kern/49137: Multicast sockets can trigger kernel panic

[tron%zhadum.org.uk@localhost]

>Number:         49137
>Category:       kern
>Synopsis:       Multicast sockets can trigger kernel panic
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Aug 21 19:00:00 +0000 2014
>Originator:     Matthias Scheler
>Release:        NetBSD 7.0_BETA 2014-08-20 sources
>Organization:
Matthias Scheler                                 https://zhadum.org.uk/
>Environment:
System: NetBSD colwyn.zhadum.org.uk 7.0_BETA NetBSD 7.0_BETA (GENERIC) #0: Wed 
Aug 20 13:44:09 BST 2014 
tron%lyssa.zhadum.org.uk@localhost:/export/scratch/tron/obj/sys/arch/amd64/compile/GENERIC
 amd64
Architecture: x86_64
Machine: amd64
>Description:
When I tried to stop "mediatomb" on a system freshly upgraded to
NetBSD 7.0_BETA it paniced the kernel. Here is what "savecore" printed out:

Aug 21 18:57:49 colwyn savecore: reboot after panic: panic: kernel diagnostic 
assertion "mutex_owned(softnet_lock)" failed: file 
"/src/NetBSD-7/src/sys/netinet/igmp.c", line 636

I've got a crash dump but it doesn't seem to be useful:

tron@colwyn:/var/crash#ls -l netbsd.0*
-rw-------  1 root  wheel    1467248 Aug 21 18:57 netbsd.0
-rw-------  1 root  wheel  387658264 Aug 21 18:57 netbsd.0.core
tron@colwyn:/var/crash#gdb netbsd.0
GNU gdb (GDB) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64--netbsd".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
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<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from netbsd.0...(no debugging symbols found)...done.
(gdb) target kvm netbsd.0.core
<unavailable> in ?? ()
(gdb) where
#0  <unavailable> in ?? ()
Backtrace stopped: not enough registers or memory available to unwind further

>How-To-Repeat:
cd pkgsrc/multimedia/mediatomb
make bin-install
/usr/pkg/share/examples/rc.d/mediatomb onestart
/usr/pkg/share/examples/rc.d/mediatomb onestop

>Fix:
Not known.