syzbot


uvm_fault: uvm_unmap_remove (3)

Status: upstream: reported on 2025/12/24 01:39
Reported-by: syzbot+558f1b874b17329300b7@syzkaller.appspotmail.com
First crash: 48d, last: 3d12h
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd uvm_fault: uvm_unmap_remove (2) -1 C 7836 2259d 2342d 3/3 fixed on 2019/12/04 16:31
openbsd uvm_fault: uvm_unmap_remove -1 C 780 2342d 2361d 3/3 fixed on 2019/09/12 08:35

Sample crash report:
login: uvm_fault(0xffffffff8390c430, 0x48, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at      uvm_unmap_remove+0x426: movq    0x48(%r15),%r14
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*287770  79258      0     0x14000      0x200    0  reaper
uvm_unmap_remove(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000,ffff80002a7639c8,0,1,129ce9e1f74a439d) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff80003c9d8000,6000,ffffffff83695ae8,ffffffff83485c30) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80003c937788) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ca60) at reaper+0x1a9 sys/kern/kern_exit.c:493
end trace frame: 0x0, count: 10
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(0xffffffff8390c430, 0x48, 0, 1) -> e
ddb> trace
uvm_unmap_remove(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000,ffff80002a7639c8,0,1,129ce9e1f74a439d) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff80003c9d8000,6000,ffffffff83695ae8,ffffffff83485c30) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80003c937788) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ca60) at reaper+0x1a9 sys/kern/kern_exit.c:493
end trace frame: 0x0, count: -5
ddb> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a7639b0
rbx               0xffffffff838a47e8    kernel_map_store
rdx                                0
rcx                                0
rax               0xffff80002a72ca60
r8                                 0
r9                               0x1
r10               0xf3277684c03dae7a
r11               0x59c41226fd331edf
r12               0xffff80003c9de000
r13               0xffff80003c9d8000
r14                                0
r15                                0
rip               0xffffffff81ffb346    uvm_unmap_remove+0x426
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80002a763920
ss                              0x10
uvm_unmap_remove+0x426: movq    0x48(%r15),%r14
ddb> show proc
PROC (reaper) tid=287770 pid=79258 tcnt=1 stat=onproc
    flags process=14000<NOZOMBIE,SYSTEM> proc=200<SYSTEM>
    runpri=4, usrpri=50, slppri=4, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a72c530,0xffff80002a72cfa0
    process=0xffff8000ffffc900 user=0xffff80002a75e000, vmspace=0xffffffff8390c430
    estcpu=0, cpticks=9, pctcpu=0.0, user=0, sys=0, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 41341  383521  78245      0  3        0x80  fsleep        syz-executor
 41341  421675  78245      0  3   0x4000080  lockf         syz-executor
 26128  521521  41291      0  3        0x80  fsleep        syz-executor
 26128  116303  41291      0  3   0x4000080  pipewr        syz-executor
 41291  519138  48719      0  3        0x82  nanoslp       syz-executor
 26742   57050  46145      0  3        0x80  fsleep        syz-executor
 26742  202101  46145      0  3   0x4000080  kqread        syz-executor
 39454  452532    645     -1  3        0x90  fsleep        syz-executor
 39454  414726    645     -1  3   0x4000090  kqsel         syz-executor
 87266  160396      0      0  3     0x14200  acct          acct
 56685  369617  66446      0  3        0x80  fsleep        syz-executor
 56685  435875  66446      0  3   0x4000080  sbwait        syz-executor
 56685  188552  66446      0  3   0x4000080  fsleep        syz-executor
  5229  127316  93588      0  3        0x80  fsleep        syz-executor
  5229   39151  93588      0  3   0x4000080  piperd        syz-executor
 54129  459942      1      0  3    0x100083  ttyin         getty
 78245  119228  48719      0  3        0x82  nanoslp       syz-executor
 66446  516431  48719      0  3        0x82  nanoslp       syz-executor
 35981  119973      0      0  3     0x14280  nfsidl        nfsio
 75714  395277      0      0  3     0x14280  nfsidl        nfsio
 60752  342833      0      0  3     0x14280  nfsidl        nfsio
 50021  457710      0      0  3     0x14280  nfsidl        nfsio
 56511  174892      0      0  3     0x14280  nfsidl        nfsio
 48854  419499      0      0  3     0x14280  nfsidl        nfsio
 40787  452474      0      0  3     0x14280  nfsidl        nfsio
 70820  481994      0      0  3     0x14280  nfsidl        nfsio
 37299  348083      0      0  3     0x14280  nfsidl        nfsio
 58846  100956      0      0  3     0x14280  nfsidl        nfsio
 34241  386318      0      0  3     0x14280  nfsidl        nfsio
 23484  154337      0      0  3     0x14280  nfsidl        nfsio
 59119   93561      0      0  3     0x14280  nfsidl        nfsio
