syzbot

uvm_fault(fffffd806b8ef378,20000000,0,2) at uvm_fault+0x112 sys/uvm/uvm_fault.c:600
kpageflttrap(ffff80002a148140,20000100) at kpageflttrap+0x2d0 sys/arch/amd64/amd64/trap.c:279
kerntrap(ffff80002a148140) at kerntrap+0x14a sys/arch/amd64/amd64/trap.c:332
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
copyout() at copyout+0x62
kern_sysctl(ffff80002a1484c4,5,20000100,ffff80002a1484f8,0,37,3a42a829f6046ef5) at kern_sysctl+0x320 sys/kern/kern_sysctl.c:500
sys_sysctl(ffff800034d9b708,ffff80002a148630,ffff80002a148580) at sys_sysctl+0x422
syscall(ffff80002a148630) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline]
syscall(ffff80002a148630) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x11c10897170, count: -23
ddb{0}> machine ddbcpu 1
Stopped at      proc_trampoline+0xc7:   movl    $0,%gs:0x680
proc_trampoline() at proc_trampoline+0xc7
end of kernel
end trace frame: 0x77c663c85ea0, count: 14
ddb{1}> trace
proc_trampoline() at proc_trampoline+0xc7
end of kernel
end trace frame: 0x77c663c85ea0, count: -1