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: 1d11h, last: 1d11h
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 2212d 2296d 3/3 fixed on 2019/12/04 16:31
openbsd uvm_fault: uvm_unmap_remove -1 C 780 2296d 2315d 3/3 fixed on 2019/09/12 08:35

Sample crash report:
uvm_fault(0xffffffff838a83f8, 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
*523770  17955      0     0x14000      0x200    0  reaper
uvm_unmap_remove(ffffffff8391e288,ffff800033cfe000,ffff800033d04000,ffff80002a763b98,0,1,486591a487765a35) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff800033cfe000,6000,ffffffff83491068,ffffffff835724f8) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80002a776f98) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ccf8) 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(0xffffffff838a83f8, 0x48, 0, 1) -> e
ddb> trace
uvm_unmap_remove(ffffffff8391e288,ffff800033cfe000,ffff800033d04000,ffff80002a763b98,0,1,486591a487765a35) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff800033cfe000,6000,ffffffff83491068,ffffffff835724f8) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80002a776f98) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ccf8) at reaper+0x1a9 sys/kern/kern_exit.c:493
end trace frame: 0x0, count: -5
ddb> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a763b80
rbx               0xffffffff8391e288    kernel_map_store
rdx                                0
rcx                                0
rax               0xffff80002a72ccf8
r8                                 0
r9                               0x1
r10               0x16996222c634ddbd
r11               0x9d3d1be16e6d60cc
r12               0xffff800033d04000
r13               0xffff800033cfe000
r14                                0
r15                                0
rip               0xffffffff82e73ea6    uvm_unmap_remove+0x426
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80002a763af0
ss                              0x10
uvm_unmap_remove+0x426: movq    0x48(%r15),%r14
ddb> show proc
PROC (reaper) tid=523770 pid=17955 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=0xffff80002a72ca60,0xffff80002a72cfa0
    process=0xffff8000ffffd680 user=0xffff80002a75e000, vmspace=0xffffffff838a83f8
    estcpu=0, cpticks=13, pctcpu=0.0, user=0, sys=0, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 52410  477097  83642      0  2           0                syz-executor
 52410  370755  83642      0  3   0x4000080  msgwait       syz-executor
 52410  326493  83642      0  2   0x4000000                syz-executor
  6568  165771  66214      0  2      0x3000                syz-executor
 16426  307305  92914      0  2    0x100002                sh
 92914  377252  32286      0  3        0x82  wait          syz-executor
 58431  102853   5699     -1  3        0x90  nanoslp       syz-executor
 58431  308560   5699     -1  3   0x4000090  lockf         syz-executor
 58431   51397   5699     -1  3   0x4000090  fsleep        syz-executor
 19433  470896  32286      0  3        0x82  wait          syz-executor
  5699   48372  32286      0  3        0x82  nanoslp       syz-executor
 31301  308201      0      0  3     0x14280  nfsidl        nfsio
 63163    7490      1      0  3    0x100083  ttyin         getty
 23535  438073  32286      0  3        0x82  piperd        syz-executor
 66214   77673  32286      0  3        0x82  nanoslp       syz-executor
 83642  188818  32286      0  3        0x82  nanoslp       syz-executor
 93099  405008  32286      0  3        0x82  wait          syz-executor
 85100  142702  32286      0  3        0x82  piperd        syz-executor
 32286  175541  88255      0  2         0x2                syz-executor
 88255  477192  66857      0  3    0x10008a  sigsusp       ksh
 66857  103919  43160      0  3        0x98  kqread        sshd-session
 43160  382104  38385      0  3        0x92  kqread        sshd-session
 38385  434344      1      0  3        0x88  kqread        sshd
   589  240056  58221     73  3   0x1100090  kqread        syslogd
 58221  137859      1      0  3    0x100082  sbwait        syslogd
 35377   77450      1      0  3    0x100080  kqread        resolvd
 34538  192957  19871     77  3    0x100092  kqread        dhcpleased
   962   61071  19871     77  3    0x100092  kqread        dhcpleased
 19871  303298      1      0  3        0x80  kqread        dhcpleased
 28391  495446      0      0  3     0x14200  bored         smr
 69491   88144      0      0  2     0x14200                zerothread
 28551  228343      0      0  3     0x14200  aiodoned      aiodoned
 39675  394705      0      0  3     0x14200  syncer        update
 32398  260051      0      0  3     0x14200  cleaner       cleaner
*17955  523770      0      0  7     0x14200                reaper
