syzbot

uvm_fault(0xffffffff83aee2d0, 0xffff8000259b2004, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ufs_readdir+0x26e:      movzwl  0x4(%r14),%ebx
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*215896  78633      0         0x2          0    0  syz-executor
ufs_readdir(ffff80002a7d3030) at ufs_readdir+0x26e sys/ufs/ufs/ufs_vnops.c:1397
VOP_READDIR(fffffd8071b59db0,ffff80002a7d30b8,fffffd8007ffd8f0,ffff80002a7d30fc) at VOP_READDIR+0x125 sys/kern/vfs_vops.c:453
sys_getdents(ffff80002a7787d8,ffff80002a7d3240,ffff80002a7d3190) at sys_getdents+0x2dd sys/kern/vfs_syscalls.c:3220
syscall(ffff80002a7d3240) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7d3240) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71dfefade850, count: 10
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> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
*cpu0: uvm_fault(0xffffffff83aee2d0, 0xffff8000259b2004, 0, 1) -> d
ddb> trace
ufs_readdir(ffff80002a7d3030) at ufs_readdir+0x26e sys/ufs/ufs/ufs_vnops.c:1397
VOP_READDIR(fffffd8071b59db0,ffff80002a7d30b8,fffffd8007ffd8f0,ffff80002a7d30fc) at VOP_READDIR+0x125 sys/kern/vfs_vops.c:453
sys_getdents(ffff80002a7787d8,ffff80002a7d3240,ffff80002a7d3190) at sys_getdents+0x2dd sys/kern/vfs_syscalls.c:3220
syscall(ffff80002a7d3240) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a7d3240) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71dfefade850, count: -5
ddb> show registers
rdi                            0x200
rsi                            0x800
rbp               0xffff80002a7d3020
rbx                            0x200
rdx                                0
rcx               0xfffffd8064088b10
rax               0xffff8000259b2200
r8                0xffffffffffffffff
r9                               0x3
r10               0x47262cb52c31f460
r11               0x3ce121a727aab84f
r12                                0
r13               0xffff80002a7d30b8
r14               0xffff8000259b2000
r15               0xffff8000259b2008
rip               0xffffffff81d3375e    ufs_readdir+0x26e
cs                               0x8
rflags                       0x10283    __ALIGN_SIZE+0xf283
rsp               0xffff80002a7d2e70
ss                              0x10
ufs_readdir+0x26e:      movzwl  0x4(%r14),%ebx
ddb> show proc
PROC (syz-executor) tid=215896 pid=78633 tcnt=1 stat=onproc
    flags process=2<EXEC> proc=0
    runpri=32, usrpri=50, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a778d08,0xffff80002a778a80
    process=0xffff80002a79c910 user=0xffff80002a7ce000, vmspace=0xfffffd807ec65170
    estcpu=36, cpticks=6, pctcpu=0.0, user=0, sys=6, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 31242   36152  11005      0  2           0                syz-executor
 31242  520171  11005      0  3   0x4000080  fsleep        syz-executor
 31242  173941  11005      0  2   0x4000000                syz-executor
 86635   42934  97084      0  2           0                syz-executor
 86635  161366  97084      0  3   0x4000080  fsleep        syz-executor
 52847    9539  41067      0  2        0x10                syz-executor
 52847  194893  41067      0  3   0x4000090  fsleep        syz-executor
 52847  354791  41067      0  3   0x4000090  fsleep        syz-executor
 41067  137662   3944      0  3        0x82  nanoslp       syz-executor
 81604  138445      1      0  3        0x80  nanoslp       init
 48897  291075      0      0  3     0x14280  nfsidl        nfsio
 60642   28040      0      0  3     0x14280  nfsidl        nfsio
  8787  390777      0      0  3     0x14280  nfsidl        nfsio
 34922   45853      0      0  3     0x14280  nfsidl        nfsio
  6818  352228      0      0  3     0x14280  nfsidl        nfsio
 76112  359183      0      0  3     0x14280  nfsidl        nfsio
 74596  333560      0      0  3     0x14280  nfsidl        nfsio
 74351  374458      0      0  3     0x14280  nfsidl        nfsio
 94936  445460      0      0  3     0x14280  nfsidl        nfsio
   832  187590      0      0  3     0x14280  nfsidl        nfsio
 15742  203505      0      0  3     0x14280  nfsidl        nfsio
 78077  274327      0      0  3     0x14280  nfsidl        nfsio
 11874   71680      0      0  3     0x14280  nfsidl        nfsio
 12690  360104      0      0  3     0x14280  nfsidl        nfsio
 46557  291841      0      0  3     0x14280  nfsidl        nfsio
