syzbot


panic: poWoAlR_NcIaNchGe_i:te Sm_PmLa gNic_OcTh eLckO:W mEbRuEfD plON c pSuY SfCrAeeL Lli s2 t 9m2o7d3i5f0i4e2d:LINE it

Status: closed as dup on 2020/03/10 19:36
Reported-by: syzbot+f91756de3a351f36a7bf@syzkaller.appspotmail.com
First crash: 1717d, last: 1717d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
pool: cpu free list modified: mbufpl syz 15863 1570d 1856d

Sample crash report:
panic: poWoAlR_NcIaNchGe_i:te Sm_PmLa gNic_OcTh eLckO:W mEbRuEfD plON c pSuY SfCrAeeL Lli s2 t 9m2o7d3i5f0i4e2d:8  itEeXmI Ta d0d ar
 
0xStopped at      savectx+0xb1:   movl    $0,%gs:0x530
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*199654  57141      0         0x2          0    0  syz-executor.0
 449209  84377      0     0x14000      0x200    1  softnet
savectx() at savectx+0xb1
end of kernel
end trace frame: 0x7f7ffffc0740, 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{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd807badf800+16 0x0!=0x8a053df07c6c71c7
ddb{0}> trace
savectx() at savectx+0xb1
end of kernel
end trace frame: 0x7f7ffffc0740, count: -1
ddb{0}> show registers
rdi                                0
rsi                                0
rbp               0xffff800020b6b1a0
rbx                                0
rdx               0xffff800020a6c758
rcx                                0
rax                             0x39
r8                0xffffffff817c6bdf    kprintf+0x16f
r9                               0x1
r10                             0x25
r11               0x948be3428968db79
r12                                0
r13                                0
r14               0xffff800020a6c758
r15                                0
rip               0xffffffff813683f1    savectx+0xb1
cs                               0x8
rflags                          0x46
rsp               0xffff800020b6b120
ss                              0x10
savectx+0xb1:   movl    $0,%gs:0x530
ddb{0}> show proc
PROC (syz-executor.0) pid=199654 stat=onproc
    flags process=2<EXEC> proc=0
    pri=74, usrpri=74, nice=20
    forw=0xffffffffffffffff, list=0xffff800020a6c4e8,0xffff800020ac7d68
    process=0xffff800020a803d0 user=0xffff800020b66000, vmspace=0xfffffd807f0002e0
    estcpu=24, cpticks=1, pctcpu=0.19
    user=0, sys=1, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 54016  446415  57141      0  2           0                syz-executor.0
 69625  234339      0      0  3     0x14200  bored         sosplice
 13365  269330  95477      0  3         0x2  biowait       syz-executor.1
*57141  199654  95477      0  7         0x2                syz-executor.0
 95477   54438  55197      0  3        0x82  thrsleep      syz-fuzzer
 95477   80232  55197      0  3   0x4000082  nanosleep     syz-fuzzer
 95477  167883  55197      0  3   0x4000082  thrsleep      syz-fuzzer
 95477  182341  55197      0  3   0x4000082  thrsleep      syz-fuzzer
 95477  207573  55197      0  3   0x4000082  thrsleep      syz-fuzzer
 95477  298135  55197      0  3   0x4000082  kqread        syz-fuzzer
 95477  138687  55197      0  3   0x4000082  thrsleep      syz-fuzzer
 95477  284326  55197      0  3   0x4000082  thrsleep      syz-fuzzer
 95477  508592  55197      0  3   0x4000082  thrsleep      syz-fuzzer
 95477  110047  55197      0  3   0x4000082  nanosleep     syz-fuzzer
 55197  419543  63910      0  3    0x10008a  pause         ksh
 63910  274751  73955      0  3        0x92  select        sshd
 46943  169040      1      0  3    0x100083  ttyin         getty
 73955  433733      1      0  3        0x80  select        sshd
 84456   57952  61365     74  3    0x100092  bpf           pflogd
 61365  518711      1      0  3        0x80  netio         pflogd
 40110   97727  79795     73  3    0x100090  kqread        syslogd
 79795  141701      1      0  3    0x100082  netio         syslogd
  9085  278260      1     77  3    0x100090  poll          dhclient
 34493  404207      1      0  3        0x80  poll          dhclient
 72841  206454      0      0  3     0x14200  bored         smr
 15738  108708      0      0  3     0x14200  pgzero        zerothread
 79165  256471      0      0  3     0x14200  aiodoned      aiodoned
 28397  513442      0      0  3     0x14200  syncer        update
 39119  476457      0      0  3     0x14200  cleaner       cleaner
 34427   76330      0      0  3     0x14200  reaper        reaper
 54669  228504      0      0  3     0x14200  pgdaemon      pagedaemon
 36162  321972      0      0  3     0x14200  bored         crynlk
 44400   95049      0      0  3     0x14200  bored         crypto
 95827  451771      0      0  3  0x40014200  acpi0         acpi0
 11421  214291      0      0  3  0x40014200                idle1
 84377  449209      0      0  7     0x14200                softnet
 93926  269730      0      0  3     0x14200  bored         systqmp
 31566  434531      0      0  3     0x14200  bored         systq