 10690  120995      0      0  3     0x14200  pgdaemon      pagedaemon
 86026  309482      0      0  3     0x14200  bored         viomb
 97829  482604      0      0  3  0x40014200  acpi0         acpi0
 49030   59188      0      0  3     0x14200  bored         softnet0
 63363  397576      0      0  3     0x14200  bored         systqmp
 54117  515829      0      0  3     0x14200  bored         systq
  2531  420383      0      0  3  0x40014200  tmoslp        softclock
 37788   59444      0      0  3  0x40014200                idle0
     1  306462      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 11049  12180K   13432K 166960K     15356        0
            pcb    17     15K      17K 166960K       524        0
         rtable   188     10K      11K 166960K       722        0
             pf    33     13K      16K 166960K       155        0
         ifaddr    32      5K       7K 166960K       112        0
        ifgroup    50      2K       2K 166960K       177        0
         sysctl     4      1K       9K 166960K        18        0
       counters    33     17K      18K 166960K       100        0
       ioctlops     0      0K       4K 166960K       302        0
            iov     0      0K      16K 166960K        86        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1498     94K      95K 166960K      3048        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K      13K 166960K        28        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       1K 166960K        48        0
        dirhash    12      2K       2K 166960K        48        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    16     57K     240K 166960K      1620        0
          sigio     0      0K       0K 166960K        21        0
           proc    61     59K     108K 166960K       763        0
        subproc    72      4K       4K 166960K       108        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K       226        0
       in_multi    56      4K       6K 166960K       178        0
    ether_multi     1      0K       0K 166960K        11        0
            mrt     1      0K       0K 166960K        13        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    91    413K     413K 166960K        91        0
           exec     0      0K       1K 166960K       623        0
   fusefs mount     1     32K      32K 166960K         1        0
     pfkey data     0      0K       0K 166960K         4        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   219    144K     160K 166960K     15843        0
       UVM aobj    71      7K       8K 166960K        76        0
     pinsyscall    37     74K      94K 166960K      2815        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       1K 166960K        81        0
            NDP    11      0K       1K 166960K        75        0
           temp    75   8672K    8799K 166960K     78325        0
         kqueue    13     20K      31K 166960K       340        0
      SYN cache     2      0K      16K 166960K         4        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
rtpcb      120      314    0      311     3     2     1     3     0     8    0
rtentry    136      189    0      127     4     0     4     4     0     8    0
unpcb      144     1486    0     1470    10     9     1    10     0     8    0
syncache   336       18    0       18     3     2     1     1     0     8    1
tcpqe       32       13    0       13     3     2     1     1     0     8    1
tcpcb      736      565    0      553     7     5     2     7     0     8    0
arp         96       29    0       18     1     0     1     1     0     8    0
ipq         40       12    0        2     1     0     1     1     0     8    0
ipqe        40       14    0        4     1     0     1     1     0     8    0
inpcb      328     1734    0     1718     7     4     3     7     0     8    0
ip6q        72        5    0        4     1     0     1     1     0     8    0
ip6af       40        9    0        8     1     0     1     1     0     8    0
nd6        112       38    0       24     1     0     1     1     0     8    0
pkpcb       40        7    0        7     2     2     0     1     0     8    0
kcovpl      48       12    0        4     1     0     1     1     0     8    0
mppekey    1024       2    0        2     1     1     0     1     0     8    0
ppxss      1072      51    0       51     1     0     1     1     0     8    1
pppxif     1384      10    0       10     2     1     1     1     0     8    1
pfstscr     40        2    0        2     1     1     0     1     0     8    0
pfrktable  1344       6    0        3     1     0     1     1     0     8    0
pfanchor   1288       1    0        0     1     0     1     1     0     8    0
