syzbot


uvm_fault: ml_dequeue

Status: auto-closed as invalid on 2020/10/22 20:43
Reported-by: syzbot+8b682a2764314ba24fc9@syzkaller.appspotmail.com
First crash: 1625d, last: 1583d

Sample crash report:
uvm_fault(0xffffffff828aca30, 0xfffffd0000000008, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at      ml_dequeue+0x28:        movq    0x8(%r14),%rax
ddb{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
kernel page fault
uvm_fault(0xffffffff828aca30, 0xfffffd0000000008, 0, 1) -> e
ml_dequeue(ffff800000b12648) at ml_dequeue+0x28 sys/kern/uipc_mbuf.c:1597
end trace frame: 0xffff800021f1d770, count: 0
ddb{0}> trace
ml_dequeue(ffff800000b12648) at ml_dequeue+0x28 sys/kern/uipc_mbuf.c:1597
ifq_deq_sleep(ffff800000af3a78,ffff800021f1d788,10,117,ffffffff82427d01,ffff800000af3e7c) at ifq_deq_sleep+0x118 sys/net/ifq.c:475
tun_dev_read(5d01,ffff800021f1da58,10) at tun_dev_read+0xd6 sys/net/if_tun.c:775
spec_read(ffff800021f1d8a0) at spec_read+0xf1 sys/kern/spec_vnops.c:222
VOP_READ(fffffd806eceb0d8,ffff800021f1da58,10,fffffd807f7bf7e0) at VOP_READ+0xbf sys/kern/vfs_vops.c:247
vn_read(fffffd807d2880b8,ffff800021f1da58,0) at vn_read+0x124 sys/kern/vfs_vnops.c:375
dofilereadv(ffff800020e38878,f0,ffff800021f1da58,0,ffff800021f1db40) at dofilereadv+0x1a1 sys/kern/sys_generic.c:237
sys_read(ffff800020e38878,ffff800021f1daf0,ffff800021f1db40) at sys_read+0x83 sys/kern/sys_generic.c:157
syscall(ffff800021f1dbc0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800021f1dbc0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xe33d0ca3f90, count: -10
ddb{0}> show registers
rdi               0xffffffff821c1e40    ml_dequeue+0x20
rsi                            0x134
rbp               0xffff800021f1d6c0
rbx               0xfffffd0000000000
rdx                            0x135
rcx               0xffff8000230d4000
rax               0xffff8000230d4000
r8                0xffffffff82427d01    pp_r600_decoded_lanes+0x6850
r9                0xffff800000af3e7c
r10                              0xa
r11               0x668350b9328b6a9d
r12                            0x117
r13               0xffff800000af3e7c
r14               0xfffffd0000000000
r15               0xffff800000b12648
rip               0xffffffff821c1e48    ml_dequeue+0x28
cs                               0x8
rflags                       0x10286    __ALIGN_SIZE+0xf286
rsp               0xffff800021f1d690
ss                              0x10
ml_dequeue+0x28:        movq    0x8(%r14),%rax
ddb{0}> show proc
PROC (syz-executor.1) pid=69237 stat=onproc
    flags process=0 proc=4000000<THREAD>
    pri=32, usrpri=86, nice=20
    forw=0xffffffffffffffff, list=0xffff800020e37c48,0xffffffff8292eea0
    process=0xffff800020df1370 user=0xffff800021f18000, vmspace=0xfffffd807effea10
    estcpu=36, cpticks=1, pctcpu=0.0
    user=0, sys=1, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
  8294  219498  96160      0  2           0                syz-executor.1
* 8294   69237  96160      0  7   0x4000000                syz-executor.1
 85644  263714  41722      0  7           0                syz-executor.0
 85644  183416  41722      0  2   0x4000000                syz-executor.0
 96160   48446  25295      0  3        0x82  nanosleep     syz-executor.1
 41722  359575  25295      0  3        0x82  nanosleep     syz-executor.0
 25295  427337  93870      0  3        0x82  thrsleep      syz-fuzzer
 25295  348849  93870      0  3   0x4000082  nanosleep     syz-fuzzer
 25295  520784  93870      0  3   0x4000082  thrsleep      syz-fuzzer
 25295  138636  93870      0  3   0x4000082  thrsleep      syz-fuzzer
 25295  226740  93870      0  3   0x4000082  thrsleep      syz-fuzzer
 25295  419576  93870      0  3   0x4000082  thrsleep      syz-fuzzer
 25295  372475  93870      0  3   0x4000082  thrsleep      syz-fuzzer
 25295  188017  93870      0  3   0x4000082  thrsleep      syz-fuzzer
 25295  225674  93870      0  3   0x4000082  kqread        syz-fuzzer
