An MX saw multiple core dumps in mustd:

root@re0-mx1> show system core-dumps no-forwarding

/var/crash/*core*: No such file or directory

-rw------- 1 root wheel  82820349 Jun 18 08:24 /var/tmp/mustd.core.0.gz

-rw------- 1 root wheel  83086703 Jun 18 09:33 /var/tmp/mustd.core.1.gz

-rw------- 1 root wheel  82949896 Jun 18 10:07 /var/tmp/mustd.core.2.gz

-rw------- 1 root wheel  80779865 Jun 18 08:04 /var/tmp/mustd.core.3.gz

-rw------- 1 root wheel  83149990 Jun 18 08:08 /var/tmp/mustd.core.4.gz

/var/tmp/pics/*core*: No such file or directory

/var/crash/kernel.*: No such file or directory

/var/jails/rest-api/tmp/*core*: No such file or directory

/tftpboot/corefiles/*core*: No such file or directory

total files: 5

The cores are all tied to commits:

Jun 18 08:03:49 re0-mx1 mgd[53233]: UI_COMMIT: User 'root' requested 'commit' operation (comment: none)

Jun 18 08:03:59 re0-mx1 mustd[53433]: ../../../../../../src/ui/lib/access/model.c:dom_invalid_model:239: insist 'model > 0 && model <= MODEL_MAX' failed

Jun 18 08:04:33 re0-mx1 mgd[53233]: UI_CHILD_SIGNALED: Child received signal: PID 53433, signal Abort trap, core dumped, command='/usr/sbin/mustd'

The commit is a large change to the prefix-list configuration used by BGP:

/* Group prefix lists IPv4 */

policy-options {

replace:

 prefix-list pl-import-v4 {

  1.179.112.0/20;

  5.62.21.0/24;

With 300,000 lines of changes.

Core dump in mustd when commiting a large change to the router configuration.

Problem is tracked via PR1818692:
 

https://prsearch.juniper.net/PR1818692
 

As a workaround, the changes can be split into multiple smaller commits.