bpf_filter() can leak kernel stack contents

[Guy Harris]

    http://seclists.org/fulldisclosure/2010/Nov/89

That's Linux's BPF interpreter, but the same problem exists with the *BSD BPF 
interpreter:

    
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/net/bpf_filter.c.diff?r1=1.21;r2=1.22

    
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/net/bpf_filter.c?rev=1.22;content-type=text%2Fx-cvsweb-markup

Dan's program doesn't directly map to *BSD, but something could probably be 
cooked up.

OpenBSD's fix clears it up.