 74641  452775      0      0  3     0x14280  nfsidl        nfsio
 28320   97396      0      0  3     0x14280  nfsidl        nfsio
 90282  201057      0      0  3     0x14280  nfsidl        nfsio
 62219   10550      0      0  3     0x14280  nfsidl        nfsio
 43942  363600      0      0  3     0x14280  nfsidl        nfsio
 24590   79757   3944      0  2       0xc82                syz-executor
 97084  227798   3944      0  3        0x82  nanoslp       syz-executor
 11005  449611   3944      0  3        0x82  nanoslp       syz-executor
 19723  437251   3944      0  3        0x82  wait          syz-executor
*78633  215896   3944      0  7         0x2                syz-executor
  3944  294295      1      0  2  0x10000002                syz-executor
 75008  103776      0      0  3     0x14200  bored         smr
 33630  516829      0      0  2     0x14200                zerothread
 38655  433349      0      0  3     0x14200  aiodoned      aiodoned
  1248    9387      0      0  3     0x14200  syncer        update
 15155  137611      0      0  3     0x14200  cleaner       cleaner
 94102  489672      0      0  3     0x14200  reaper        reaper
 10575  499950      0      0  3     0x14200  pgdaemon      pagedaemon
 17146  122605      0      0  3     0x14200  bored         viomb
 96824  509484      0      0  3  0x40014200  acpi0         acpi0
  3627  209193      0      0  2     0x14200                softnet0
 30539  490788      0      0  3     0x14200  bored         systqmp
 64128  101059      0      0  3     0x14200  bored         systq
 64417   94545      0      0  3  0x40014200  tmoslp        softclock
 41293  244705      0      0  3  0x40014200                idle0
     1  386527      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb> show all locks
No such command
ddb> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11024  12090K   12422K 166960K     13538        0
            pcb    17     15K      16K 166960K       176        0
         rtable   155      6K      10K 166960K       516        0
             pf    31     13K      20K 166960K       185        0
         ifaddr    26      4K       7K 166960K        73        0
        ifgroup    42      1K       2K 166960K       112        0
         sysctl     4      1K       9K 166960K        11        0
       counters    31     17K      18K 166960K        64        0
       ioctlops     0      0K       4K 166960K       328        0
            iov     0      0K      20K 166960K       107        0
          mount     1      1K       1K 166960K         1        0
            log     1      0K       0K 166960K         5        0
         vnodes  1385     87K      87K 166960K      2259        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       9K 166960K        21        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K       108        0
        dirhash    12      2K       2K 166960K        33        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    13     49K     244K 166960K       951        0
          sigio     0      0K       0K 166960K       138        0
           proc    11     17K     108K 166960K       613        0
        subproc    63      3K       4K 166960K        81        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     2      0K       0K 166960K        97        0
       in_multi    53      3K       7K 166960K       134        0
    ether_multi     1      0K       0K 166960K         5        0
            mrt     1      0K       0K 166960K        23        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    79    360K     360K 166960K        79        0
           exec     0      0K       1K 166960K       817        0
   fusefs mount     1     32K      32K 166960K         1        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   108     69K     167K 166960K      9748        0
       UVM aobj    23      4K       4K 166960K        27        0
     pinsyscall    15     30K      96K 166960K      2066        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        27        0
            NDP     9      0K       2K 166960K        49        0
           temp    58   9112K    9183K 166960K     38105        0
         kqueue     2      4K      28K 166960K       188        0
      SYN cache     2     16K      16K 166960K         2        0
ddb>