syzbot


panic: ufsdirhash_lookup: bad offset in hash array (2)

Status: auto-obsoleted due to no activity on 2023/02/12 08:25
Reported-by: syzbot+f88b5f7b17db5d2ff46c@syzkaller.appspotmail.com
First crash: 738d, last: 738d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd panic: ufsdirhash_lookup: bad offset in hash array 1 920d 920d 0/3 auto-closed as invalid on 2022/08/14 03:42
openbsd panic: ufsdirhash_lookup: bad offset in hash array (3) C 79 9d17h 640d 0/3 upstream: reported C repro on 2023/02/20 12:28

Sample crash report:
panic: ufsdirhash_lookup: bad offset in hash array
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
* 43828   5688      0           0  0x4000000    0  syz-executor.6
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff8263a30f) at panic+0x161 sys/kern/subr_prf.c:198
ufsdirhash_lookup(fffffd80700502e0,ffff800021784000,1,fffffd807005038c,ffff8000217a8eb8,0) at ufsdirhash_lookup+0x8b8 sys/ufs/ufs/ufs_dirhash.c:343
ufs_lookup() at ufs_lookup+0xc15 sys/ufs/ufs/ufs_lookup.c:216
VOP_LOOKUP(fffffd806817b8d0,ffff8000217a9338,ffff8000217a9368) at VOP_LOOKUP+0x58 sys/kern/vfs_vops.c:85
vfs_lookup(ffff8000217a9308) at vfs_lookup+0x6cc sys/kern/vfs_lookup.c:560
namei(ffff8000217a9308) at namei+0x36a sys/kern/vfs_lookup.c:244
vn_open(ffff8000217a9308,1,0) at vn_open+0x105 sys/kern/vfs_vnops.c:140
doopenat(ffff800026642fc0,3,20000040,0,0,ffff8000217a94e0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1127
syscall(ffff8000217a9560) at syscall+0x446 sys/arch/amd64/amd64/trap.c:599
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xd71deb529b0, count: 4
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: ufsdirhash_lookup: bad offset in hash array
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff8263a30f) at panic+0x161 sys/kern/subr_prf.c:198
ufsdirhash_lookup(fffffd80700502e0,ffff800021784000,1,fffffd807005038c,ffff8000217a8eb8,0) at ufsdirhash_lookup+0x8b8 sys/ufs/ufs/ufs_dirhash.c:343
ufs_lookup() at ufs_lookup+0xc15 sys/ufs/ufs/ufs_lookup.c:216
VOP_LOOKUP(fffffd806817b8d0,ffff8000217a9338,ffff8000217a9368) at VOP_LOOKUP+0x58 sys/kern/vfs_vops.c:85
vfs_lookup(ffff8000217a9308) at vfs_lookup+0x6cc sys/kern/vfs_lookup.c:560
namei(ffff8000217a9308) at namei+0x36a sys/kern/vfs_lookup.c:244
vn_open(ffff8000217a9308,1,0) at vn_open+0x105 sys/kern/vfs_vnops.c:140
doopenat(ffff800026642fc0,3,20000040,0,0,ffff8000217a94e0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1127
syscall(ffff8000217a9560) at syscall+0x446 sys/arch/amd64/amd64/trap.c:599
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xd71deb529b0, count: -11
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff8000217a8ce0
rbx                                0
rdx               0xffff800000c35340
rcx                                0
rax               0xffff800026642fc0
r8                                 0
r9                0x8080808080808080
r10               0xeb9cae81ed015f23
r11               0xf9450f070d0ced19
r12                                0
r13               0xffff800000c2ed40
r14                                0
r15                              0x1
rip               0xffffffff81a514a8    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff8000217a8cd0
ss                              0x10
db_enter+0x18:  addq    $0x8,%rsp
ddb> show proc
PROC (syz-executor.6) pid=43828 stat=onproc
    flags process=0 proc=4000000<THREAD>
    pri=32, usrpri=83, nice=20
    forw=0xffffffffffffffff, list=0xffff800026642000,0xffff8000266437b0
    process=0xffff800021712bd0 user=0xffff8000217a4000, vmspace=0xfffffd80728bb110
    estcpu=36, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 42184  381841  56817      0  2           0                syz-executor.4
 60601  242918  18421      0  2           0                syz-executor.7
 16474  187994  15471      0  2           0                syz-executor.1
 16474  436117  15471      0  3   0x4000080  fsleep        syz-executor.1
 16474   36620  15471      0  3   0x4000080  fsleep        syz-executor.1
 16474  486366  15471      0  3   0x4000080  fsleep        syz-executor.1
  5688    9178  77888      0  2           0                syz-executor.6
* 5688   43828  77888      0  7   0x4000000                syz-executor.6
  5688  215702  77888      0  3   0x4000080  fsleep        syz-executor.6
   234   92701  30101      0  2           0                syz-executor.5
   234  297236  30101      0  3   0x4000080  fsleep        syz-executor.5
   234  378243  30101      0  3   0x4000080  fsleep        syz-executor.5