 25295  522873  93870      0  3   0x4000082  thrsleep      syz-fuzzer
 93870  156474  58946      0  3    0x10008a  pause         ksh
 58946  487030  59742      0  3        0x92  select        sshd
 62047  190961      1      0  3    0x100083  ttyin         getty
 59742  309571      1      0  3        0x80  select        sshd
 10508  160689  80699     74  3    0x100092  bpf           pflogd
 80699   46786      1      0  3        0x80  netio         pflogd
 49069    4425  74199     73  3    0x100090  kqread        syslogd
 74199  363276      1      0  3    0x100082  netio         syslogd
 81646  159850      1     77  3    0x100090  poll          dhclient
 91445   79972      1      0  3        0x80  poll          dhclient
  6563  455529      0      0  3     0x14200  bored         smr
 51809  249475      0      0  2     0x14200                zerothread
 93322  104265      0      0  3     0x14200  aiodoned      aiodoned
 34948  174324      0      0  3     0x14200  syncer        update
 17531  277509      0      0  3     0x14200  cleaner       cleaner
 45318  469533      0      0  3     0x14200  reaper        reaper
 47797  426046      0      0  3     0x14200  pgdaemon      pagedaemon
 61905  463027      0      0  3     0x14200  bored         crynlk
 55909  265192      0      0  3     0x14200  bored         crypto
 54959  354930      0      0  3  0x40014200  acpi0         acpi0
 98613  451878      0      0  3  0x40014200                idle1
  2305  111379      0      0  3     0x14200  bored         softnet
 26592  397436      0      0  3     0x14200  bored         systqmp
 62923  319442      0      0  3     0x14200  bored         systq
 33008  471356      0      0  3  0x40014200  bored         softclock
  8400   36712      0      0  3  0x40014200                idle0
     1   44948      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{0}> show all locks
CPU 0:
exclusive mutex &ifq->ifq_mtx r = 0 (0xffff800000af3aa0)
#0  witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline]
#0  witness_lock+0x4c7 sys/kern/subr_witness.c:1164
#1  mtx_enter_try+0x102
#2  mtx_enter+0x4b sys/kern/kern_lock.c:266
#3  ifq_deq_sleep+0x4c sys/net/ifq.c:468
#4  tun_dev_read+0xd6 sys/net/if_tun.c:775
#5  spec_read+0xf1 sys/kern/spec_vnops.c:222
#6  VOP_READ+0xbf sys/kern/vfs_vops.c:247
#7  vn_read+0x124 sys/kern/vfs_vnops.c:375
#8  dofilereadv+0x1a1 sys/kern/sys_generic.c:237
#9  sys_read+0x83 sys/kern/sys_generic.c:157
#10 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#10 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#11 Xsyscall+0x128
Process 8294 (syz-executor.1) thread 0xffff800020e38878 (69237)
exclusive kernel_lock &kernel_lock r = 1 (0xffffffff828c5528)
#0  witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline]
#0  witness_lock+0x4c7 sys/kern/subr_witness.c:1164
#1  vn_read+0x45 sys/kern/vfs_vnops.c:357
#2  dofilereadv+0x1a1 sys/kern/sys_generic.c:237
#3  sys_read+0x83 sys/kern/sys_generic.c:157
#4  syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#4  syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#5  Xsyscall+0x128
exclusive mutex &ifq->ifq_mtx r = 0 (0xffff800000af3aa0)
#0  witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline]
#0  witness_lock+0x4c7 sys/kern/subr_witness.c:1164
#1  mtx_enter_try+0x102
#2  mtx_enter+0x4b sys/kern/kern_lock.c:266
#3  ifq_deq_sleep+0x4c sys/net/ifq.c:468
#4  tun_dev_read+0xd6 sys/net/if_tun.c:775
#5  spec_read+0xf1 sys/kern/spec_vnops.c:222
#6  VOP_READ+0xbf sys/kern/vfs_vops.c:247
#7  vn_read+0x124 sys/kern/vfs_vnops.c:375
#8  dofilereadv+0x1a1 sys/kern/sys_generic.c:237
#9  sys_read+0x83 sys/kern/sys_generic.c:157
#10 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#10 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#11 Xsyscall+0x128
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf  9493   6410K    6672K  78643K     10913        0
