Bug 87701

Summary:	hard cpu lockup during pppd initialization of vpn
Product:	Networking	Reporter:	Rich Coe (richcoe2)
Component:	Other	Assignee:	Stephen Hemminger (stephen)
Status:	NEEDINFO ---
Severity:	blocking	CC:	alan, xiyou.wangcong
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	3.18.0-rc3	Subsystem:
Regression:	Yes	Bisected commit-id:

Description Rich Coe 2014-11-04 16:35:07 UTC

I did not experience this issue in 3.16 or before.
I did not try 3.17.

I moved from kernel-3.15 to 3.16, and then to kernel 3.18.
When I start forticlientsslvpn on 3.18, the system locks up hard.  No mouse and no keyboard. 

forticlient starts pppd to enable a vpn connection.
Since this is laptop, I don't get a kernel traceback, or OOPS message.

I'm enabling kdump to see if I can get a reliable traceback.
I was first on 3.18.0-rc2, and moved to 3.18.0-rc3 today, and still have the issue.

Comment 1 Cong Wang 2014-11-06 18:25:10 UTC

You don't have to use kdump, enabling CONFIG_LOCKDEP should help, it complains about  deadlocks.

Comment 2 Alan 2014-12-10 17:23:33 UTC

Would need a traceback to make progress on this