 31054  435451  59422      0  2         0x2                syz-executor.2
 30101  318236  59422      0  3        0x82  nanoslp       syz-executor.5
 13308  217578  59422      0  3        0x82  nanoslp       syz-executor.3
 11204  464181      0      0  3     0x14200  acct          acct
 26264  434301  59422      0  2         0x2                syz-executor.0
 15471  254037  59422      0  3        0x82  nanoslp       syz-executor.1
 18421  192899  59422      0  3        0x82  nanoslp       syz-executor.7
 15794  466390      1      0  3    0x100083  ttyin         getty
 77888   31758  59422      0  3        0x82  nanoslp       syz-executor.6
 58118  417291      0      0  3     0x14200  bored         sosplice
 26414  459099      0      0  3     0x14280  nfsidl        nfsio
 29046  141383      0      0  3     0x14280  nfsidl        nfsio
 25796  113424      0      0  3     0x14280  nfsidl        nfsio
 30562  124471      0      0  3     0x14280  nfsidl        nfsio
 70554  331887      0      0  3     0x14280  nfsidl        nfsio
 25943  451365      0      0  3     0x14280  nfsidl        nfsio
 54504  267172      0      0  3     0x14280  nfsidl        nfsio
 31759  174117      0      0  3     0x14280  nfsidl        nfsio
 34891  472023      0      0  3     0x14280  nfsidl        nfsio
 54407  213108      0      0  3     0x14280  nfsidl        nfsio
 78875  135734      0      0  3     0x14280  nfsidl        nfsio
 91345  137098      0      0  3     0x14280  nfsidl        nfsio
 20631  123125      0      0  3     0x14280  nfsidl        nfsio
 59874  284677      0      0  3     0x14280  nfsidl        nfsio
 78627  320173      0      0  3     0x14280  nfsidl        nfsio
 34903  378178      0      0  3     0x14280  nfsidl        nfsio
 66051  358328      0      0  3     0x14280  nfsidl        nfsio
 25847  116421      0      0  3     0x14280  nfsidl        nfsio
 97085  283230      0      0  3     0x14280  nfsidl        nfsio
 53436  142812      0      0  3     0x14280  nfsidl        nfsio
 56817  403463  59422      0  3        0x82  nanoslp       syz-executor.4
 59422   55010  26539      0  3        0x82  wait          syz-fuzzer
 59422  161383  26539      0  3   0x4000082  nanoslp       syz-fuzzer
 59422  171030  26539      0  3   0x4000082  wait          syz-fuzzer
 59422   77411  26539      0  3   0x4000082  thrsleep      syz-fuzzer
 59422   11034  26539      0  3   0x4000082  wait          syz-fuzzer
 59422  251115  26539      0  3   0x4000082  wait          syz-fuzzer
 59422  105322  26539      0  3   0x4000082  thrsleep      syz-fuzzer
 59422  119806  26539      0  3   0x4000082  wait          syz-fuzzer
 59422  204539  26539      0  3   0x4000082  thrsleep      syz-fuzzer
 59422   38746  26539      0  3   0x4000082  kqread        syz-fuzzer
 59422    4479  26539      0  3   0x4000082  wait          syz-fuzzer
 59422  117386  26539      0  3   0x4000082  thrsleep      syz-fuzzer
 59422  406830  26539      0  3   0x4000082  wait          syz-fuzzer
 59422  382371  26539      0  3   0x4000082  wait          syz-fuzzer
 26539  408107  74663      0  3    0x10008a  sigsusp       ksh
 74663  301710  18433      0  3        0x9a  kqread        sshd
 18433  118276      1      0  3        0x88  kqread        sshd
 25121  189703   4196     73  3   0x1100090  kqread        syslogd
  4196  352057      1      0  3    0x100082  netio         syslogd
  1289  479693      1      0  3    0x100080  kqread        resolvd
 61560  258414      0      0  3     0x14200  bored         smr
 87008   33018      0      0  2     0x14200                zerothread
 50893  504858      0      0  3     0x14200  aiodoned      aiodoned
 94536  298213      0      0  3     0x14200  syncer        update
 49412  460325      0      0  3     0x14200  cleaner       cleaner
 13458  342629      0      0  3     0x14200  reaper        reaper
 92653    7818      0      0  3     0x14200  pgdaemon      pagedaemon
 34073  250643      0      0  3     0x14200  bored         viomb
 73152   88019      0      0  3  0x40014200  acpi0         acpi0
 58583  193487      0      0  3     0x14200  bored         softnet
 50512   66125      0      0  3     0x14200  bored         softnet
  4342  293904      0      0  3     0x14200  bored         softnet
 40450  343236      0      0  3     0x14200  bored         softnet
 80021  404320      0      0  3     0x14200  bored         systqmp
 48884  259763      0      0  3     0x14200  bored         systq
 51539  499284      0      0  2  0x40014200                softclock
 30760  159563      0      0  3  0x40014200                idle0
