kernel panic when shutting down ppp

[Avernar]

I'm running ppp for a pppoe connection in a vnet jail on 11.0-RELEASE.
I've been getting a panic when shutting down ppp sometimes.

Any ideas what might be causing this?

Fatal trap 12: page fault while in kernel mode
cpuid = 3; apic id = 06
fault virtual address    = 0x0
fault code        = supervisor read data, page not present
instruction pointer    = 0x20:0xffffffff80c20f09
stack pointer            = 0x28:0xfffffe04663f7470
frame pointer            = 0x28:0xfffffe04663f75c0
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        = 3352 (ppp)
trap number        = 12
panic: page fault
cpuid = 3

(kgdb) bt
#0  doadump (textdump=<value optimized out>) at pcpu.h:221
#1  0xffffffff80ae6889 in kern_reboot (howto=260) at
/usr/src/sys/kern/kern_shutdown.c:366
#2  0xffffffff80ae6e3b in vpanic (fmt=<value optimized out>, ap=<value
optimized out>) at /usr/src/sys/kern/kern_shutdown.c:759
#3  0xffffffff80ae6c73 in panic (fmt=0x0) at
/usr/src/sys/kern/kern_shutdown.c:690
#4  0xffffffff80ff1d31 in trap_fatal (frame=0xfffffe04663f73c0, eva=0)
at /usr/src/sys/amd64/amd64/trap.c:841
#5  0xffffffff80ff1f23 in trap_pfault (frame=0xfffffe04663f73c0,
usermode=0) at /usr/src/sys/amd64/amd64/trap.c:691
#6  0xffffffff80ff14cc in trap (frame=0xfffffe04663f73c0) at
/usr/src/sys/amd64/amd64/trap.c:442
#7  0xffffffff80fd4641 in calltrap () at
/usr/src/sys/amd64/amd64/exception.S:236
#8  0xffffffff80c20f09 in sysctl_dumpentry (rn=0xfffff8014e403dd0,
vw=0xfffffe04663f7618) at /usr/src/sys/net/rtsock.c:1543
#9  0xffffffff80c1a910 in rn_walktree (h=<value optimized out>,
f=<value optimized out>, w=<value optimized out>) at
/usr/src/sys/net/radix.c:1094
#10 0xffffffff80c20832 in sysctl_rtsock (oidp=<value optimized out>,
arg1=<value optimized out>, arg2=<value optimized out>, req=<value
optimized out>) at /usr/src/sys/net/rtsock.c:1894
#11 0xffffffff80af508f in sysctl_root_handler_locked
(oid=0xffffffff81a23600, arg1=0xfffffe04663f7928, arg2=4,
req=0xfffffe04663f7858, tracker=0xfffffe04663f77d0) at
/usr/src/sys/kern/kern_sysctl.c:165
#12 0xffffffff80af47ff in sysctl_root (arg1=<value optimized out>,
arg2=<value optimized out>) at /usr/src/sys/kern/kern_sysctl.c:1876
#13 0xffffffff80af4dd9 in userland_sysctl (td=0xfffff8014eaa0000,
name=0xfffffe04663f7920, namelen=6, old=<value optimized out>,
oldlenp=<value optimized out>, inkernel=<value optimized out>,
new=<value optimized out>,
    newlen=<value optimized out>, retval=0xfffff8006e059000, flags=0)
at /usr/src/sys/kern/kern_sysctl.c:1979
#14 0xffffffff80af4bb4 in sys___sysctl (td=0xfffff8014eaa0000,
uap=0xfffffe04663f7a40) at /usr/src/sys/kern/kern_sysctl.c:1906
#15 0xffffffff80ff268e in amd64_syscall (td=<value optimized out>,
traced=0) at subr_syscall.c:135
#16 0xffffffff80fd492b in Xfast_syscall () at
/usr/src/sys/amd64/amd64/exception.S:396
#17 0x0000000801dd6f5a in ?? ()
Current language:  auto; currently minimal
(kgdb) frame 8
#8  0xffffffff80c20f09 in sysctl_dumpentry (rn=0xfffff8014e403dd0,
vw=0xfffffe04663f7618) at /usr/src/sys/net/rtsock.c:1543
1543            info.rti_info[RTAX_IFP] = rt->rt_ifp->if_addr->ifa_addr;
(kgdb) list
1538        info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
1539        info.rti_info[RTAX_NETMASK] = rtsock_fix_netmask(rt_key(rt),
1540            rt_mask(rt), &ss);
1541        info.rti_info[RTAX_GENMASK] = 0;
1542        if (rt->rt_ifp) {
1543            info.rti_info[RTAX_IFP] = rt->rt_ifp->if_addr->ifa_addr;
1544            info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
1545            if (rt->rt_ifp->if_flags & IFF_POINTOPOINT)
1546                info.rti_info[RTAX_BRD] = rt->rt_ifa->ifa_dstaddr;
1547        }