 10834  204425      0      0  3     0x14280  nfsidl        nfsio
  9076  187738      0      0  3     0x14280  nfsidl        nfsio
 22515   96678      0      0  3     0x14280  nfsidl        nfsio
 10275  184467      0      0  3     0x14280  nfsidl        nfsio
 39267  369883      0      0  3     0x14280  nfsidl        nfsio
 44684  314646      0      0  3     0x14280  nfsidl        nfsio
 41677   41378      0      0  3     0x14280  nfsidl        nfsio
   645  398504  48719      0  2       0xc82                syz-executor
 30525  503130  48719      0  3        0x82  nanoslp       syz-executor
 37155  273507  48719      0  3        0x82  wait          syz-executor
 93588  430301  48719      0  2       0xc82                syz-executor
 46145  221483  48719      0  2       0xc82                syz-executor
 48719  369425   2312      0  3        0x82  kqread        syz-executor
  2312  459915  94981      0  3    0x10008a  sigsusp       ksh
 94981  343560   9027      0  3        0x98  kqread        sshd-session
  9027  241848  35326      0  3        0x92  kqread        sshd-session
 35326   21150      1      0  3        0x88  kqread        sshd
  7744   20005  41990     73  3   0x1100090  kqread        syslogd
 41990  509494      1      0  3    0x100082  sbwait        syslogd
 68127  399617      1      0  3    0x100080  kqread        resolvd
 84523  183968  76670     77  3    0x100092  kqread        dhcpleased
 71950  210909  76670     77  3    0x100092  kqread        dhcpleased
 76670  212256      1      0  3        0x80  kqread        dhcpleased
 67524  295063      0      0  3     0x14200  bored         smr
 89605  233381      0      0  3     0x14200  pgzero        zerothread
 35819  238963      0      0  3     0x14200  aiodoned      aiodoned
 97454  230691      0      0  3     0x14200  syncer        update
 16693  458594      0      0  3     0x14200  cleaner       cleaner
*79258  287770      0      0  7     0x14200                reaper
 61048  315447      0      0  3     0x14200  pgdaemon      pagedaemon
 53862  511695      0      0  3     0x14200  bored         viomb
 67266  178090      0      0  3  0x40014200  acpi0         acpi0
 42917  299930      0      0  3     0x14200  bored         softnet0
 23164   99189      0      0  3     0x14200  bored         systqmp
 28411  497733      0      0  3     0x14200  bored         systq
  4616  225644      0      0  3  0x40014200  tmoslp        softclock
 11997   35723      0      0  3  0x40014200                idle0
     1  439290      0      0  3        0x82  wait          init
     0       0     -1      0  3  0x10010200  scheduler     swapper
ddb> show all locks
No such command
ddb> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11067  12119K   13224K 166960K     14384        0
            pcb    18     14K      16K 166960K       296        0
         rtable   213      9K      10K 166960K       605        0
             pf    31     13K      14K 166960K       110        0
         ifaddr    36      6K       8K 166960K        94        0
        ifgroup    50      2K       2K 166960K       142        0
         sysctl     4      1K       9K 166960K        11        0
       counters    33     17K      18K 166960K        75        0
       ioctlops     0      0K       4K 166960K       291        0
            iov     0      0K      24K 166960K        49        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1456     91K      92K 166960K      2328        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K      13K 166960K        12        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K        20        0
        dirhash    12      2K       2K 166960K        27        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    18     65K      97K 166960K      1047        0
          sigio     0      0K       0K 166960K        21        0
           proc    60     59K     108K 166960K       651        0
        subproc    72      4K       4K 166960K       101        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K       108        0
       in_multi    77      5K       7K 166960K       172        0
    ether_multi     1      0K       0K 166960K        11        0
            mrt     1      0K       0K 166960K         6        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   229   1023K    1023K 166960K       229        0
           exec     0      0K       1K 166960K       453        0
   fusefs mount     1     32K      32K 166960K         1        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   230    159K     173K 166960K     10673        0
       UVM aobj    22     10K      10K 166960K        28        0
     pinsyscall    39     78K      94K 166960K      2224        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       1K 166960K        43        0
            NDP    13      0K       2K 166960K        63        0
           temp    81   8676K    8744K 166960K     30214        0
