syzbot

uvm_fault(0xfffffd800f49fd78, 0x98, 0, 1) -> e
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff830d17e8 cs 8 rflags 10246 cr2 98 cpl 0 rsp ffff80002a25d910
gsbase 0xffff8000299bdff0  kgsbase 0x0
panic: trap type 6, code=0, pc=ffffffff830d17e8
Starting stack trace...
panic(ffffffff8347cd48) at panic+0x1d0 sys/kern/subr_prf.c:229
kerntrap(ffff80002a25d860) at kerntrap+0x30b
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
dovutimens(ffff8000ffffc538,fffffd8068b316f0,ffff80002a25da40) at dovutimens+0x368 sys/kern/vfs_syscalls.c:2771
sys_futimes(ffff8000ffffc538,ffff80002a25db90,ffff80002a25dae0) at sys_futimes+0x208 sys/kern/vfs_syscalls.c:2813
syscall(ffff80002a25db90) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a25db90) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7415c395ca0, count: 250
End of stack trace.
WARNING: SPL NOT LOWERED ON SYSCALL 74 696934400 EXIT 0 4
Stopped at      savectx+0xae:   movl    $0,%gs:0x688
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
 358361  99075      0           0          0    0  syz-executor
*503127  89608      0           0          0    1  syz-executor
savectx() at savectx+0xae
end of kernel
end trace frame: 0x7d15ba700f30, count: 14
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports.  Insufficient info makes it difficult to find and fix bugs.
ddb{1}> 
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: uvm_fault(0xfffffd800f49fd78, 0x98, 0, 1) -> e
ddb{1}> trace
savectx() at savectx+0xae
end of kernel
end trace frame: 0x7d15ba700f30, count: -1
ddb{1}>