     1    1862      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 10208   6422K    6927K  78643K     13602        0
            pcb    13     16K      18K  78643K       817        0
         rtable   178     16K      18K  78643K      1642        0
         ifaddr   115     25K      27K  78643K       861        0
         sysctl     3      1K       1K  78643K         3        0
       counters    25     17K      17K  78643K       353        0
       ioctlops     0      0K       4K  78643K      1522        0
            iov     0      0K      16K  78643K      1488        0
          mount     1      1K       1K  78643K         1        0
            log     0      0K       0K  78643K         4        0
         vnodes  1392     87K      88K  78643K      6577        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       5K  78643K        65        0
         VM map     2      0K       0K  78643K         2        0
            sem    15     10K      20K  78643K       313        0
        dirhash    75     13K      16K  78643K      5142        0
           ACPI  1697    195K     286K  78643K     12548        0
      file desc    15     53K      65K  78643K     11954        0
          sigio     0      0K       0K  78643K       117        0
           proc    56     51K      83K  78643K      2511        0
        subproc   104      6K       6K  78643K       390        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
    ip_moptions     0      0K       0K  78643K      1949        0
       in_multi    57      3K       6K  78643K      1649        0
    ether_multi     1      0K       0K  78643K        46        0
            mrt     1      0K       0K  78643K        19        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys   223    996K     996K  78643K       223        0
           exec     0      0K       1K  78643K      1950        0
            tdb     3      0K       0K  78643K         3        0
        pagedep     1      8K       8K  78643K         1        0
       inodedep     1     32K      32K  78643K         1        0
         newblk     1      0K       0K  78643K         1        0
        VM swap     8     62K      64K  78643K        10        0
       UVM amap   341    490K     502K  78643K     77181        0
       UVM aobj   131      4K       4K  78643K       134        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
    ip6_options     0      0K       0K  78643K       217        0
            NDP    13      0K       2K  78643K       222        0
           temp   132   4694K    5718K  78643K    113729        0
         kqueue     7     12K      26K  78643K       606        0
      SYN cache     2     16K      16K  78643K         2        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
rtpcb      120      308    0      307     2     1     1     2     0     8    0
rtentry    112      469    0      402     4     1     3     4     0     8    0
unpcb      144     8711    0     8705    80    79     1     8     0     8    0
syncache   296      331    0      331    21    21     0     1     0     8    0
tcpqe       32      109    0      109    11    11     0     1     0     8    0
tcpcb      776     6386    0     6380   149   140     9    17     0     8    8
arp         88       65    0       53     1     0     1     1     0     8    0
ipq         40       14    0       14     6     6     0     1     0     8    0
ipqe        40      253    0      253     6     6     0     1     0     8    0
inpcb      336    12776    0    12770   136   127     9    15     0     8    8
nd6         48      101    0       85     1     0     1     1     0     8    0
pkpcb       40       79    0       79     4     4     0     1     0     8    0
kcovpl      48       30    0       22     1     0     1     1     0     8    0
mppekey    1024      13    0       13     4     4     0     1     0     8    0
ppxss      1160     222    0      222    13    13     0     1     0     8    0
pppxif     1608     176    0      176    10    10     0     1     0     8    0
pfstscr     40      173    0      169     1     0     1     1     0     8    0
pfosfp      40        9    0        7     1     0     1     1     0     8    0
pfosfpen   112        9    0        6     1     0     1     1     0     8    0
pfanchor   1280     990  887      478    47     4    43    43     0     8    0
pfqueue    264        3    0        3     1     1     0     1     0     8    0
pfstitem    24       34    0       30     1     0     1     1     0     8    0
