if_ovpn: Fatal trap 12: page fault while in kernel mode

I was trying to rearchitect some overly-complicated networking on a 
server and settled on a combination of OpenVPN and pf's reply-to to 
route the traffic properly. Everything was working as expected and I 
went to bed only to wake up and realize it had been crash looping all night.

I did some digging and thought that perhaps this commit was the fix, so 
I updated from 15.0-RELEASE to 15.1-RELEASE: 
https://cgit.freebsd.org/src/commit/sys/net/if_ovpn.c?h=stable/15&id=04a7134c1e92c7752ffdc665f99ae26db70866c0

Unfortunately it did not fix it and I have a feeling that a similar bug 
is lurking elsewhere in the if_ovpn driver. Can someone clarify if this 
is an outstanding bug that needs further investigation or if it's 
potentially already addressed in CURRENT?

Thanks


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x0
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff81093c4a
stack pointer           = 0x28:0xfffffe0067d621e0
frame pointer           = 0x28:0xfffffe0067d621e0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                         = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 12 (irq129: ahci0)
rdi: fffff801338840ee rsi: 0000000000000000 rdx: 0000000000000267
rcx: 0000000000000267  r8: 00000000000000c1  r9: fffff800312f7000
rax: fffff801338840ee rbx: fffff80001eb6200 rbp: fffffe0067d621e0
r10: fffff80031259000 r11: fffff8003123248c r12: 0000000000000001
r13: fffff80001de2700 r14: fffff80001de2700 r15: fffff80001b21100
trap number             = 12
panic: page fault
cpuid = 0
time = 1782496026
KDB: stack backtrace:
#0 0xffffffff80bd609d at kdb_backtrace+0x5d
#1 0xffffffff80b86c06 at vpanic+0x136
#2 0xffffffff80b86ac3 at panic+0x43
#3 0xffffffff81097fcd at trap_pfault+0x37d
#4 0xffffffff8106e568 at calltrap+0x8
#5 0xffffffff80c265cb at m_unshare+0x36b
#6 0xffffffff82e9ed7b at ovpn_output+0x2b
#7 0xffffffff82e4ffdf at pf_route+0x89f
#8 0xffffffff82e4693a at pf_test+0xd0a
#9 0xffffffff82e62e6e at pf_check_out+0x2e
#10 0xffffffff80cda688 at pfil_mbuf_out+0x38
#11 0xffffffff80d59e2e at ip_output+0xc7e
#12 0xffffffff8255f92b at rack_output+0x4afb
#13 0xffffffff80d85602 at tcp_usr_ready+0x182
#14 0xffffffff80b84da5 at sendfile_iodone+0x115
#15 0xffffffff80f534df at vnode_pager_generic_getpages_done_async+0x3f
#16 0xffffffff80c510f1 at bufdone+0x41
#17 0xffffffff80abd317 at g_io_deliver+0x2a7
Timeout initializing vt_vga
Uptime: 1h14m9s




Mark