syzbot


panic:W ApoRNoIlN_Gc:ac hSPeL_ iNtOeTm _LmOaWgERiEcD_ cOheNc Sk:YS CmAbLuLfp 2l -c5p0u7 6fr57e3e3 1l iEsXItT m0od ia

Status: closed as dup on 2020/06/14 07:27
Reported-by: syzbot+02498c03bfcdc029b330@syzkaller.appspotmail.com
First crash: 1622d, last: 1622d
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:W ApoRNoIlN_Gc:ac hSPeL_ iNtOeTm _LmOaWgERiEcD_ cOheNc Sk:YS CmAbLuLfp 2l  -c5p0u7 6fr57e3e3 1l iEsXItT  m0od ia
f
ieStopped at      savectx+0xb1:   movl    $0,%gs:0x530
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*394738  91951      0         0x2          0    1  syz-executor.0
 396219    692      0        0x12          0    0  sshd
savectx() at savectx+0xb1
end of kernel
end trace frame: 0x7f7ffffeaa60, 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{1}> 
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806a618800+24 0x5a53175d924a398!=0x5a531f5b33b0c98
ddb{1}> trace
savectx() at savectx+0xb1
end of kernel
end trace frame: 0x7f7ffffeaa60, count: -1
ddb{1}> show registers
rdi                                0
rsi                                0
rbp               0xffff800020ee9880
rbx                                0
rdx                             0x8b
rcx                              0x2
rax                             0x3a
r8                0xffffffff81e379ff    kprintf+0x16f
r9                               0x1
r10                              0x2
r11               0xd706d097c2d4fb4c
r12                                0
r13                                0
r14               0xffff800020dec4e8
r15                                0
rip               0xffffffff81a2f3f1    savectx+0xb1
cs                               0x8
rflags                          0x46
rsp               0xffff800020ee9800
ss                              0x10
savectx+0xb1:   movl    $0,%gs:0x530
ddb{1}> show proc
PROC (syz-executor.0) pid=394738 stat=onproc
    flags process=2<EXEC,8ORPHAN> proc=0
    pri=17, usrpri=52, nice=20
    forw=0xffffffffffffffff, list=0xffff800020dec758,0xffff800020ee3888
    process=0xffff800020e003e8 user=0xffff800020ee4000, vmspace=0xfffffd807f000cf0
    estcpu=2, cpticks=1, pctcpu=0.5
    user=0, sys=1, intr=0
ddb{1}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 68722  341358  91951      0  2           0                syz-executor.0
 15046  517608   1563      0  2         0x2                syz-executor.1
*91951  394738   1563      0  7         0x2                syz-executor.0
  1563  109044  13133      0  3        0x82  thrsleep      syz-fuzzer
  1563  108191  13133      0  3   0x4000082  nanosleep     syz-fuzzer
  1563  146694  13133      0  3   0x4000082  thrsleep      syz-fuzzer
  1563  328585  13133      0  2   0x4000002                syz-fuzzer
  1563   83246  13133      0  3   0x4000082  thrsleep      syz-fuzzer
  1563   57125  13133      0  2   0x4000002                syz-fuzzer
  1563  233483  13133      0  3   0x4000082  thrsleep      syz-fuzzer
  1563    1002  13133      0  3   0x4000082  thrsleep      syz-fuzzer
  1563  305714  13133      0  3   0x4000082  thrsleep      syz-fuzzer
  1563  236181  13133      0  3   0x4000082  thrsleep      syz-fuzzer
 13133  347515    692      0  3    0x10008a  pause         ksh
   692  396219  25003      0  7        0x12                sshd
 56443  319744      1      0  3    0x100083  ttyin         getty
 25003   77526      1      0  3        0x80  select        sshd
 29203  407144  86951     74  3    0x100092  bpf           pflogd
 86951   30791      1      0  3        0x80  netio         pflogd
 70536  177695  19017     73  3    0x100090  kqread        syslogd
 19017  465942      1      0  3    0x100082  netio         syslogd
 33389  236826      1     77  3    0x100090  poll          dhclient
 93221  329581      1      0  3        0x80  poll          dhclient
 44503  120282      0      0  3     0x14200  bored         smr
 89672  231260      0      0  2     0x14200                zerothread
 68760   64560      0      0  3     0x14200  aiodoned      aiodoned
 13675  473758      0      0  3     0x14200  syncer        update
 14843  259900      0      0  3     0x14200  cleaner       cleaner
  6399  353660      0      0  3     0x14200  reaper        reaper
 59400   90935      0      0  3     0x14200  pgdaemon      pagedaemon
 11261  485883      0      0  3     0x14200  bored         crynlk
 38344  508523      0      0  3     0x14200  bored         crypto
 43355  199549      0      0  3  0x40014200  acpi0         acpi0
 65468  522294      0      0  3  0x40014200                idle1
 64816  212627      0      0  2     0x14200                softnet
 26269  387494      0      0  3     0x14200  bored         systqmp
