syzbot


assert "dtlookup(unit) == NULL" failed in dt_dev.c

Status: auto-closed as invalid on 2022/04/23 15:45
Reported-by: syzbot+fe309cdf0902ab141573@syzkaller.appspotmail.com
First crash: 1033d, last: 1033d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd assert "dtlookup(unit) == NULL" failed in dt_dev.c (2) 1 479d 479d 0/3 auto-obsoleted due to no activity on 2023/10/29 04:48
openbsd assert "dtlookup(unit) == NULL" failed in dt_dev.c (3) 1 325d 325d 3/3 fixed on 2024/01/03 04:06

Sample crash report:
panic: kernel diagnostic assertion "dtlookup(unit) == NULL" failed: file "/syzkaller/managers/main/kernel/sys/dev/dt/dt_dev.c", line 158
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
* 13682  26248      0           0  0x4000000    0  syz-executor.0
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440
panic(ffffffff82549a0b) at panic+0x161 sys/kern/subr_prf.c:202
__assert(ffffffff825b952b,ffffffff825dcd39,9e,ffffffff82566db3) at __assert+0x25 sys/kern/subr_prf.c:161
dtopen(31e6e,1,2000,ffff800026539268) at dtopen+0x1c4 sys/dev/dt/dt_dev.c:158
spec_open_clone(ffff80002ea1d088) at spec_open_clone+0x204
spec_open(ffff80002ea1d088) at spec_open+0x3f5 sys/kern/spec_vnops.c:155
VOP_OPEN(fffffd80693f0860,1,fffffd807f7d88a0,ffff800026539268) at VOP_OPEN+0x6c sys/kern/vfs_vops.c:138
vn_open(ffff80002ea1d2d8,1,0) at vn_open+0x467 sys/kern/vfs_vnops.c:183
doopenat(ffff800026539268,ffffff9c,20000000,0,0,ffff80002ea1d4c0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1128
syscall(ffff80002ea1d530) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3ed9365a910, 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: kernel diagnostic assertion "dtlookup(unit) == NULL" failed: file "/syzkaller/managers/main/kernel/sys/dev/dt/dt_dev.c", line 158
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440
panic(ffffffff82549a0b) at panic+0x161 sys/kern/subr_prf.c:202
__assert(ffffffff825b952b,ffffffff825dcd39,9e,ffffffff82566db3) at __assert+0x25 sys/kern/subr_prf.c:161
dtopen(31e6e,1,2000,ffff800026539268) at dtopen+0x1c4 sys/dev/dt/dt_dev.c:158
spec_open_clone(ffff80002ea1d088) at spec_open_clone+0x204
spec_open(ffff80002ea1d088) at spec_open+0x3f5 sys/kern/spec_vnops.c:155
VOP_OPEN(fffffd80693f0860,1,fffffd807f7d88a0,ffff800026539268) at VOP_OPEN+0x6c sys/kern/vfs_vops.c:138
vn_open(ffff80002ea1d2d8,1,0) at vn_open+0x467 sys/kern/vfs_vnops.c:183
doopenat(ffff800026539268,ffffff9c,20000000,0,0,ffff80002ea1d4c0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1128
syscall(ffff80002ea1d530) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3ed9365a910, count: -11
ddb> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80002ea1ce60
rbx                                0
rdx               0xffff800000d25140
rcx                                0
rax               0xffff800026539268
r8                 0x101010101010101
r9                0x8080808080808080
r10               0x3d6f56cc364090c8
r11               0xd075044b18fb4d16
r12                                0
r13               0xffff800000bc4f00
r14                                0
r15                              0x1
rip               0xffffffff81d364f8    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff80002ea1ce50
ss                                 0
db_enter+0x18:  addq    $0x8,%rsp
ddb> show proc
PROC (syz-executor.0) pid=13682 stat=onproc
    flags process=0 proc=4000000<THREAD>
    pri=84, usrpri=84, nice=20
    forw=0xffffffffffffffff, list=0xffff8000265382a8,0xffff800026539a58
    process=0xffff8000230fdb80 user=0xffff80002ea18000, vmspace=0xfffffd805e248340
    estcpu=34, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 63487  523854  68970      0  2           0                syz-executor.6
 63487  347302  68970      0  2   0x4000000                syz-executor.6
 54403  402420  32087      0  2           0                syz-executor.1
 54403  300951  32087      0  2   0x4000000                syz-executor.1
 54403  181245  32087      0  2   0x4000000                syz-executor.1
 19869   41957  18806      0  3           0  futex         syz-executor.7
 19869   32263  18806      0  3   0x4000080  fsleep        syz-executor.7
 19869  482721  18806      0  2   0x4000000                syz-executor.7
