Kernel panic with if_sf.ko

Robert Watson rwatson at
Wed Jul 1 21:42:48 UTC 2009

On Wed, 1 Jul 2009, Jung-uk Kim wrote:

>>> Last time I checked, bpf(4) with MAC caused a similar problem when it is 
>>> destroying bpf descriptor label.  GENERIC includes MAC by default now. 
>>> If you don't need MAC, try removing "options MAC" from your kernel 
>>> configuration.
>> I was not aware of this problem -- could you provide some more details? 
>> Any panic caused by having MAC in the kernel is a bug...
> It was about a month ago.  I had funny impression that you and sam were 
> working on it cause it started happening when sam added bpf detach event 
> handler and MAC was enabled by default.  Any way, I will let you know if I 
> can reproduce the problem.

There have been a number of tear-down related races for ifnets, more of which 
are closed now than before the last few weeks, but none MAC-related as far as 
I'm aware.  If it recurs, please let me know and I'm happy to help investigate 
(MAC-related or otherwise).

Robert N M Watson
Computer Laboratory
University of Cambridge

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