kern/49956: netbsd-7 panics, ipv6-related

[bouyer%antioche.eu.org@localhost]

>Number:         49956
>Category:       kern
>Synopsis:       netbsd-7 panics, ipv6-related
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 09 13:40:01 +0000 2015
>Originator:     Manuel Bouyer
>Release:        NetBSD 7.0_BETA
>Organization:
>Environment:
System: NetBSD antioche.lip6.fr 7.0_BETA NetBSD 7.0_BETA (ANTIOCHE7-64) #0: Thu Feb 12 09:58:20 CET 2015 bouyer@hop:/dsk/l1/misc/bouyer/tmp/amd64/obj/dsk/l1/misc/bouyer/netbsd-7/src/sys/arch/amd64/compile/ANTIOCHE7-64 amd64
Architecture: x86_64
Machine: amd64
>Description:
	I've seen this several times now, on the host running mainly 
	*.fr.netbsd.org:
panic: kernel diagnostic assertion "(m)->m_type != MT_FREE" failed: file "/dsk/l1/misc/bouyer/netbsd-7/src/sys/kern/uipc_mbuf.c", line 652 
cpu0: Begin traceback...
vpanic() at netbsd:vpanic+0x13c
kern_assert() at netbsd:kern_assert+0x4f
m_freem() at netbsd:m_freem+0xa7
ipf_fastroute() at netbsd:ipf_fastroute+0x397
ipf_send_ip() at netbsd:ipf_send_ip+0x13c
ipf_send_icmp_err() at netbsd:ipf_send_icmp_err+0x1fa
ipf_check() at netbsd:ipf_check+0x88c
pfil_run_hooks() at netbsd:pfil_run_hooks+0xc4
ip6_input() at netbsd:ip6_input+0x1bb
ip6intr() at netbsd:ip6intr+0x45
softint_dispatch() at netbsd:softint_dispatch+0xd3
DDB lost frame for netbsd:Xsoftintr+0x4f, trying 0xfffffe810e95eff0
Xsoftintr() at netbsd:Xsoftintr+0x4f
--- interrupt ---

This could mean that the mbuf is freed twice.


>How-To-Repeat:
	run a ipv6-connected netbsd-7 host with ipf enabled and 
	'return-icmp' rules ?
>Fix:
	workaround: I removed "return-icmp" from my ipf6.conf for now,
	I don't know yet if this fixes the issue