 19869  223187  18806      0  2   0x4000000                syz-executor.7
 12860  254470  21074      0  4     0x82004                syz-executor.3
 12860   64561  21074      0  2   0x4002004                syz-executor.3
 12860  214060  21074      0  4   0x4082004                syz-executor.3
 12860  209792  21074      0  4   0x4082004                syz-executor.3
 12860  195613  21074      0  4   0x4082004                syz-executor.3
 26248    9672  13552      0  2           0                syz-executor.0
 26248  327413  13552      0  3   0x4000080  dtread        syz-executor.0
 26248  392887  13552      0  2   0x4000000                syz-executor.0
*26248   13682  13552      0  7   0x4000000                syz-executor.0
 40160  296868      1      0  3    0x100083  ttyin         getty
 45251  367339  53036      0  2         0x2                syz-executor.4
 68970  458969  53036      0  3        0x82  nanoslp       syz-executor.6
 32087   97968  53036      0  3        0x82  nanoslp       syz-executor.1
 88424  506099  53036      0  2         0x2                syz-executor.5
 18806  316891  53036      0  3        0x82  nanoslp       syz-executor.7
 21074  104484  53036      0  3        0x82  nanoslp       syz-executor.3
 13552  372407  53036      0  3        0x82  nanoslp       syz-executor.0
 92817  390577      0      0  3     0x14280  nfsidl        nfsio
 33194  496058      0      0  3     0x14280  nfsidl        nfsio
 80930  238672      0      0  3     0x14280  nfsidl        nfsio
 74288   15873      0      0  3     0x14280  nfsidl        nfsio
 90815  339721      0      0  3     0x14280  nfsidl        nfsio
 23836  376748      0      0  3     0x14280  nfsidl        nfsio
 63275  148005  53036      0  2         0x2                syz-executor.2
 64870  214804      0      0  3     0x14200  bored         sosplice
 71419  483610      0      0  3     0x14200  acct          acct
 53036  366724  74252      0  3        0x82  thrsleep      syz-fuzzer
 53036  267714  74252      0  3   0x4000082  thrsleep      syz-fuzzer
 53036  406097  74252      0  3   0x4000082  kqread        syz-fuzzer
 53036   20236  74252      0  3   0x4000082  thrsleep      syz-fuzzer
 53036    1089  74252      0  3   0x4000082  thrsleep      syz-fuzzer
 53036  106490  74252      0  3   0x4000082  thrsleep      syz-fuzzer
 53036  428185  74252      0  3   0x4000082  thrsleep      syz-fuzzer
 53036  124176  74252      0  3   0x4000082  thrsleep      syz-fuzzer
 53036  468703  74252      0  3   0x4000082  thrsleep      syz-fuzzer
 74252  483286  86578      0  3    0x10008a  sigsusp       ksh
 86578  119598  79829      0  3        0x9a  poll          sshd
 79829  303998      1      0  3        0x88  poll          sshd
 57378  117308  57279     73  3    0x100090  kqread        syslogd
 57279  357467      1      0  3    0x100082  netio         syslogd
 24179   21690      1      0  3    0x100080  kqread        resolvd
 14689  200818  40297     77  3    0x100092  kqread        dhcpleased
 43661  189395  40297     77  3    0x100092  kqread        dhcpleased
 40297  211824      1      0  3        0x80  kqread        dhcpleased
 80112  197645      0      0  3     0x14200  bored         smr
 22324   67166      0      0  2     0x14200                zerothread
 16620  302488      0      0  3     0x14200  aiodoned      aiodoned
 78726    1911      0      0  3     0x14200  syncer        update
 35564  329859      0      0  3     0x14200  cleaner       cleaner
 96714  299961      0      0  3     0x14200  reaper        reaper
 32528   74619      0      0  3     0x14200  pgdaemon      pagedaemon
 95955  101266      0      0  3     0x14200  bored         viomb
 91022  177228      0      0  3  0x40014200  acpi0         acpi0
 52135  407109      0      0  2     0x14200                softnet
 19579  259172      0      0  3     0x14200  bored         systqmp
 46329  514407      0      0  3     0x14200  bored         systq
 97385   69959      0      0  2  0x40014200                softclock
 98819  244302      0      0  3  0x40014200                idle0
     1  379835      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 10204   6480K    7589K  78643K     41002        0