         kqueue    16     22K      31K 166960K       185        0
      SYN cache     2     16K      16K 166960K         2        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
rtpcb      120      100    0       97     1     0     1     1     0     8    0
rtentry    136      161    0       80     4     0     4     4     0     8    0
unpcb      144      452    0      434     3     1     2     2     0     8    1
syncache   336        4    0        4     2     1     1     1     0     8    1
tcpcb      736      362    0      358    13     6     7     7     0     8    6
arp         96       25    0        8     1     0     1     1     0     8    0
ipq         40        6    0        4     1     0     1     1     0     8    0
ipqe        40       11    0        9     1     0     1     1     0     8    0
inpcb      328     1065    0     1057    13     6     7     7     0     8    6
ip6q        72        2    0        1     1     0     1     1     0     8    0
ip6af       40        3    0        2     1     0     1     1     0     8    0
nd6        112       38    0       19     1     0     1     1     0     8    0
pkpcb       40        6    0        6     2     1     1     1     0     8    1
kcovpl      48       11    0        3     1     0     1     1     0     8    0
ppxss      1072      31    0       31     2     1     1     1     0     8    1
pppxif     1384       3    0        3     1     0     1     1     0     8    1
pfrktable  1344       1    0        0     1     0     1     1     0     8    0
pftag       88        1    0        0     1     0     1     1     0     8    0
pfrule     1360       3    0        2     1     0     1     1     0     8    0
art_heap8  4096       5    0        0     5     0     5     5     0     8    0
art_heap4  256      709    0      367    32     3    29    32     0     8    7
art_table   40      714    0      367     6     0     6     6     0     8    0
art_node    32      160    0       87     1     0     1     1     0     8    0
sysvmsgpl   40       36    0       35     2     1     1     1     0     8    0
semapl     112       18    0        8     1     0     1     1     0     8    0
shmpl      112       22    0        5     1     0     1     1     0     8    0
dirhash    1024      27    0       10     3     0     3     3     0     8    0
dino2pl    256     3266    0     1769    95     0    95    95     0     8    0
ffsino     256     3266    0     1769    95     0    95    95     0     8    0
nchpl      144     4693    0     2996    64     0    64    64     0     8    0
rtmask      32        4    0        4     2     1     1     1     0     8    1
vnodes     216     3956    0        0   220     0   220   220     0     8    0
namei      1024   15542    0    15542     3     2     1     2     0     8    1
vcpupl     3904       3    0        1     1     0     1     1     0     8    0
vmpool     808        3    0        1     1     0     1     1     0     8    0
kstatmem   264       82    0       60     2     0     2     2     0     8    0
acpiwqpl    32        1    0        1     1     0     1     1     1     8    1
scsiplug    72        6    0        6     2     1     1     1     0     8    1
scxspl     216    20796    0    20796    10     2     8     8     1     8    8
plimitpl   152      164    0      145     1     0     1     1     0     8    0
sigapl     424     1358    0     1294     8     0     8     8     0     8    0
knotepl    120    57724    0    57670    47    35    12    17     0     8    8
kqueuepl   184      277    0      265     1     0     1     1     0     8    0
pipepl     304      257    0      228     8     0     8     8     0     8    5
fdescpl    448     1322    0     1292     5     1     4     5     0     8    0
filepl     120     7365    0     7142    13     2    11    11     0     8    3
lockfpl    104      291    0      286     1     0     1     1     0     8    0
lockfspl    48      119    0      115     1     0     1     1     0     8    0
sessionpl  144       29    0       21     1     0     1     1     0     8    0
pgrppl      48       51    0       35     1     0     1     1     0     8    0
ucredpl    104     1018    0     1005     1     0     1     1     0     8    0
zombiepl   144     1536    0     1534     1     0     1     1     0     8    0
processpl  1152    1358    0     1294     5     0     5     5     0     8    0
procpl     664     2672    0     2600     7     0     7     7     0     8    0
sosppl     176        8    0        8     2     1     1     1     0     8    1
sockpl     552     1698    0     1669    12     5     7     8     0     8    4
mcl64k     65536    120    0      120     1     0     1     1     0     8    1
mcl16k     16384      1    0        1     1     0     1     1     0     8    1
mcl12k     12288      2    0        2     2     1     1     1     0     8    1
mcl8k      8192      25    0       25     1     0     1     1     0     8    1