 77137  468021      0      0  3     0x14200  bored         systq
 57814  467965      0      0  3  0x40014200  bored         softclock
 57529  269536      0      0  3  0x40014200                idle0
     1  249775      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{1}> show all locks
CPU 1:
exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff828a3dd0)
#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  uvm_pmr_getpages+0x34e sys/uvm/uvm_pmemrange.c:941
#4  uvm_pglistalloc+0x362 sys/uvm/uvm_page.c:790
#5  uvm_km_kmemalloc_pla+0x238 sys/uvm/uvm_km.c:367
#6  uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274
#7  fork1+0x271 sys/kern/kern_fork.c:365
#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 91951 (syz-executor.0) thread 0xffff800020dec4e8 (394738)
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff828b3f90)
#0  witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline]
#0  witness_lock+0x4c7 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 &uvm.fpageqlock r = 0 (0xffffffff828a3dd0)
#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  uvm_pmr_getpages+0x34e sys/uvm/uvm_pmemrange.c:941
#4  uvm_pglistalloc+0x362 sys/uvm/uvm_page.c:790
#5  uvm_km_kmemalloc_pla+0x238 sys/uvm/uvm_km.c:367
#6  uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274
#7  fork1+0x271 sys/kern/kern_fork.c:365
#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 692 (sshd) thread 0xffff800020e5f600 (396219)
exclusive rwlock netlock r = 0 (0xffffffff826eda78)
#0  witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline]
#0  witness_lock+0x4c7 sys/kern/subr_witness.c:1164
#1  solock+0x5a sys/kern/uipc_socket2.c:282
#2  sosend+0x559 sys/kern/uipc_socket.c:537
#3  dofilewritev+0x1b6 sys/kern/sys_generic.c:365
#4  sys_write+0x83 sys/kern/sys_generic.c:285
#5  syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#5  syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
#6  Xsyscall+0x128
ddb{1}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf  9471   6398K    6786K  78643K     10665        0
            pcb    13      8K       8K  78643K        31        0
         rtable    97      3K       3K  78643K       201        0
         ifaddr    44     10K      11K  78643K        49        0
         sysctl     2      0K       0K  78643K         2        0
       counters    43     33K      33K  78643K        43        0
       ioctlops     0      0K       4K  78643K      1473        0
            iov     0      0K      12K  78643K         4        0
          mount     1      1K       1K  78643K         1        0
         vnodes  1222     77K      77K  78643K      1254        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       1K  78643K         2        0
         VM map     2      1K       1K  78643K         2        0
            sem     8      0K       0K  78643K        14        0
        dirhash    12      2K       2K  78643K        12        0
           ACPI  1824    197K     290K  78643K     13058        0
      file desc     5     13K      25K  78643K        74        0
           proc    60     63K      83K  78643K       444        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         1        0
       in_multi    39      2K       2K  78643K        42        0
    ether_multi     1      0K       0K  78643K         2        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys    19     95K      95K  78643K        19        0
           exec     0      0K       1K  78643K       211        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   115     22K      25K  78643K      1163        0
       UVM aobj     2      2K       2K  78643K         2        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
    ip6_options     0      0K       0K  78643K         8        0
            NDP     6      0K       0K  78643K        10        0
           temp    68   3844K    3908K  78643K      2131        0
         kqueue     3      4K       6K  78643K         6        0
      SYN cache     2     16K      16K  78643K         2        0
ddb{1}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp         64        6    0        2     1     0     1     1     0     8    0
plcache    128       20    0        0     1     0     1     1     0     8    0
rtpcb       80       25    0       23     1     0     1     1     0     8    0
rtentry    112       45    0        5     2     0     2     2     0     8    0
unpcb      120       33    0       23     1     0     1     1     0     8    0
syncache   264        4    0        4     1     1     0     1     0     8    0
tcpqe       32       47    0       47     1     1     0     1     0     8    0