            pcb    13     16K      18K  78643K      1502        0
         rtable   177     24K      25K  78643K      4098        0
         ifaddr    95     20K      23K  78643K      1355        0
         sysctl     3      1K       1K  78643K         7        0
       counters    28     17K      17K  78643K       139        0
       ioctlops     0      0K       8K  78643K      1886        0
            iov     0      0K      28K  78643K      2010        0
          mount     1      1K       1K  78643K         1        0
            log     0      0K       0K  78643K         4        0
         vnodes  1549     97K      97K  78643K     10779        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       9K  78643K        57        0
         VM map     2      0K       0K  78643K         2        0
            sem    24      1K       1K  78643K       299        0
        dirhash     6      1K       2K  78643K        12        0
           ACPI  1697    195K     286K  78643K     12598        0
      file desc    16     57K      69K  78643K      9211        0
          sigio     0      0K       0K  78643K       112        0
           proc    58     55K      71K  78643K      2476        0
        subproc   104      6K       7K  78643K       899        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
    ip_moptions     0      0K       0K  78643K       564        0
       in_multi    48      3K       6K  78643K       980        0
    ether_multi     1      0K       0K  78643K       109        0
            mrt     1      0K       0K  78643K        72        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys   199    890K     890K  78643K       199        0
           exec     1      0K       2K  78643K      3842        0
     pfkey data     0      0K       1K  78643K         4        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     7     26K      26K  78643K         7        0
       UVM amap   469    783K    1357K  78643K    113430        0
       UVM aobj   131      8K       8K  78643K       131        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
    ip6_options     0      0K       0K  78643K       409        0
            NDP    14      0K       2K  78643K       265        0
           temp   147   4709K    4783K  78643K     95213        0
         kqueue    10     14K      24K  78643K       353        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     1945    0     1942    15    14     1     3     0     8    0
rtentry    112      867    0      816     4     0     4     4     0     8    0
unpcb      136     5780    0     5763    54    53     1     9     0     8    0
syncache   296       54    0       54    14    14     0     1     0     8    0
tcpqe       32       14    0       14     5     5     0     1     0     8    0
tcpcb      736     3135    0     3131   114   113     1    19     0     8    0
arp         88      145    0      136     1     0     1     1     0     8    0
ipq         40       94    0       94     9     9     0     1     0     8    0
ipqe        40     3769    0     3769     9     9     0     1     0     8    0
inpcb      304     7926    0     7919   124   121     3    14     0     8    2
rttmr       72       29    0       28    10     9     1     1     0     8    0
ip6q        72        5    0        5     2     2     0     1     0     8    0
ip6af       40        8    0        8     1     1     0     1     0     8    0
nd6         48      223    0      212     1     0     1     1     0     8    0
pkpcb       40      121    0      121     7     7     0     1     0     8    0
kcovpl      48       69    0       61     1     0     1     1     0     8    0
ppxss      1152      14    0       14     4     4     0     1     0     8    0
pfstscr     40       70    0       68     1     0     1     1     0     8    0
pfosfp      40        9    0        7     1     0     1     1     0     8    0
pfosfpen   112        9    0        0     1     0     1     1     0     8    0
pfrktable  1344     662    0      640     6     4     2     3     0     8    0
pftag       88       41    0       28     2     1     1     1     0     8    0
pfstitem    24      114    0      110     1     0     1     1     0     8    0
