enabling pf causes socket panics?

With pf enabled, I get panics after only a few minutes of light  
traffic trought the machine. These two I could capture on the console  
(no dumps written because of mirrored swap):

panic: sbsndptr: sockbuf 0xffffff0010005b60 and mbuf  
0xffffff0004cdfe00 clashing
cpuid = 1
KDB: enter: panic
[thread pid 739 tid 100148 ]
Stopped at      kdb_enter+0x3d: movq    $0,0x47ed48(%rip)
db>

panic: sbflush_internal: cc 60 || mb 0 || mbcnt 0
cpuid = 0
KDB: enter: panic
[thread pid 1696 tid 100125 ]
Stopped at      kdb_enter+0x3d: movq    $0,0x47ed48(%rip)
db> bt
Tracing pid 1696 tid 100125 td 0xffffff000499a000
kdb_enter() at kdb_enter+0x3d
panic() at panic+0x17b
sbflush_internal() at sbflush_internal+0x64
sbrelease_internal() at sbrelease_internal+0x1c
sofree() at sofree+0x107
soclose() at soclose+0x118
_fdrop() at _fdrop+0x23
closef() at closef+0x4c
kern_close() at kern_close+0x110
syscall() at syscall+0x1a5
Xfast_syscall() at Xfast_syscall+0xab
--- syscall (6, FreeBSD ELF64, close), rip = 0x800d3c89c, rsp =  
0x7fffffffcbc8, rbp = 0x1b ---

Before enabling pf, the system ran fully stable for two weeks.  
Disabling pf again (pfctl -d) makes it stable again.


Stefan

-- 
Stefan Bethke <stb_at_lassitu.de>   Fon +49 151 14070811