Double mutex destruction

Hi,

I left development box running 7.0 sitting idle at work overnight and
was greeted with the following panic this morning:

panic: mtx_lock() of destroyed mutex _at_ ../../../net/route.c:1303
cpuid = 1
KDB: enter: panic
[thread pid 4088 tid 100128 ]
Stopped at      kdb_enter+0x32: leave
db> bt
Tracing pid 4088 tid 100128 td 0xc5539cc0
kdb_enter(c07c56bd,1,c07c4619,f199f9bc,1,...) at kdb_enter+0x32
panic(c07c4619,c07d2ce5,517,507,c5386a7c,...) at panic+0x124
_mtx_lock_flags(c5aeb510,0,c07d2ce5,517,f199fa28,...) at _mtx_lock_flags+0x65
rt_check(f199fa20,f199fa3c,c541ec30,c080a6c4,c07d2cee,...) at rt_check+0x111
arpresolve(c51e4000,c5584bb8,c5587d00,c541ec30,f199fa56,...) at arpresolve+0xb0
ether_output(c51e4000,c5587d00,c541ec30,c5584bb8,c5539cc0,...) at ether_output+0x7e
ip_output(c5587d00,0,f199fac4,0,0,...) at ip_output+0x9f5
udp_send(c5a72000,0,c5587d00,c5a17970,0,...) at udp_send+0x597
sosend_dgram(c5a72000,c5a17970,f199fbe8,c5587d00,0,...) at sosend_dgram+0x351
sosend(c5a72000,c5a17970,f199fbe8,0,0,...) at sosend+0x54
kern_sendit(c5539cc0,4,f199fc64,0,0,...) at kern_sendit+0x104
sendit(0,28228a34,0,c5a17970,10,...) at sendit+0x182
sendto(c5539cc0,f199fcfc,18,c07c1d9e,c0804e18,...) at sendto+0x4f
syscall(f199fd38) at syscall+0x29a
Xint0x80_syscall() at Xint0x80_syscall+0x20
--- syscall (133, FreeBSD ELF32, sendto), eip = 0x28152f23, esp = 0xbfbfe2cc, ebp = 0xbfbfe3e8 ---


Is this one known? Unfortunately, vmcore from this panic got garbled somehow.

--
Alexander Kabaev