pfstkey    112      268    0      264     1     0     1     1     0     8    0
pfstate    320      134    0      132     1     0     1     1     0     8    0
pfrule     1360     428    0      234    20     3    17    17     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256     3550    0     3286    47    26    21    30     0     8    0
art_table   32     3551    0     3286     4     0     4     4     0     8    0
art_node    16      856    0      812     1     0     1     1     0     8    0
sysvmsgpl   40       11    0        8     2     1     1     1     0     8    0
semupl     112        4    0        4     2     2     0     1     0     8    0
semapl     112      295    0      273     1     0     1     1     0     8    0
shmpl      112      128    0        0     4     0     4     4     0     8    0
dirhash    1024      17    0       13     3     1     2     3     0     8    0
dino2pl    256    13449    0    11990    92     0    92    92     0     8    0
ffsino     240    13449    0    11990    88     1    87    87     0     8    0
nchpl      144    26068    0    24449    63     1    62    63     0     8    0
uvmvnodes   80     5926    0        0   121     0   121   121     0     8    0
vnodes     224     5926    0        0   349     0   349   349     0     8    0
namei      1024   94607    0    94603     6     5     1     2     0     8    0
vcpupl     1984     187    0        0    24     0    24    24     0     8    0
vmpool     528      208    0       21    13     0    13    13     0     8    0
pfiaddrpl  120      273    0      208     2     0     2     2     0     8    0
scsiplug    72       11    0       11     3     3     0     1     0     8    0
scxspl     216    79631    0    79631    26    25     1     8     0     8    1
plimitpl   152     1312    0     1298     1     0     1     1     0     8    0
sigapl     424     9386    0     9338     6     0     6     6     0     8    0
futexpl     64    86701    0    86699     6     5     1     1     0     8    0
knotepl    112     3334    0     3260     4     1     3     4     0     8    0
kqueuepl   184     1773    0     1767    24    23     1     4     0     8    0
pipepl     304     1562    0     1534    28    25     3     8     0     8    0
fdescpl    432     9365    0     9338    12     8     4     4     0     8    0
filepl     120    62302    0    62057    85    75    10    17     0     8    0
lockfpl    104     4750    0     4745     9     8     1     2     0     8    0
lockfspl    48     1421    0     1416     1     0     1     1     0     8    0
sessionpl  144       88    0       72     1     0     1     1     0     8    0
pgrppl      48      177    0      161     1     0     1     1     0     8    0
ucredpl     96     7136    0     7124     1     0     1     1     0     8    0
zombiepl   144    12019    0    12019     3     2     1     1     0     8    1
processpl  1000    9386    0     9338     7     0     7     7     0     8    0
procpl     672    25073    0    25004    20    13     7     8     0     8    0
sosppl     168       60    0       60     8     8     0     1     0     8    0
sockpl     448    15855    0    15828   309   304     5    30     0     8    2
mcl64k     65536    424    0      424    33    32     1     1     0     8    1
mcl16k     16384     92    0       92    22    22     0     1     0     8    0
mcl12k     12288    260    0      260    24    24     0     1     0     8    0
mcl9k      9216     107    0      107    26    25     1     1     0     8    1
mcl8k      8192     650    0      650    40    39     1     1     0     8    1
mcl4k      4096     903    0      903    26    25     1     1     0     8    1
mcl2k2     2112      57    0       57    30    30     0     1     0     8    0
mcl2k      2048   93815    0    93739    40    27    13    30     0     8    0
mtagpl      96     7532    0     6188    56    22    34    34     0     8    0
mbufpl     256   598941    0   596061   414   232   182   184     0     8    0
bufpl      288    19373    0    12965   459     0   459   459     0     8    0
anonpl      24  2665635    0  2643419   327   167   160   169     0   188   12
amapchunkpl 152  333016    0   332172   710   586   124   345     0   158   86
amappl16   200    27921    0    27084   173   116    57    63     0     8    6