 47797   82097      0      0  3  0x40014200  bored         softclock
 29441  230436      0      0  3  0x40014200                idle0
     1  356212      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{0}> show all locks
CPU 0:
exclusive mutex vmmpepl r = 0 (0xffffffff8263e678)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  mtx_enter_try+0x102
#2  mtx_enter+0x4b sys/kern/kern_lock.c:266
#3  pool_get+0xbf sys/kern/subr_pool.c:578
#4  uvm_mapent_alloc+0x2d2 sys/uvm/uvm_map.c:1751
#5  uvm_map_mkentry+0x75 sys/uvm/uvm_map.c:1656
#6  uvm_mapent_clone+0x9e sys/uvm/uvm_map.c:3778
#7  uvm_mapent_forkcopy+0x6a sys/uvm/uvm_map.c:3879
#8  uvmspace_fork+0x226
#9  process_new+0x16c sys/kern/kern_fork.c:257
#10 fork1+0x31b sys/kern/kern_fork.c:376
#11 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#11 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#12 Xsyscall+0x128
Process 13365 (syz-executor.1) thread 0xffff800020ac7d58 (269330)
exclusive rrwlock inode r = 0 (0xfffffd80638d73d0)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  rw_enter+0x453 sys/kern/kern_rwlock.c:311
#2  rrw_enter+0x88 sys/kern/kern_rwlock.c:462
#3  VOP_LOCK+0x4b sys/kern/vfs_vops.c:602
#4  vn_lock+0x81 sys/kern/vfs_vnops.c:575
#5  vget+0x1c8 sys/kern/vfs_subr.c:671
#6  ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119
#7  ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1329
#8  ufs_lookup+0x14b7 sys/ufs/ufs/ufs_lookup.c:487
#9  VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:90
#10 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568
#11 namei+0x63c sys/kern/vfs_lookup.c:249
#12 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1860
#13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#14 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffffd806b44e098)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  rw_enter+0x453 sys/kern/kern_rwlock.c:311
#2  rrw_enter+0x88 sys/kern/kern_rwlock.c:462
#3  VOP_LOCK+0x4b sys/kern/vfs_vops.c:602
#4  vn_lock+0x81 sys/kern/vfs_vnops.c:575
#5  vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419
#6  namei+0x63c sys/kern/vfs_lookup.c:249
#7  dounlinkat+0x99 sys/kern/vfs_syscalls.c:1860
#8  syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#8  syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#9  Xsyscall+0x128
Process 57141 (syz-executor.0) thread 0xffff800020a6c758 (199654)
exclusive rwlock vmmaplk r = 0 (0xfffffd80627da478)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  rw_enter+0x453 sys/kern/kern_rwlock.c:311
#2  vm_map_lock_ln+0x111 sys/uvm/uvm_map.c:5448
#3  uvmspace_fork+0x113 sys/uvm/uvm_map.c:4072
#4  process_new+0x16c sys/kern/kern_fork.c:257
#5  fork1+0x31b sys/kern/kern_fork.c:376
#6  syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#6  syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#7  Xsyscall+0x128
exclusive rwlock vmmaplk r = 0 (0xfffffd807f0002f8)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  rw_enter+0x453 sys/kern/kern_rwlock.c:311
#2  vm_map_lock_ln+0x111 sys/uvm/uvm_map.c:5448
#3  uvmspace_fork+0x37 sys/uvm/uvm_map.c:4063
#4  process_new+0x16c sys/kern/kern_fork.c:257
#5  fork1+0x31b sys/kern/kern_fork.c:376
#6  syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#6  syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#7  Xsyscall+0x128
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82634b10)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  syscall+0x400 mi_syscall sys/sys/syscall_mi.h:93 [inline]
#1  syscall+0x400 sys/arch/amd64/amd64/trap.c:570
#2  Xsyscall+0x128
exclusive mutex vmmpepl r = 0 (0xffffffff8263e678)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  mtx_enter_try+0x102
#2  mtx_enter+0x4b sys/kern/kern_lock.c:266
#3  pool_get+0xbf sys/kern/subr_pool.c:578
#4  uvm_mapent_alloc+0x2d2 sys/uvm/uvm_map.c:1751
#5  uvm_map_mkentry+0x75 sys/uvm/uvm_map.c:1656
#6  uvm_mapent_clone+0x9e sys/uvm/uvm_map.c:3778
#7  uvm_mapent_forkcopy+0x6a sys/uvm/uvm_map.c:3879
#8  uvmspace_fork+0x226
#9  process_new+0x16c sys/kern/kern_fork.c:257
#10 fork1+0x31b sys/kern/kern_fork.c:376
#11 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#11 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#12 Xsyscall+0x128
Process 84377 (softnet) thread 0xffff800020a18750 (449209)
shared rwlock netlock r = 0 (0xffffffff824ec4d8)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  if_input_process+0x84 sys/net/if.c:941
#2  ifiq_process+0x80 sys/net/ifq.c:646
#3  taskq_thread+0x9c sys/kern/kern_task.c:369
#4  proc_trampoline+0x1c
shared rwlock softnet r = 0 (0xffff80000002b0e0)
#0  witness_lock+0x52e sys/kern/subr_witness.c:1164
#1  taskq_thread+0x8f sys/kern/kern_task.c:368
#2  proc_trampoline+0x1c
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf  9518   6415K    7063K  78643K     11365        0
            pcb    13      8K       8K  78643K        80        0