pfstkey    120      180    0      178     1     0     1     1     0     8    0
pfstate    352       90    0       88     1     0     1     1     0     8    0
rttmr      136        3    0        3     1     1     0     1     0     8    0
art_heap8  4096       5    0        4     5     4     1     2     0     8    0
art_heap4  256     2137    0     1867    41    20    21    29     0     8    0
art_table   32     2142    0     1871     4     0     4     4     0     8    0
art_node    16      468    0      411     1     0     1     1     0     8    0
sysvmsgpl   40       41    0       18     1     0     1     1     0     8    0
semapl     112      302    0      289     1     0     1     1     0     8    0
shmpl      112      131    0        3     4     0     4     4     0     8    0
dirhash    1024    1727    0     1689     6     0     6     6     0     8    0
dino2pl    256    19855    0    18344    95     0    95    95     0     8    0
ffsino     240    19855    0    18344    90     0    90    90     0     8    0
nchpl      144    39009    0    38524    63    41    22    63     0     8    0
rtmask      32        5    0        5     2     2     0     1     0     8    0
uvmvnodes   80     5926    0        0   121     0   121   121     0     8    0
vnodes     216     5926    0        0   330     0   330   330     0     8    0
namei      1024  146702    0   146699     4     2     2     2     0     8    1
vcpupl     2048      30    0        0     4     0     4     4     0     8    0
vmpool     536       41    0       11     3     1     2     2     0     8    0
kstatmem   264      308    0      282     3     0     3     3     0     8    0
scsiplug    72        3    0        3     1     1     0     1     0     8    0
scxspl     216   103072    0   103072    19    18     1     8     0     8    1
plimitpl   152      938    0      924     1     0     1     1     0     8    0
sigapl     424    12227    0    12165     8     0     8     8     0     8    0
futexpl     64   132723    0   132717     1     0     1     1     0     8    0
knotepl    120   121928    0   121863    32    27     5    10     0     8    0
kqueuepl   184     1421    0     1415    16    15     1     4     0     8    0
pipepl     288     2262    0     2233    60    55     5    11     0     8    2
fdescpl    432    12188    0    12165     4     0     4     4     0     8    0
filepl     120    95468    0    95242   127   114    13    17     0     8    5
lockfpl    104     3515    0     3514     9     8     1     2     0     8    0
lockfspl    48      744    0      743     1     0     1     1     0     8    0
sessionpl  144       46    0       31     1     0     1     1     0     8    0
pgrppl      48       63    0       48     1     0     1     1     0     8    0
ucredpl    104     6184    0     6177     1     0     1     1     0     8    0
zombiepl   144    12166    0    12165     2     1     1     1     0     8    0
processpl  1000   12227    0    12165     9     0     9     9     0     8    0
procpl     672    30136    0    30054    17     9     8     9     0     8    0
sosppl     168      246    0      246    15    14     1     1     0     8    1
sockpl     456    21885    0    21872   403   393    10    28     0     8    8
mcl64k     65536    460    0      460    16    15     1     1     0     8    1
mcl16k     16384    100    0      100    17    16     1     1     0     8    1
mcl12k     12288    516    0      516    17    16     1     1     0     8    1
mcl9k      9216      90    0       90    25    24     1     1     0     8    1
mcl8k      8192     708    0      708    12    11     1     1     0     8    1
mcl4k      4096    2204    0     2204     8     7     1     1     0     8    1
mcl2k2     2112      69    0       69    26    26     0     1     0     8    0
mcl2k      2048   93374    0    93328    55    47     8    31     0     8    1
mtagpl      96      109    0      109     4     4     0     3     0     8    0
mbufpl     256   275554    0   275455   343   327    16   159     0     8    0
bufpl      288    21931    0    15529   458     0   458   458     0     8    0
anonpl      24  2216416    0  2200441   200    89   111   126     0   188    4
amapchunkpl 152  240382    0   239711    94    65    29    42     0   158    0
amappl16   200    18943    0    18418   108    80    28    40     0     8    0
amappl15   192        5    0        5     1     1     0     1     0     8    0
amappl14   184      238    0      227     2     1     1     2     0     8    0
amappl13   176       11    0       10     1     0     1     1     0     8    0