amappl15   192     2449    0     2441     1     0     1     1     0     8    0
amappl14   184     1770    0     1763     1     0     1     1     0     8    0
amappl13   176     1410    0     1406     1     0     1     1     0     8    0
amappl12   168      492    0      487     1     0     1     1     0     8    0
amappl11   160      699    0      687     1     0     1     1     0     8    0
amappl10   152       59    0       57     1     0     1     1     0     8    0
amappl9    144     2125    0     2121     1     0     1     1     0     8    0
amappl8    136     3002    0     2902     4     0     4     4     0     8    0
amappl7    128     1593    0     1579     1     0     1     1     0     8    0
amappl6    120     2080    0     2053     3     2     1     2     0     8    0
amappl5    112     7309    0     7293     1     0     1     1     0     8    0
amappl4    104     3567    0     3536     2     1     1     2     0     8    0
amappl3     96     2099    0     2079     1     0     1     1     0     8    0
amappl2     88     2560    0     2510     3     1     2     3     0     8    0
amappl1     80   173513    0   172965    23    10    13    18     0     8    0
amappl      88   111847    0   111561    10     2     8     8     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      130    0        0     3     0     3     3     0     8    0
uaddrrnd    24     9573    0     9359     2     0     2     2     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     9573    0     9359     2     0     2     2     0     8    0
vmmpekpl   168    69880    0    69795     5     0     5     5     0     8    0
vmmpepl    168   890543    0   887559   417   273   144   173     0   357    2
vmsppl     272     9572    0     9359    15     0    15    15     0     8    0
rwobjpl     24   216404    0   208474    51     1    50    50     0     8    0
pdppl      4096   19152    0    18905   789   538   251   252     0     8    4
pvpl        32  4560143    0  4536298   553   325   228   259     0   265   15
pmappl     216     9572    0     9359    12     0    12    12     0     8    0
extentpl    40       57    0       38     1     0     1     1     0     8    0
phpool     112     2521    0     1370    34     0    34    34     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:440
panic(ffffffff82549a0b) at panic+0x161 sys/kern/subr_prf.c:202
__assert(ffffffff825b952b,ffffffff825dcd39,9e,ffffffff82566db3) at __assert+0x25 sys/kern/subr_prf.c:161
dtopen(31e6e,1,2000,ffff800026539268) at dtopen+0x1c4 sys/dev/dt/dt_dev.c:158
spec_open_clone(ffff80002ea1d088) at spec_open_clone+0x204
spec_open(ffff80002ea1d088) at spec_open+0x3f5 sys/kern/spec_vnops.c:155
VOP_OPEN(fffffd80693f0860,1,fffffd807f7d88a0,ffff800026539268) at VOP_OPEN+0x6c sys/kern/vfs_vops.c:138
vn_open(ffff80002ea1d2d8,1,0) at vn_open+0x467 sys/kern/vfs_vnops.c:183
doopenat(ffff800026539268,ffffff9c,20000000,0,0,ffff80002ea1d4c0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1128
syscall(ffff80002ea1d530) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3ed9365a910, count: -11
ddb> machine ddbcpu 1
No such command
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440
panic(ffffffff82549a0b) at panic+0x161 sys/kern/subr_prf.c:202
__assert(ffffffff825b952b,ffffffff825dcd39,9e,ffffffff82566db3) at __assert+0x25 sys/kern/subr_prf.c:161
dtopen(31e6e,1,2000,ffff800026539268) at dtopen+0x1c4 sys/dev/dt/dt_dev.c:158
spec_open_clone(ffff80002ea1d088) at spec_open_clone+0x204
spec_open(ffff80002ea1d088) at spec_open+0x3f5 sys/kern/spec_vnops.c:155
VOP_OPEN(fffffd80693f0860,1,fffffd807f7d88a0,ffff800026539268) at VOP_OPEN+0x6c sys/kern/vfs_vops.c:138
vn_open(ffff80002ea1d2d8,1,0) at vn_open+0x467 sys/kern/vfs_vnops.c:183
doopenat(ffff800026539268,ffffff9c,20000000,0,0,ffff80002ea1d4c0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1128
syscall(ffff80002ea1d530) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x3ed9365a910, count: -11

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/01/23 15:44 openbsd 1f6b1162831e 214351e1 .config console log report ci-openbsd-main assert "dtlookup(unit) == NULL" failed in dt_dev.c
* Struck through repros no longer work on HEAD.