            pcb    13      8K       8K  78643K        67        0
         rtable   115      4K       5K  78643K       372        0
         ifaddr    60     12K      13K  78643K       105        0
         sysctl     2      0K       0K  78643K         4        0
       counters    43     33K      34K  78643K        51        0
       ioctlops     0      0K       4K  78643K      1490        0
            iov     0      0K      16K  78643K        50        0
          mount     1      1K       1K  78643K         1        0
         vnodes  1219     77K      77K  78643K      1336        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       5K  78643K         6        0
         VM map     2      1K       1K  78643K         2        0
            sem    12      0K       0K  78643K        89        0
        dirhash    12      2K       2K  78643K        12        0
           ACPI  1824    197K     290K  78643K     13058        0
      file desc     6     17K      25K  78643K       330        0
          sigio     0      0K       0K  78643K         6        0
           proc    60     63K      95K  78643K       491        0
        subproc    32      2K       2K  78643K        51        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
    ip_moptions     0      0K       0K  78643K       419        0
       in_multi    44      2K       3K  78643K       137        0
    ether_multi     1      0K       0K  78643K         2        0
            mrt     0      0K       0K  78643K         2        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys    37    175K     175K  78643K        37        0
           exec     0      0K       1K  78643K       228        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   120     39K      39K  78643K      2015        0
       UVM aobj    11      2K       2K  78643K        11        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
    ip6_options     0      0K       0K  78643K        30        0
            NDP     9      0K       0K  78643K        30        0
           temp   104   3858K    3922K  78643K      4457        0
         kqueue     3      4K       8K  78643K        10        0
      SYN cache     2     16K      16K  78643K         2        0
ddb{0}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp         64       10    0        4     1     0     1     1     0     8    0
plcache    128       20    0        0     1     0     1     1     0     8    0
rtpcb       80       33    0       31     1     0     1     1     0     8    0
rtentry    112       86    0       39     2     0     2     2     0     8    0
unpcb      120      131    0      121     1     0     1     1     0     8    0
syncache   264        6    0        6     2     2     0     1     0     8    0
tcpqe       32        9    0        9     1     1     0     1     0     8    0
tcpcb      544      319    0      311     1     0     1     1     0     8    0
inpcb      296      723    0      710     2     0     2     2     0     8    1
rttmr       72        1    0        1     1     0     1     1     0     8    1
nd6         48       27    0       19     1     0     1     1     0     8    0
pffrag     232        4    0        4     2     1     1     1     0   482    1
pffrnode    88        4    0        4     2     1     1     1     0     8    1
pffrent     40       94    0       94     2     1     1     1     0     8    1
pfosfp      40      846    0      423     5     0     5     5     0     8    0
pfosfpen   112     1428    0      714    21     0    21    21     0     8    0
pfrktable  1344       9    0        9     2     1     1     1     0     8    1
pfstitem    24       37    0        6     1     0     1     1     0     8    0
pfstkey    112       37    0        6     1     0     1     1     0     8    0
pfstate    328       37    0        6     3     0     3     3     0     8    0
