Panic: if_simloop: attempted use of a free mbuf!

Robert Watson rwatson at
Fri Nov 28 09:34:17 PST 2003

Silby's patch to fix this was approved by re@ this morning, should go into
the tree shortly.  Basically, the assertion is slightly too agressive as
some callers into BPF "mock up" mbufs to hold data submitted to BPF.  No
doubt this will get cleaned up, but in the mean time the fix is simply to
remove the assertion. 

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at      Network Associates Laboratories

On Fri, 28 Nov 2003, Pawel Jakub Dawidek wrote:

> Hello.
> I'm reaching assertion from /sys/net/if_loop.c:270.
> This is very easy to reproduce:
> First you need to put loopback into promiscuous mode:
> 	# tcpdump -i lo0
> Then try to connect to loopback, for example:
> 	# telnet 22
> Enjoy!:)
> -- 
> Pawel Jakub Dawidek                       pawel at
> UNIX Systems Programmer/Administrator
> Am I Evil? Yes, I Am!           

More information about the freebsd-current mailing list