Fatal trap 9: general protection fault in unp_gc

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 3d80c629 netmap: update unit tests
git tree: freebsd
console output: https://syzkaller.appspot.com/x/log.txt?x=11b6d6ef200000
dashboard link: https://syzkaller.appspot.com/bug?extid=d2fc343bf8b2872586cb

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d2fc34...@syzkaller.appspotmail.com

Fatal trap 9: general protection fault while in kernel mode
cpuid = 0; apic id = 00
instruction pointer = 0x20:0xffffffff81164355
stack pointer = 0x28:0xfffffe0016a9f920
frame pointer = 0x28:0xfffffe0016a9f9c0
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 = 0 (thread taskq)
trap number = 9
panic: general protection fault
cpuid = 0
time = 339
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame
0xfffffe0016a9f5f0
vpanic() at vpanic+0x1e0/frame 0xfffffe0016a9f650
panic() at panic+0x43/frame 0xfffffe0016a9f6b0
trap_fatal() at trap_fatal+0x4c6/frame 0xfffffe0016a9f730
trap() at trap+0xba/frame 0xfffffe0016a9f850
calltrap() at calltrap+0x8/frame 0xfffffe0016a9f850
--- trap 0x9, rip = 0xffffffff81164355, rsp = 0xfffffe0016a9f920, rbp =
0xfffffe0016a9f9c0 ---
unp_gc() at unp_gc+0x2b5/frame 0xfffffe0016a9f9c0
taskqueue_run_locked() at taskqueue_run_locked+0x145/frame
0xfffffe0016a9fa20
taskqueue_thread_loop() at taskqueue_thread_loop+0xdd/frame
0xfffffe0016a9fa60
fork_exit() at fork_exit+0xb0/frame 0xfffffe0016a9fab0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0016a9fab0
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 0 tid 100008 ]
Stopped at kdb_enter+0x6a: movq $0,kdb_why


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.