Bug 233837

Summary:	gcore on stopped process causes reboot...
Product:	Base System	Reporter:	Peter Eriksson <peter.x.eriksson>
Component:	kern	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Closed FIXED
Severity:	Affects Many People	CC:	kib, vangyzen
Priority:	---
Version:	11.2-RELEASE
Hardware:	amd64
OS:	Any

Description Peter Eriksson 2018-12-06 21:53:15 UTC

While trying to debug a Samba problem I wanted to grab core-dumps of running winbindd processes, I then noticed that (as root) giving these commands:

# kill -STOP 49049
# gcore -c /var/cores/winbindd.49049 49049

causes FreeBSD 11.2-RELEASE-p5 to reboot immediately. Tried it on two different systems (one old HP D380 G5 and a new Dell PowerEdge R730xd).

I think the "-s" flag to gcore also causes this effect.

Comment 1 Eric van Gyzen freebsd_committer

2018-12-07 15:18:39 UTC

I could not reproduce this on 11.2-STABLE amd64 at r340464 (Nov 15).  I did:

$ sleep 9999 &
$ jobs -l
[1] + 698 Running             sleep 9999
$ kill -STOP 698
[1] + Suspended (signal)      sleep 9999
$ gcore -c sleep.core 698
$ 

Peter, can you try that, using "sleep" specifically?  If that still reboots your system, this is probably fixed in 11-STABLE.

Comment 2 Eric van Gyzen freebsd_committer

2018-12-07 15:20:31 UTC

By the way, did you get a vmcore dump in /var/crash?

Comment 3 Konstantin Belousov freebsd_committer

2018-12-07 15:32:26 UTC

This was fixed in stable/11 by r340290.