         rtable    97      3K       3K  78643K       299        0
         ifaddr    82     16K      17K  78643K       129        0
       counters    43     33K      34K  78643K        55        0
       ioctlops     0      0K       4K  78643K      1496        0
            iov     0      0K      16K  78643K       203        0
          mount     1      1K       1K  78643K         1        0
         vnodes  1220     77K      77K  78643K      1430        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       5K  78643K        13        0
         VM map     2      1K       1K  78643K         2        0
            sem    12      1K       1K  78643K        34        0
        dirhash    12      2K       2K  78643K        12        0
           ACPI  1809    196K     290K  78643K     12766        0
      file desc     5     13K      25K  78643K       289        0
          sigio     0      0K       0K  78643K         3        0
           proc    61     63K      95K  78643K       478        0
        subproc    32      2K       2K  78643K        34        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
    ip_moptions     0      0K       0K  78643K        49        0
       in_multi    73      3K       3K  78643K       129        0
    ether_multi     1      0K       0K  78643K        12        0
            mrt     0      0K       0K  78643K         6        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys    49    228K     228K  78643K        49        0
           exec     0      0K       1K  78643K       231        0
     pfkey data     0      0K       0K  78643K         2        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   122    103K     103K  78643K      1902        0
       UVM aobj    26      2K       2K  78643K        43        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
    ip6_options     0      0K       0K  78643K        54        0
            NDP    12      0K       0K  78643K        25        0
           temp   122   3024K    3088K  78643K      4843        0
         kqueue     3      4K      16K  78643K        20        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        6    0        1     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       62    0       22     2     0     2     2     0     8    0
unpcb      120      282    0      271     1     0     1     1     0     8    0
syncache   264        6    0        6     2     2     0     1     0     8    0
tcpqe       32       12    0       12     1     1     0     1     0     8    0
tcpcb      544      120    0      116     1     0     1     1     0     8    0
inpcb      280      437    0      430     2     0     2     2     0     8    1
rttmr       72        2    0        2     1     0     1     1     0     8    1
nd6         48       10    0        6     1     0     1     1     0     8    0
pkpcb       40        2    0        2     1     1     0     1     0     8    0
pffrag     232        4    0        4     2     2     0     1     0   482    0
pffrnode    88        4    0        4     2     2     0     1     0     8    0
pffrent     40      180    0      180     2     2     0     1     0     8    0
pfosfp      40      846    0      423     5     0     5     5     0     8    0
pfosfpen   112     1428    0      714    21     0    21    21     0     8    0
pfstitem    24       39    0        7     1     0     1     1     0     8    0
pfstkey    112       39    0        7     1     0     1     1     0     8    0
pfstate    328       39    0        7     3     0     3     3     0     8    0
pfrule     1360      21    0       16     2     1     1     2     0     8    0
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256      267    0       91    13     0    13    13     0     8    0
art_table   32      268    0       91     2     0     2     2     0     8    0
art_node    16       61    0       24     1     0     1     1     0     8    0
sysvmsgpl   40       38    0       19     1     0     1     1     0     8    0
semupl     112        2    0        2     1     1     0     1     0     8    0
semapl     112       26    0       16     1     0     1     1     0     8    0
shmpl      112       41    0       17     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino1pl    128     1795    0      391    46     0    46    46     0     8    0
ffsino     272     1795    0      391    95     0    95    95     0     8    0
nchpl      144     2541    0      928    61     0    61    61     0     8    0
uvmvnodes   72     2008    0        0    37     0    37    37     0     8    0
vnodes     208     2008    0        0   106     0   106   106     0     8    0
namei      1024    7530    0     7530     1     0     1     1     0     8    1
percpumem   16       38    0        6     1     0     1     1     0     8    0
vcpupl     1984      13    0        0     2     0     2     2     0     8    0