pfrule     1360      24    0       18     2     0     2     2     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      322    0      103    15     1    14    14     0     8    0
art_table   32      323    0      103     2     0     2     2     0     8    0
art_node    16       85    0       43     1     0     1     1     0     8    0
sysvmsgpl   40       30    0       18     1     0     1     1     0     8    0
semupl     112        3    0        3     1     1     0     1     0     8    0
semapl     112       86    0       76     1     0     1     1     0     8    0
shmpl      112        8    0        0     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256     1770    0      365    89     1    88    89     0     8    0
ffsino     272     1770    0      365    96     2    94    95     0     8    0
nchpl      144     2390    0      794    60     0    60    60     0     8    0
uvmvnodes   72     1908    0        0    35     0    35    35     0     8    0
vnodes     208     1908    0        0   101     0   101   101     0     8    0
namei      1024    6359    0     6359     2     1     1     1     0     8    1
percpumem   16       36    0        4     1     0     1     1     0     8    0
vcpupl     1984       1    0        0     1     0     1     1     0     8    0
vmpool     560        1    0        0     1     0     1     1     0     8    0
pfiaddrpl  120        3    0        3     2     1     1     1     0     8    1
scxspl     192     7309    0     7309     8     7     1     7     0     8    1
plimitpl   152       38    0       30     1     0     1     1     0     8    0
sigapl     424      542    0      510     4     0     4     4     0     8    0
futexpl     56     4293    0     4293     1     0     1     1     0     8    1
knotepl    112       83    0       64     1     0     1     1     0     8    0
kqueuepl   144       28    0       26     1     0     1     1     0     8    0
pipepl     304      105    0       95     2     1     1     2     0     8    0
fdescpl    496      527    0      510     3     0     3     3     0     8    0
filepl     152     2834    0     2728     6     1     5     5     0     8    0
lockfpl    104       54    0       53     1     0     1     1     0     8    0
lockfspl    48       20    0       19     1     0     1     1     0     8    0
sessionpl  112       19    0        8     1     0     1     1     0     8    0
pgrppl      48       23    0       12     1     0     1     1     0     8    0
ucredpl     96      184    0      175     1     0     1     1     0     8    0
zombiepl   144      510    0      510     2     1     1     1     0     8    1
processpl  992      542    0      510     6     1     5     5     0     8    1
procpl     624     1193    0     1150     4     0     4     4     0     8    0
sockpl     400      887    0      862     6     3     3     4     0     8    0
mcl64k     65536     12    0        0     2     0     2     2     0     8    0
mcl12k     12288      5    0        0     1     0     1     1     0     8    0
mcl9k      9216       2    0        0     1     0     1     1     0     8    0
mcl8k      8192       2    0        0     1     0     1     1     0     8    0
mcl4k      4096       6    0        0     1     0     1     1     0     8    0
mcl2k2     2112       1    0        0     1     0     1     1     0     8    0
mcl2k      2048     192    0        0    23     0    23    23     0     8    0
mtagpl      96       33    0        0     1     0     1     1     0     8    0
mbufpl     256      552    0        0    33     0    33    33     0     8    0
bufpl      280     4001    0      132   277     0   277   277     0     8    0
anonpl      16    79436    0    62442    85     1    84    84     0   124   11
amapchunkpl 152    3069    0     2906    14     7     7    14     0   158    0
amappl16   192     2786    0     1854    67     8    59    59     0     8   12
amappl15   184        9    0        8     2     1     1     1     0     8    0
