" pathname="[protocols isis interface lo0.0\]" delimiter="" value=""] User 'lab' delete: [protocols isis interface lo0.0]

Dec 14 21:46:55 crpd-deployment-5dc9d6bfc7-29vrz kernel: mgd[224280]: segfault at 4 ip 00007fb54b5e7c0a sp 00007fff47326120 error 4 in libddl-access.so.1[7fb54b55c000+b7000]

Dec 14 21:46:55 crpd-deployment-5dc9d6bfc7-29vrz kernel: Code: 48 89 c6 48 c1 ee 15 81 e6 f8 1f 00 00 48 8b 14 32 48 85 d2 74 0f 48 c1 e8 09 25 f8 7f 00 00 48 8b 04 02 eb 02 31 c0 48 01 c8 <41> 0f b6 4f 04 66 39 48 2a 0f 86 b1 00 00 00 0f b7 f1 48 85 c0 0f

Dec 14 21:46:51 crpd-deployment-5dc9d6bfc7-29vrz sshd[739]: syslogin_perform_logout: logout() returned an error

Dec 14 21:46:51 crpd-deployment-5dc9d6bfc7-29vrz sshd[742]: Received disconnect from 192.168.255.57 port 56288:11: disconnected by user

Dec 14 21:46:51 crpd-deployment-5dc9d6bfc7-29vrz sshd[742]: Disconnected from user lab 192.168.255.57 port 56288

Dec 14 21:46:51 crpd-deployment-5dc9d6bfc7-29vrz sshd[739]: in openpam_dispatch(): calling pam_sm_close_session() in /junos/lib/pam_permit.so.2

Dec 14 21:46:51 crpd-deployment-5dc9d6bfc7-29vrz sshd[739]: in openpam_dispatch(): /junos/lib/pam_permit.so.2: pam_sm_close_session(): Success

Dec 14 21:46:51 crpd-deployment-5dc9d6bfc7-29vrz sshd[739]: in openpam_dispatch(): calling pam_sm_setcred() in /junos/lib/pam_unix.so

 

lab@crpd01-os> show system core-dumps

-rw------- 1 root root 750727168 Dec 14 21:46 /var/crash/core-mgd.744.crpd01-os.1702590410

Symptoms

MGD core dump without a commit on cRPD

Solution

Issue is fixed in PR1781210:

https://prsearch.juniper.net/PR1781210

The fix is to add a null check for the process to check interface-range as it is not supported in cRPD.

Modification History

2024-02-26 : Article Created
2024-07-29:  Adjusted content for external publishing

Related Information

https://gnats.juniper.net/web/default/1781210#description_tab