syzbot

Fatal trap 9: general protection fault while in kernel mode
cpuid = 0; apic id = 00
instruction pointer	= 0x20:0xffffffff81158609
stack pointer	        = 0x28:0xfffffe001a1010e0
frame pointer	        = 0x28:0xfffffe001a1010f0
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		= 1 (kernel)
trap number		= 9
panic: general protection fault
cpuid = 0
time = 1
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe001a100d80
vpanic() at vpanic+0x1ce/frame 0xfffffe001a100df0
panic() at panic+0x43/frame 0xfffffe001a100e50
trap_fatal() at trap_fatal+0x4cc/frame 0xfffffe001a100ed0
trap() at trap+0xe4/frame 0xfffffe001a101010
calltrap() at calltrap+0x8/frame 0xfffffe001a101010
--- trap 0x9, rip = 0xffffffff81158609, rsp = 0xfffffe001a1010e0, rbp = 0xfffffe001a1010f0 ---
biotrack_buf() at biotrack_buf+0x19/frame 0xfffffe001a1010f0
g_io_deliver() at g_io_deliver+0x39/frame 0xfffffe001a101150
g_io_request() at g_io_request+0x57a/frame 0xfffffe001a1011a0
g_part_start() at g_part_start+0x223/frame 0xfffffe001a101240
g_io_request() at g_io_request+0x57a/frame 0xfffffe001a101290
g_io_request() at g_io_request+0x57a/frame 0xfffffe001a1012e0
g_io_getattr() at g_io_getattr+0x83/frame 0xfffffe001a101320
ffs_mount() at ffs_mount+0x2412/frame 0xfffffe001a1014e0
vfs_domount() at vfs_domount+0xc26/frame 0xfffffe001a101720
vfs_donmount() at vfs_donmount+0xc87/frame 0xfffffe001a1017d0
kernel_mount() at kernel_mount+0x92/frame 0xfffffe001a101830
parse_mount() at parse_mount+0x8ee/frame 0xfffffe001a101990
vfs_mountroot() at vfs_mountroot+0x5f4/frame 0xfffffe001a101b00
start_init() at start_init+0x2c/frame 0xfffffe001a101ba0
fork_exit() at fork_exit+0xac/frame 0xfffffe001a101bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe001a101bf0
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 1 tid 100002 ]
Stopped at      kdb_enter+0x67: movq    $0,0x14663f6(%rip)
db>