amappl12   168      662    0      658     1     0     1     1     0     8    0
amappl11   160       41    0       37     1     0     1     1     0     8    0
amappl10   152       54    0       44     1     0     1     1     0     8    0
amappl9    144      997    0      995     1     0     1     1     0     8    0
amappl8    136      391    0      305     3     0     3     3     0     8    0
amappl7    128       68    0       51     1     0     1     1     0     8    0
amappl6    120      568    0      555     2     1     1     2     0     8    0
amappl5    112      191    0      186     1     0     1     1     0     8    0
amappl4    104     1004    0      981     2     1     1     2     0     8    0
amappl3     96    34376    0    34339     2     0     2     2     0     8    0
amappl2     88    12937    0    12888     3     1     2     3     0     8    0
amappl1     80   271520    0   270974    22     8    14    21     0     8    0
amappl      88    76530    0    76349     5     0     5     5     0    92    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma1024    1024       1    0        0     1     0     1     1     0     8    0
dma256     256        6    0        6     1     1     0     1     0     8    0
dma128     128      253    0      253     1     1     0     1     0     8    0
dma64       64        6    0        6     1     1     0     1     0     8    0
dma32       32        7    0        7     1     1     0     1     0     8    0
dma16       16       18    0       17     1     0     1     1     0     8    0
aobjpl      72      133    0        3     3     0     3     3     0     8    0
uaddrrnd    24    12229    0    12176     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24    12229    0    12176     1     0     1     1     0     8    0
vmmpekpl   168    82442    0    82379     4     0     4     4     0     8    0
vmmpepl    168  1085364    0  1083106   234   119   115   133     0   357    0
vmsppl     272    12228    0    12176     4     0     4     4     0     8    0
rwobjpl     24   279503    0   271988    50     3    47    48     0     8    0
pdppl      4096   24464    0    24382   557   469    88    88     0     8    6
pvpl        32  4247332    0  4227079   360   170   190   232     0   265   15
pmappl     216    12228    0    12176     5     1     4     4     0     8    0
extentpl    40       56    0       38     1     0     1     1     0     8    0
phpool     112     1918    0     1106    29     5    24    27     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff8263a30f) at panic+0x161 sys/kern/subr_prf.c:198
ufsdirhash_lookup(fffffd80700502e0,ffff800021784000,1,fffffd807005038c,ffff8000217a8eb8,0) at ufsdirhash_lookup+0x8b8 sys/ufs/ufs/ufs_dirhash.c:343
ufs_lookup() at ufs_lookup+0xc15 sys/ufs/ufs/ufs_lookup.c:216
VOP_LOOKUP(fffffd806817b8d0,ffff8000217a9338,ffff8000217a9368) at VOP_LOOKUP+0x58 sys/kern/vfs_vops.c:85
vfs_lookup(ffff8000217a9308) at vfs_lookup+0x6cc sys/kern/vfs_lookup.c:560
namei(ffff8000217a9308) at namei+0x36a sys/kern/vfs_lookup.c:244
vn_open(ffff8000217a9308,1,0) at vn_open+0x105 sys/kern/vfs_vnops.c:140
doopenat(ffff800026642fc0,3,20000040,0,0,ffff8000217a94e0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1127
syscall(ffff8000217a9560) at syscall+0x446 sys/arch/amd64/amd64/trap.c:599
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xd71deb529b0, count: -11
ddb> machine ddbcpu 1
No such command
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff8263a30f) at panic+0x161 sys/kern/subr_prf.c:198
ufsdirhash_lookup(fffffd80700502e0,ffff800021784000,1,fffffd807005038c,ffff8000217a8eb8,0) at ufsdirhash_lookup+0x8b8 sys/ufs/ufs/ufs_dirhash.c:343
ufs_lookup() at ufs_lookup+0xc15 sys/ufs/ufs/ufs_lookup.c:216
VOP_LOOKUP(fffffd806817b8d0,ffff8000217a9338,ffff8000217a9368) at VOP_LOOKUP+0x58 sys/kern/vfs_vops.c:85
vfs_lookup(ffff8000217a9308) at vfs_lookup+0x6cc sys/kern/vfs_lookup.c:560
namei(ffff8000217a9308) at namei+0x36a sys/kern/vfs_lookup.c:244
vn_open(ffff8000217a9308,1,0) at vn_open+0x105 sys/kern/vfs_vnops.c:140
doopenat(ffff800026642fc0,3,20000040,0,0,ffff8000217a94e0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1127
syscall(ffff8000217a9560) at syscall+0x446 sys/arch/amd64/amd64/trap.c:599
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xd71deb529b0, count: -11

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/11/14 08:25 openbsd 67a10ba2366d 7ba4d859 .config console log report ci-openbsd-main panic: ufsdirhash_lookup: bad offset in hash array
* Struck through repros no longer work on HEAD.