tcpcb      544       16    0       12     1     0     1     1     0     8    0
inpcb      280       70    0       63     2     0     2     2     0     8    1
nd6         48        6    0        0     1     0     1     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       15    0        0     1     0     1     1     0     8    0
pfstkey    112       15    0        0     1     0     1     1     0     8    0
pfstate    328       15    0        0     2     0     2     2     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      188    0        4    12     0    12    12     0     8    0
art_table   32      189    0        4     2     0     2     2     0     8    0
art_node    16       44    0        8     1     0     1     1     0     8    0
sysvmsgpl   40        6    0        2     1     0     1     1     0     8    0
semupl     112        4    0        4     1     0     1     1     0     8    1
semapl     112        6    0        0     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256     1482    0       75    89     0    89    89     0     8    0
ffsino     272     1482    0       75    95     0    95    95     0     8    0
nchpl      144     1763    0      153    60     0    60    60     0     8    0
uvmvnodes   72     1558    0        0    29     0    29    29     0     8    0
vnodes     208     1558    0        0    82     0    82    82     0     8    0
namei      1024    4620    0     4620     1     0     1     1     0     8    1
percpumem   16       32    0        0     1     0     1     1     0     8    0
scxspl     192     5239    0     5239     8     1     7     7     0     8    7
plimitpl   152       15    0        7     1     0     1     1     0     8    0
sigapl     424      289    0      258     4     0     4     4     0     8    0
futexpl     56      587    0      587     1     0     1     1     0     8    1
knotepl    112       65    0       46     1     0     1     1     0     8    0
kqueuepl   144       14    0       12     1     0     1     1     0     8    0
pipelkpl    48       83    0       73     1     0     1     1     0     8    0
pipepl     120      166    0      147     1     0     1     1     0     8    0
fdescpl    496      274    0      258     3     0     3     3     0     8    0
filepl     152     1377    0     1276     6     0     6     6     0     8    2
lockfpl    104       17    0       16     1     0     1     1     0     8    0
lockfspl    48        7    0        6     1     0     1     1     0     8    0
sessionpl  112       18    0        7     1     0     1     1     0     8    0
pgrppl      48       18    0        7     1     0     1     1     0     8    0
ucredpl     96       58    0       49     1     0     1     1     0     8    0
zombiepl   144      258    0      258     1     0     1     1     0     8    1
processpl  984      289    0      258     5     0     5     5     0     8    1
procpl     624      398    0      358     4     0     4     4     0     8    0
sockpl     400      128    0      109     3     0     3     3     0     8    1
mcl12k     12288      2    0        0     1     0     1     1     0     8    0
mcl9k      9216       1    0        0     1     0     1     1     0     8    0
mcl8k      8192       1    0        0     1     0     1     1     0     8    0
mcl4k      4096       3    0        0     1     0     1     1     0     8    0
mcl2k      2048     202    0        0    25     0    25    25     0     8    0
mtagpl      80        6    0        0     1     0     1     1     0     8    0
mbufpl     256      232    0        0    14     0    14    14     0     8    0
bufpl      280     3421    0      133   235     0   235   235     0     8    0
anonpl      16    44071    0    29278    77     1    76    76     0   124   15
amapchunkpl 152    1298    0     1164     8     0     8     8     0   158    1
amappl16   192     1280    0      478    52     0    52    52     0     8   11
amappl15   184        1    0        1     1     1     0     1     0     8    0
amappl14   176       45    0       39     1     0     1     1     0     8    0
amappl13   168       72    0       67     1     0     1     1     0     8    0
amappl12   160       29    0       24     1     0     1     1     0     8    0
amappl11   152       53    0       38     1     0     1     1     0     8    0
amappl10   144       18    0       12     1     0     1     1     0     8    0
amappl9    136      383    0      382     1     0     1     1     0     8    0
amappl8    128      342    0      313     2     0     2     2     0     8    0
amappl7    120      120    0      107     1     0     1     1     0     8    0
amappl6    112       23    0       20     1     0     1     1     0     8    0
amappl5    104      157    0      142     1     0     1     1     0     8    0
amappl4     96      509    0      480     1     0     1     1     0     8    0
amappl3     88      131    0      121     1     0     1     1     0     8    0
amappl2     80     1254    0     1191     2     0     2     2     0     8    0
amappl1     72    16007    0    15579    23     6    17    18     0     8    7
amappl      80      648    0      607     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        1    0        0     1     0     1     1     0     8    0
uaddrrnd    24      274    0      258     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      274    0      258     1     0     1     1     0     8    0
vmmpekpl   168     6218    0     6188     2     0     2     2     0     8    0
vmmpepl    168    40404    0    38487   115     2   113   113     0   357   28
vmsppl     368      273    0      258     2     0     2     2     0     8    0
pdppl      4096     555    0      516     6     0     6     6     0     8    0
pvpl        32   145778    0   127936   180     0   180   180     0   265   31
pmappl     232      273    0      258     2     0     2     2     0     8    1
extentpl    40       53    0       36     1     0     1     1     0     8    0
phpool     112      262    0        3     8     0     8     8     0     8    0
ddb{1}> machine ddbcpu 0
Stopped at      x86_ipi_db+0x1a:        addq    $0x8,%rsp
x86_ipi_db(ffffffff82700ff0) 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
x86_bus_space_io_write_1(3f8,0,65) at x86_bus_space_io_write_1+0x45 sys/arch/amd64/amd64/bus_space.c:759
comcnputc(800,65) at comcnputc+0x131 bus_space_barrier machine/bus.h:481 [inline]
comcnputc(800,65) at comcnputc+0x131 sys/dev/ic/com.c:1254
cnputc(65) at cnputc+0x4c sys/dev/cons.c:239
kputchar(65,5,0) at kputchar+0x219 sys/kern/subr_prf.c:343
kprintf() at kprintf+0x15c sys/kern/subr_prf.c:700
panic(ffffffff823e71fa) at panic+0xf3 vprintf sys/kern/subr_prf.c:528 [inline]
panic(ffffffff823e71fa) at panic+0xf3 sys/kern/subr_prf.c:197
pool_cache_get(ffffffff8290ecd8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline]
pool_cache_get(ffffffff8290ecd8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884
pool_get(ffffffff8290ecd8,2) at pool_get+0x91 sys/kern/subr_pool.c:572
m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283
tcp_output(ffff800000ad7760) at tcp_output+0x14e6
tcp_usrreq(fffffd806f680640,9,fffffd806a1fdd00,0,0,ffff800020e5f600) at tcp_usrreq+0xa55
end trace frame: 0xffff800020e47270, count: 0
ddb{0}> trace
x86_ipi_db(ffffffff82700ff0) 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
x86_bus_space_io_write_1(3f8,0,65) at x86_bus_space_io_write_1+0x45 sys/arch/amd64/amd64/bus_space.c:759
comcnputc(800,65) at comcnputc+0x131 bus_space_barrier machine/bus.h:481 [inline]
comcnputc(800,65) at comcnputc+0x131 sys/dev/ic/com.c:1254
cnputc(65) at cnputc+0x4c sys/dev/cons.c:239
kputchar(65,5,0) at kputchar+0x219 sys/kern/subr_prf.c:343
kprintf() at kprintf+0x15c sys/kern/subr_prf.c:700
panic(ffffffff823e71fa) at panic+0xf3 vprintf sys/kern/subr_prf.c:528 [inline]
panic(ffffffff823e71fa) at panic+0xf3 sys/kern/subr_prf.c:197
pool_cache_get(ffffffff8290ecd8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline]
pool_cache_get(ffffffff8290ecd8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884
pool_get(ffffffff8290ecd8,2) at pool_get+0x91 sys/kern/subr_pool.c:572
m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283
tcp_output(ffff800000ad7760) at tcp_output+0x14e6
tcp_usrreq(fffffd806f680640,9,fffffd806a1fdd00,0,0,ffff800020e5f600) at tcp_usrreq+0xa55
sosend(fffffd806f680640,0,ffff800020e47338,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549
dofilewritev(ffff800020e5f600,4,ffff800020e47338,0,ffff800020e47420) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365
sys_write(ffff800020e5f600,ffff800020e473d0,ffff800020e47420) at sys_write+0x83 sys/kern/sys_generic.c:285
syscall(ffff800020e474a0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800020e474a0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffe23a0, count: -19
ddb{0}> machine ddbcpu 1
Stopped at      savectx+0xb1:   movl    $0,%gs:0x530
savectx() at savectx+0xb1
end of kernel
end trace frame: 0x7f7ffffeaa60, count: 14
ddb{1}> trace
savectx() at savectx+0xb1
end of kernel
end trace frame: 0x7f7ffffeaa60, count: -1

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/13 19:49 openbsd 2ed200e57779 dbce178a .config console log report ci-openbsd-multicore
* Struck through repros no longer work on HEAD.