vmpool     560       13    0        0     1     0     1     1     0     8    0
scxspl     192     7506    0     7505     8     7     1     7     0     8    0
plimitpl   152       36    0       28     1     0     1     1     0     8    0
sigapl     424      505    0      473     4     0     4     4     0     8    0
futexpl     56     5832    0     5832     1     0     1     1     0     8    1
knotepl    112       74    0       55     1     0     1     1     0     8    0
kqueuepl   144      133    0      131     1     0     1     1     0     8    0
pipelkpl    48      155    0      145     1     0     1     1     0     8    0
pipepl     120      310    0      291     2     1     1     2     0     8    0
fdescpl    496      489    0      473     3     0     3     3     0     8    0
filepl     152     3573    0     3473     6     1     5     6     0     8    1
lockfpl    104      155    0      154     1     0     1     1     0     8    0
lockfspl    48       48    0       47     1     0     1     1     0     8    0
sessionpl  112       18    0        7     1     0     1     1     0     8    0
pgrppl      48       22    0       11     1     0     1     1     0     8    0
ucredpl     96      321    0      312     1     0     1     1     0     8    0
zombiepl   144      473    0      473     1     0     1     1     0     8    1
processpl  960      505    0      473     5     0     5     5     0     8    0
procpl     624     1120    0     1079     4     0     4     4     0     8    0
sosppl     128       13    0       13     1     0     1     1     0     8    1
sockpl     400      760    0      740     5     1     4     4     0     8    1
mcl64k     65536      6    0        0     1     0     1     1     0     8    0
mcl16k     16384      1    0        0     1     0     1     1     0     8    0
mcl12k     12288      2    0        0     1     0     1     1     0     8    0
mcl9k      9216       2    0        0     1     0     1     1     0     8    0
mcl8k      8192       5    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     201    0        0    25     0    25    25     0     8    0
mtagpl      80       26    0        0     1     0     1     1     0     8    0
mbufpl     256      319    0        0    20     0    20    20     0     8    0
bufpl      280     6840    0      573   448     0   448   448     0     8    0
anonpl      16    61393    0    44130    87     7    80    86     0   124    9
amapchunkpl 152    2777    0     2639    13     6     7    13     0   158    0
amappl16   192     2428    0     1484    60    11    49    60     0     8    1
amappl15   184        2    0        1     2     1     1     1     0     8    0
amappl14   176        6    0        3     2     1     1     1     0     8    0
amappl13   168      155    0      153     1     0     1     1     0     8    0
amappl12   160       14    0       12     1     0     1     1     0     8    0
amappl11   152      195    0      176     1     0     1     1     0     8    0
amappl10   144       28    0       22     1     0     1     1     0     8    0
amappl9    136      390    0      387     1     0     1     1     0     8    0
amappl8    128      320    0      294     1     0     1     1     0     8    0
amappl7    120      119    0      108     1     0     1     1     0     8    0
amappl6    112      153    0      147     1     0     1     1     0     8    0
amappl5    104      390    0      375     1     0     1     1     0     8    0
amappl4     96      638    0      606     2     1     1     2     0     8    0
amappl3     88      111    0      106     1     0     1     1     0     8    0
amappl2     80     3002    0     2938     3     1     2     3     0     8    0
amappl1     72    20359    0    19934    25    15    10    20     0     8    0
amappl      80     1374    0     1327     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       42    0       17     1     0     1     1     0     8    0
uaddrrnd    24      502    0      473     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      502    0      473     1     0     1     1     0     8    0
vmmpekpl   168     7755    0     7722     2     0     2     2     0     8    0
vmmpepl    168    67108    0    65025   125    18   107   121     0   357   10
vmsppl     368      501    0      473     3     0     3     3     0     8    0
pdppl      4096    1012    0      959     7     0     7     7     0     8    0
pvpl        32   196745    0   176441   202     6   196   202     0   265   28
pmappl     232      501    0      473     2     0     2     2     0     8    0
extentpl    40       46    0       29     1     0     1     1     0     8    0
phpool     112      186    0        4     6     0     6     6     0     8    0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/03/10 19:25 openbsd bfe2257568b6 35f53e45 .config console log report ci-openbsd-multicore
* Struck through repros no longer work on HEAD.