kern/83943: [panic!] on FreeBSD 6.0-BETA1 with nve

[Gabor Kovesdan]

>Number:         83943
>Category:       kern
>Synopsis:       [panic!] on FreeBSD 6.0-BETA1 with nve
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Jul 23 10:50:19 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Gabor Kovesdan <gabor.kovesdan at t-hosting.hu>
>Release:        FreeBSD 6.0-BETA1 amd64
>Organization:
>Environment:
System: FreeBSD dream 6.0-BETA1 FreeBSD 6.0-BETA1 #0: Tue Jul 12 09:02:51 UTC 2005 root at rat.samsco.home:/usr/obj/usr/src/sys/GENERIC amd64


>Description:
FreeBSD has a kernel panic when using nve network interface. Unfortunately
I'm not so familiar with kernel debugging and kernel bug reporting,
and haven't found a good howto about this topic,
but I was able to make a trace with ddb and copied it by hand:

panic: nve_ifstart: attempted use of a free mbuf!
cpuid=0
KDB: enter: panic
[thread pid 35 tid 100034]
Stopped at kdb_enter+0x2f: nop

db> trace
Tracing pid 35 tid 100034 td 0xffffff001ed224c0
kdb_enter() at kbd_enter+0x2f
panic() at panic+0x3f7
nve_ifstart() at nve_ifstart+0x3f7
ether_output_frame() at ether_output_frame+0x390
ip_output() at ip_output+0xb17
tcp_output() at tcp_output+0x9ec
tcp_input() at tcp_input+0x1789
ip_input() at ip_input+0x10d
netisr_processqueue() at netisr_processqueue+0x17
swi_net() at swi_net+0xa8
ithread_loop() at ithread_loop+0xc8
fork_exit() at fork_exit+0xbb
fork_trampoline() at fork_trampoline+0xe
--- trap 0, rip = 0, rsp = 0xffffffff951aed00, rbp = 0 ---

I hope this helps, if it isn't please let me know what kind of information
to provide and how to obtain it at the next crash.
I've had this problem several times and the panic and the trace output
was exactly the same.
I've also got a vmcore dump, but it is hard to make it online, since
I have 512 MB of memory and the bug is in my network interface user for
internetworking, it would be difficult to upload it to my webpage.

>How-To-Repeat:
It comes randomly when using nve.

>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted: