syzbot


uvm_fault: km_free

Status: auto-obsoleted due to no activity on 2022/10/10 22:33
Reported-by: syzbot+654ab682493c0c3be51e@syzkaller.appspotmail.com
First crash: 841d, last: 653d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd uvm_fault: km_free (2) 6 13d 140d 0/3 upstream: reported on 2023/12/07 19:27

Sample crash report:
login: uvm_fault(0xffffffff82a5e918, 0x0, 0, 2) -> e
kernel: page fault trap, code=0
Stopped at      km_free+0x118:  movq    $0,0(%rax)
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*173071   6913      0     0x14000      0x200    0  systqmp
km_free(0,1000,ffffffff827df828,ffffffff827df840) at km_free+0x118 sys/uvm/uvm_km.c:867
pool_p_free(ffffffff82ac4ad8,fffffd8059feaf90) at pool_p_free+0x14b sys/kern/subr_pool.c:1014
pool_gc_pages(0) at pool_gc_pages+0x215 sys/kern/subr_pool.c:1585
taskq_thread(ffffffff8290e940) at taskq_thread+0x9b sys/kern/kern_task.c:449
end trace frame: 0x0, count: 11
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: uvm_fault(0xffffffff82a5e918, 0x0, 0, 2) -> e
ddb> trace
km_free(0,1000,ffffffff827df828,ffffffff827df840) at km_free+0x118 sys/uvm/uvm_km.c:867
pool_p_free(ffffffff82ac4ad8,fffffd8059feaf90) at pool_p_free+0x14b sys/kern/subr_pool.c:1014
pool_gc_pages(0) at pool_gc_pages+0x215 sys/kern/subr_pool.c:1585
taskq_thread(ffffffff8290e940) at taskq_thread+0x9b sys/kern/kern_task.c:449
end trace frame: 0x0, count: -4
ddb> show registers
rdi                           0x1000    __ALIGN_SIZE
rsi                       0x28000000
rbp               0xffff80002168ff50
rbx                    0x28000000000
rdx                                0
rcx               0xffffffff827df840    kp_dirty
rax                                0
r8                                 0
r9                               0x1
r10               0x4981421bb66c916d
r11               0xe4f039c8a59b0b89
r12                                0
r13               0xffffffff827df828    kv_page
r14                           0x1000    __ALIGN_SIZE
r15                           0x1000    __ALIGN_SIZE
rip               0xffffffff81b2fba8    km_free+0x118
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80002168fed0
ss                              0x10
km_free+0x118:  movq    $0,0(%rax)
ddb> show proc
PROC (systqmp) pid=173071 stat=onproc
    flags process=14000<NOZOMBIE,SYSTEM> proc=200<SYSTEM>
    pri=32, usrpri=50, nice=20
    forw=0xffffffffffffffff, list=0xffff8000fffff500,0xffff8000ffffefd0
    process=0xffff8000ffffcbb8 user=0xffff80002168b000, vmspace=0xffffffff82a5e918
    estcpu=0, cpticks=0, pctcpu=0.0
    user=0, sys=0, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 86324  135588      1      0  3    0x100083  ttyin         getty
 79329   79577  41701      0  3        0x82  piperd        syz-executor.4
 94402   32441  41701      0  3        0x82  piperd        syz-executor.5
 76730   36607  41701      0  3        0x82  piperd        syz-executor.6
 81439  370005  41701      0  3        0x82  piperd        syz-executor.1
 23023  227822      0      0  3     0x14200  acct          acct
 71296   80023  41701      0  3        0x82  piperd        syz-executor.0
 97713  129813  41701      0  3        0x82  nanoslp       syz-executor.3
  6786  433313  41701      0  3        0x82  piperd        syz-executor.2
 29408   71127  41701      0  3        0x82  piperd        syz-executor.7
 66555  293456      0      0  3     0x14200  bored         sosplice
 41701  429502  94218      0  3        0x82  thrsleep      syz-fuzzer
 41701  352316  94218      0  3   0x4000082  thrsleep      syz-fuzzer
 41701  329772  94218      0  3   0x4000082  kqread        syz-fuzzer
 41701   42453  94218      0  3   0x4000082  thrsleep      syz-fuzzer
 41701  144328  94218      0  3   0x4000082  thrsleep      syz-fuzzer
 41701  510827  94218      0  3   0x4000082  thrsleep      syz-fuzzer
 41701   94586  94218      0  3   0x4000082  thrsleep      syz-fuzzer
 41701  381414  94218      0  3   0x4000082  thrsleep      syz-fuzzer
 94218  179091  80729      0  3    0x10008a  sigsusp       ksh
 80729  117005   2797      0  3        0x9a  kqread        sshd
  2797  339392      1      0  3        0x88  kqread        sshd
 57602  457502  91393     73  3   0x1100090  kqread        syslogd
 91393  105491      1      0  3    0x100082  netio         syslogd
 26880  213783      1      0  3    0x100080  kqread        resolvd
  6328  185520  68693     77  3    0x100092  kqread        dhcpleased
 50729  224693  68693     77  3    0x100092  kqread        dhcpleased
 68693  131404      1      0  3        0x80  kqread        dhcpleased
 36334  305231      0      0  3     0x14200  bored         smr
 39877  132782      0      0  3     0x14200  pgzero        zerothread
 52302  429758      0      0  3     0x14200  aiodoned      aiodoned
 65032  413128      0      0  3     0x14200  syncer        update
 67874  250601      0      0  3     0x14200  cleaner       cleaner
 14312  298842      0      0  3     0x14200  reaper        reaper
 20965   57398      0      0  3     0x14200  pgdaemon      pagedaemon
 16998  322326      0      0  3     0x14200  bored         viomb
 17628   79279      0      0  3  0x40014200  acpi0         acpi0
 70059  337244      0      0  3     0x14200  bored         softnet
 33358  208291      0      0  3     0x14200  bored         softnet
 67866  124233      0      0  3     0x14200  bored         softnet
 83956  250190      0      0  3     0x14200  bored         softnet
* 6913  173071      0      0  7     0x14200                systqmp
 94134   43661      0      0  3     0x14200  bored         systq
 34101   60760      0      0  3  0x40014200  bored         softclock
 14794  383953      0      0  3  0x40014200                idle0
     1  502041      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 10207   6426K    7181K  78643K     23392        0
            pcb    13     14K      16K  78643K      1589        0
         rtable   168     14K      19K  78643K      2340        0
         ifaddr    75     17K      19K  78643K       851        0
         sysctl     2      0K       2K  78643K         5        0
       counters    26     17K      17K  78643K       136        0
       ioctlops     0      0K       8K  78643K      1968        0
            iov     0      0K      32K  78643K      1109        0
          mount     1      1K       1K  78643K         1        0
            log     0      0K       0K  78643K         4        0
         vnodes  1413     88K      88K  78643K      7034        0
      UFS quota     1     32K      32K  78643K         1        0
      UFS mount     5     36K      36K  78643K         5        0
            shm     2      1K       9K  78643K        98        0
         VM map     2      0K       0K  78643K         2        0
            sem    12      0K       0K  78643K       577        0
        dirhash    12      2K       2K  78643K        12        0
           ACPI  1697    195K     286K  78643K     12548        0
      file desc    11     37K      81K  78643K      8660        0
          sigio     0      0K       0K  78643K       239        0
           proc    58     59K      75K  78643K      1991        0
        subproc   104      6K       7K  78643K       611        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
    ip_moptions     0      0K       0K  78643K       676        0
       in_multi    68      4K       6K  78643K       761        0
    ether_multi     1      0K       0K  78643K        22        0
            mrt     1      0K       0K  78643K        49        0
    ISOFS mount     1     32K      32K  78643K         1        0
  MSDOSFS mount     1     16K      16K  78643K         1        0
           ttys   217    970K     970K  78643K       217        0
           exec     0      0K       2K  78643K      2859        0
     pfkey data     0      0K       0K  78643K        36        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   424   1099K    1100K  78643K     50068        0
       UVM aobj   131      4K       4K  78643K       131        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
    ip6_options     0      0K       0K  78643K       203        0
            NDP    11      0K       2K  78643K       234        0
           temp   159   4772K    6782K  78643K    201539        0
         kqueue    12     18K      26K  78643K       717        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      711    0      708    11    10     1     5     0     8    0
rtentry    112      682    0      613     4     0     4     4     0     8    0
unpcb      144    20052    0    20039   257   254     3    11     0     8    2
syncache   296       62    0       62    16    16     0     1     0     8    0
tcpqe       32       51    0       51     4     4     0     1     0     8    0
tcpcb      736     3173    0     3169   194   189     5    14     0     8    4
arp         88      102    0       92     1     0     1     1     0     8    0
ipq         40        2    0        2     2     2     0     1     0     8    0
ipqe        40        7    0        7     2     2     0     1     0     8    0
inpcb      320     6937    0     6930   236   232     4    12     0     8    3
ip6q        72        9    0        9     3     3     0     1     0     8    0
ip6af       40       16    0       16     3     3     0     1     0     8    0
nd6         48      175    0      157     1     0     1     1     0     8    0
pkpcb       40       20    0       20     5     5     0     1     0     8    0
kcovpl      48       47    0       39     1     0     1     1     0     8    0
ppxss      1160      35    0       35    11    11     0     1     0     8    0
pfrktable  1344      75    0       73     3     2     1     1     0     8    0
pftag       88       12    0        6     1     0     1     1     0     8    0
pfrule     1360     108    0      104     5     4     1     2     0     8    0
rttmr      136       15    0       15     5     5     0     1     0     8    0
art_heap8  4096       2    0        1     2     1     1     2     0     8    0
art_heap4  256     3001    0     2642    56    29    27    29     0     8    0
art_table   32     3003    0     2643     4     0     4     4     0     8    0
art_node    16      667    0      607     1     0     1     1     0     8    0
sysvmsgpl   40      104    0       95     3     2     1     1     0     8    0
semapl     112      575    0      565     1     0     1     1     0     8    0
shmpl      112      128    0        0     4     0     4     4     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256    13983    0    12538    92     1    91    91     0     8    0
ffsino     240    13983    0    12538    86     0    86    86     0     8    0
nchpl      144    25680    0    24042    63     0    63    63     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  100109    0   100109    25    24     1     2     0     8    1
vcpupl     2048      72    0        1     9     0     9     9     0     8    0
vmpool     536      164    0       93     6     1     5     5     0     8    0
pfiaddrpl  120       33    0       29     3     2     1     1     0     8    0
kstatmem   264      242    0      220     2     0     2     2     0     8    0
scsiplug    72       30    0       30     7     7     0     1     0     8    0
scxspl     216    84034    0    84034    33    32     1     8     0     8    1
plimitpl   152     1692    0     1678     1     0     1     1     0     8    0
sigapl     424     8893    0     8853     8     2     6     8     0     8    0
futexpl     64    83526    0    83526    27    26     1     1     0     8    1
knotepl    120   138137    0   138055    75    69     6    11     0     8    0
kqueuepl   184     1869    0     1861    29    28     1     4     0     8    0
pipepl     288     1510    0     1482    29    26     3     7     0     8    0
fdescpl    432     8853    0     8831     4     0     4     4     0     8    0
filepl     120    74967    0    74730   252   239    13    17     0     8    4
lockfpl    104     2405    0     2403     6     5     1     2     0     8    0
lockfspl    48      642    0      640     1     0     1     1     0     8    0
sessionpl  144       65    0       49     1     0     1     1     0     8    0
pgrppl      48      112    0       96     1     0     1     1     0     8    0
ucredpl    104    14162    0    14150     1     0     1     1     0     8    0
zombiepl   144     8854    0     8853     2     1     1     1     0     8    0
processpl  1000    8893    0     8853    13     6     7     9     0     8    0
procpl     672    23910    0    23863    26    18     8     9     0     8    0
sosppl     168       84    0       84    22    22     0     1     0     8    0
sockpl     456    27724    0    27701  1046  1038     8    42     0     8    5
mcl64k     65536    294    0      294    64    63     1     1     0     8    1
mcl16k     16384     66    0       66    29    29     0     1     0     8    0
mcl12k     12288    257    0      257    55    54     1     1     0     8    1
mcl9k      9216     101    0      101    39    39     0     1     0     8    0
mcl8k      8192     570    0      570    72    71     1     1     0     8    1
mcl4k      4096     979    0      979    54    53     1     3     0     8    1
mcl2k2     2112      55    0       55    38    38     0     1     0     8    0
mcl2k      2048   87768    0    87694    34    24    10    19     0     8    0
mtagpl      96     1611    0     1492    24    21     3    19     0     8    0
mbufpl     256   196835    0   196532   509   487    22   418     0     8    0
bufpl      288    20354    0    13953   458     0   458   458     0     8    0
anonpl      24  1812491    0  1790959   377   237   140   156     0   188    0
amapchunkpl 152  159726    0   158947   148   113    35    43     0   158    2
amappl16   200    26039    0    25296   177   135    42    53     0     8    0
amappl15   192     2445    0     2440     1     0     1     1     0     8    0
amappl14   184     1655    0     1650     1     0     1     1     0     8    0
amappl13   176      962    0      958     1     0     1     1     0     8    0
amappl12   168      976    0      973     1     0     1     1     0     8    0
amappl11   160      703    0      685     1     0     1     1     0     8    0
amappl10   152     1170    0     1166     1     0     1     1     0     8    0
amappl9    144     1300    0     1296     1     0     1     1     0     8    0
amappl8    136     2825    0     2740     6     2     4     4     0     8    0
amappl7    128     1767    0     1755     1     0     1     1     0     8    0
amappl6    120     1251    0     1232     2     1     1     2     0     8    0
amappl5    112     7335    0     7324     1     0     1     1     0     8    0
amappl4    104     4075    0     4046     2     1     1     2     0     8    0
amappl3     96    26126    0    26084     2     0     2     2     0     8    0
amappl2     88    10520    0    10455     3     1     2     3     0     8    0
amappl1     80   211154    0   210613    22     7    15    19     0     8    0
amappl      88    48613    0    48420     8     2     6     6     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     9017    0     8924     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     9017    0     8924     1     0     1     1     0     8    0
vmmpekpl   168    67098    0    67030     4     0     4     4     0     8    0
vmmpepl    168   874316    0   871940   404   270   134   144     0   357    0
vmsppl     272     9016    0     8924    13     6     7     7     0     8    0
rwobjpl     24   218264    0   210464    54     4    50    50     0     8    0
pdppl      4096   18040    0    17919  1213  1078   135   135     0     8   14
pvpl        32  3831808    0  3811782   676   489   187   255     0   265    0
pmappl     216     9016    0     8924     7     1     6     6     0     8    0
extentpl    40       58    0       38     1     0     1     1     0     8    0
phpool     112     2950    0     2087    36    10    26    29     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
km_free(0,1000,ffffffff827df828,ffffffff827df840) at km_free+0x118 sys/uvm/uvm_km.c:867
pool_p_free(ffffffff82ac4ad8,fffffd8059feaf90) at pool_p_free+0x14b sys/kern/subr_pool.c:1014
pool_gc_pages(0) at pool_gc_pages+0x215 sys/kern/subr_pool.c:1585
taskq_thread(ffffffff8290e940) at taskq_thread+0x9b sys/kern/kern_task.c:449
end trace frame: 0x0, count: -4
ddb> machine ddbcpu 1
No such command
ddb> trace
km_free(0,1000,ffffffff827df828,ffffffff827df840) at km_free+0x118 sys/uvm/uvm_km.c:867
pool_p_free(ffffffff82ac4ad8,fffffd8059feaf90) at pool_p_free+0x14b sys/kern/subr_pool.c:1014
pool_gc_pages(0) at pool_gc_pages+0x215 sys/kern/subr_pool.c:1585
taskq_thread(ffffffff8290e940) at taskq_thread+0x9b sys/kern/kern_task.c:449
end trace frame: 0x0, count: -4

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/07/12 22:33 openbsd bf955257b2e4 d91dd8ea .config console log report ci-openbsd-main uvm_fault: km_free
2022/06/07 16:04 openbsd 39be06a3852c b2706118 .config console log report ci-openbsd-multicore uvm_fault: km_free
2022/05/10 15:41 openbsd 05b87ca2e5c9 8d7b3b67 .config console log report ci-openbsd-main uvm_fault: km_free
2022/04/21 15:02 openbsd 7b7e933f4f8f 2738b391 .config console log report ci-openbsd-main uvm_fault: km_free
2022/03/13 00:18 openbsd 447db83cf4f0 9e8eaa75 .config console log report ci-openbsd-multicore uvm_fault: km_free
2022/01/05 18:37 openbsd bce33954026f 6acc789a .config console log report ci-openbsd-multicore uvm_fault: km_free
* Struck through repros no longer work on HEAD.