mcl4k      4096    3629    0     3575    16     8     8    16     0     8    1
mcl2k2     2112       2    0        2     2     1     1     1     0     8    1
mcl2k      2048    1268    0     1264     8     4     4     5     0     8    3
mtagpl      96       29    0       18     1     0     1     1     0     8    0
mbufpl     256    15011    0    14856    27    10    17    26     0     8    0
bufpl      280     7471    0     1250   445     0   445   445     0     8    0
anonpl      24   195459    0   192245    54     9    45    45     0   187   17
amapchunkpl 152   36025    0    35534    42     8    34    34     0   158   14
amappl16   200     3655    0     3620    25    11    14    15     0     8    8
amappl15   192       23    0       23     1     1     0     1     0     8    0
amappl14   184        4    0        4     1     1     0     1     0     8    0
amappl13   176      443    0      442     1     0     1     1     0     8    0
amappl12   168     1728    0     1689     2     0     2     2     0     8    0
amappl11   160        5    0        4     1     0     1     1     0     8    0
amappl10   152       62    0       52     1     0     1     1     0     8    0
amappl9    144      270    0      270     1     1     0     1     0     8    0
amappl8    136       24    0       23     1     0     1     1     0     8    0
amappl7    128       94    0       93     1     0     1     1     0     8    0
amappl6    120      306    0      294     1     0     1     1     0     8    0
amappl5    112       72    0       64     1     0     1     1     0     8    0
amappl4    104      407    0      383     1     0     1     1     0     8    0
amappl3     96     6322    0     6227     3     0     3     3     0     8    0
amappl2     88     1440    0     1368     2     0     2     2     0     8    0
amappl1     80    13313    0    12765    14     1    13    13     0     8    0
amappl      88     9770    0     9609     4     0     4     4     0    92    0
uvmvnodes   80      123    0        0     3     0     3     3     0     8    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma1024    1024       2    0        1     1     0     1     1     0     8    0
dma256     256        6    0        6     1     1     0     1     0     8    0
dma128     128      259    0      259     2     1     1     1     0     8    1
dma64       64        7    0        7     2     1     1     1     0     8    1
dma32       32        7    0        7     1     1     0     1     0     8    0
dma16       16       19    0       18     1     0     1     1     0     8    0
aobjpl      72       27    0        6     1     0     1     1     0     8    0
uaddrrnd    24     1322    0     1292     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1322    0     1292     1     0     1     1     0     8    0
vmmpekpl   168    11614    0    11577     3     0     3     3     0     8    0
vmmpekpl: pool(0xffffffff838b6638:vmmpekpl): page inconsistency: page 0x0; at page head addr 0xfffffd806c0b8f90 (p 0xfffffd806c0b8000)
vmmpepl    168    88678    0    86831    93     2    91    91     0   357    5
vmsppl     368     1321    0     1292     4     1     3     4     0     8    0
rwobjpl     40    24679    0    23687    13     0    13    13     0     8    0
pdppl      4096    2656    0     2588   111    42    69    82     0     8    1
pvpl        32   562836    0   552835   136    20   116   116     0   265   29
pmappl     216     1324    0     1293     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      427    0       80    11     0    11    11     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
uvm_unmap_remove(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000,ffff80002a7639c8,0,1,129ce9e1f74a439d) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff80003c9d8000,6000,ffffffff83695ae8,ffffffff83485c30) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80003c937788) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ca60) at reaper+0x1a9 sys/kern/kern_exit.c:493
end trace frame: 0x0, count: -5
ddb> machine ddbcpu 1
No such command
ddb> trace
uvm_unmap_remove(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000,ffff80002a7639c8,0,1,129ce9e1f74a439d) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff838a47e8,ffff80003c9d8000,ffff80003c9de000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff80003c9d8000,6000,ffffffff83695ae8,ffffffff83485c30) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80003c937788) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ca60) at reaper+0x1a9 sys/kern/kern_exit.c:493
end trace frame: 0x0, count: -5

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/06 15:39 openbsd fb820f9a8913 018ebef2 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: uvm_unmap_remove
2025/12/24 01:38 openbsd 2a2497efc5fa 5dc09de1 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: uvm_unmap_remove
* Struck through repros no longer work on HEAD.