amappl14   176      171    0      165     1     0     1     1     0     8    0
amappl13   168       74    0       71     1     0     1     1     0     8    0
amappl12   160       49    0       46     1     0     1     1     0     8    0
amappl11   152      209    0      191     1     0     1     1     0     8    0
amappl10   144       21    0       15     1     0     1     1     0     8    0
amappl9    136      478    0      475     1     0     1     1     0     8    0
amappl8    128      466    0      432     2     0     2     2     0     8    0
amappl7    120      125    0      113     1     0     1     1     0     8    0
amappl6    112      175    0      168     1     0     1     1     0     8    0
amappl5    104      238    0      221     1     0     1     1     0     8    0
amappl4     96      697    0      665     1     0     1     1     0     8    0
amappl3     88      152    0      147     1     0     1     1     0     8    0
amappl2     80     3166    0     3091     2     0     2     2     0     8    0
amappl1     72    24864    0    24403    23    13    10    18     0     8    0
amappl      80     1466    0     1418     2     0     2     2     0    84    0
dma4096    4096       1    0        1     1     1     0     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      64       10    0        0     1     0     1     1     0     8    0
uaddrrnd    24      528    0      510     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      528    0      510     1     0     1     1     0     8    0
vmmpekpl   168     7989    0     7955     2     0     2     2     0     8    0
vmmpepl    168    75796    0    73586   131    13   118   128     0   357   21
vmsppl     368      527    0      510     2     0     2     2     0     8    0
pdppl      4096    1063    0     1021     7     1     6     6     0     8    0
pvpl        32   230198    0   209950   202     4   198   198     0   265   30
pmappl     232      527    0      510     3     1     2     2     0     8    1
extentpl    40       53    0       36     1     0     1     1     0     8    0
phpool     112      290    0       11     8     0     8     8     0     8    0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
ml_dequeue(ffff800000b12648) at ml_dequeue+0x28 sys/kern/uipc_mbuf.c:1597
ifq_deq_sleep(ffff800000af3a78,ffff800021f1d788,10,117,ffffffff82427d01,ffff800000af3e7c) at ifq_deq_sleep+0x118 sys/net/ifq.c:475
tun_dev_read(5d01,ffff800021f1da58,10) at tun_dev_read+0xd6 sys/net/if_tun.c:775
spec_read(ffff800021f1d8a0) at spec_read+0xf1 sys/kern/spec_vnops.c:222
VOP_READ(fffffd806eceb0d8,ffff800021f1da58,10,fffffd807f7bf7e0) at VOP_READ+0xbf sys/kern/vfs_vops.c:247
vn_read(fffffd807d2880b8,ffff800021f1da58,0) at vn_read+0x124 sys/kern/vfs_vnops.c:375
dofilereadv(ffff800020e38878,f0,ffff800021f1da58,0,ffff800021f1db40) at dofilereadv+0x1a1 sys/kern/sys_generic.c:237
sys_read(ffff800020e38878,ffff800021f1daf0,ffff800021f1db40) at sys_read+0x83 sys/kern/sys_generic.c:157
syscall(ffff800021f1dbc0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800021f1dbc0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xe33d0ca3f90, count: -10
ddb{0}> machine ddbcpu 1
Stopped at      x86_ipi_db+0x1a:        addq    $0x8,%rsp
ddb{1}> trace
x86_ipi_db(ffff800020d70ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352
x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23
sys_clock_gettime(ffff800020e37eb8,ffff800021ee9140,ffff800021ee9190) at sys_clock_gettime+0x67 sys/kern/kern_time.c:168
syscall(ffff800021ee9210) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800021ee9210) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffde4c0, count: -6

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/07/24 20:42 openbsd 6e780b9a59f4 554af388 .config console log report ci-openbsd-multicore
2020/06/12 22:40 openbsd 50f19d1942a4 d1c1c849 .config console log report ci-openbsd-main
* Struck through repros no longer work on HEAD.