pftag       88        2    0        0     1     0     1     1     0     8    0
pfstitem    24        2    0        0     1     0     1     1     0     8    0
pfstkey    128        4    0        2     1     0     1     1     0     8    0
pfstate    384        2    0        1     1     0     1     1     0     8    0
pfrule     1344       5    0        4     1     0     1     1     0     8    0
rttmr      136        2    0        2     1     1     0     1     0     8    0
art_heap8  4096       5    0        1     5     1     4     5     0     8    0
art_heap4  256      839    0      559    26     4    22    26     0     8    0
art_table   40      844    0      560     5     0     5     5     0     8    0
art_node    32      186    0      132     1     0     1     1     0     8    0
sysvmsgpl   40       11    0        6     1     0     1     1     0     8    0
semupl     112        4    0        4     1     1     0     1     0     8    0
semapl     112       43    0       33     1     0     1     1     0     8    0
shmpl      112       71    0        4     2     0     2     2     0     8    0
dirhash    1024      41    0       24     3     0     3     3     0     8    0
dino2pl    256     4396    0     2889    95     0    95    95     0     8    0
ffsino     256     4396    0     2889    95     0    95    95     0     8    0
nchpl      144     6613    0     4910    64     0    64    64     0     8    0
rtmask      32       12    0       12     2     1     1     1     0     8    1
vnodes     216     3188    0        0   178     0   178   178     0     8    0
namei      1024   23988    0    23988     3     2     1     2     0     8    1
vcpupl     3904       2    0        1     1     0     1     1     0     8    0
vmpool     808        2    0        1     1     0     1     1     0     8    0
pfiaddrpl  120        1    0        0     1     0     1     1     0     8    0
kstatmem   264      104    0       82     2     0     2     2     0     8    0
scsiplug    72       11    0       11     1     1     0     1     0     8    0
scxspl     216    25987    0    25987     9     7     2     8     1     8    2
plimitpl   152      363    0      346     1     0     1     1     0     8    0
sigapl     424     1888    0     1846     6     0     6     6     0     8    0
knotepl    120   336533    0   336486    46    34    12    17     0     8    8
kqueuepl   184      740    0      731     4     3     1     4     0     8    0
pipepl     304      365    0      338     8     5     3     8     0     8    0
fdescpl    448     1873    0     1845     5     1     4     5     0     8    0
filepl     120    13750    0    13536    16     6    10    16     0     8    0
lockfpl    104      967    0      962     2     1     1     2     0     8    0
lockfspl    48      203    0      199     1     0     1     1     0     8    0
sessionpl  144       38    0       30     1     0     1     1     0     8    0
pgrppl      48       62    0       46     1     0     1     1     0     8    0
ucredpl    104     2176    0     2163     1     0     1     1     0     8    0
zombiepl   144     1892    0     1889     2     1     1     1     0     8    0
processpl  1152    1888    0     1846     4     0     4     4     0     8    0
procpl     664     4047    0     4000     6     0     6     6     0     8    0
sosppl     176       12    0       10     1     0     1     1     0     8    0
sockpl     552     3590    0     3555    21    17     4    20     0     8    0
mcl64k     65536    135    0      135     1     0     1     1     0     8    1
mcl9k      9216       2    0        2     1     1     0     1     0     8    0
mcl8k      8192      18    0       18     2     2     0     1     0     8    0
mcl4k      4096    4363    0     4306    18     9     9    17     0     8    1
mcl2k      2048    2570    0     2563     5     3     2     5     0     8    0
mtagpl      96      172    0       85     4     0     4     4     0     8    0
mbufpl     256    21336    0    21112    97    79    18    78     0     8    0
bufpl      280     8909    0     2688   445     0   445   445     0     8    0
anonpl      24   263487    0   255315   108    33    75    75     0   187    0
amapchunkpl 152   53762    0    53255    56    21    35    40     0   158   12
amappl16   200     4524    0     4265    68    42    26    26     0     8    0
amappl15   192       53    0       52     1     0     1     1     0     8    0
amappl14   184        5    0        5     1     1     0     1     0     8    0
amappl13   176      455    0      453     1     0     1     1     0     8    0
amappl12   168     2266    0     2229     2     0     2     2     0     8    0
amappl11   160        3    0        3     1     1     0     1     0     8    0
amappl10   152       40    0       29     1     0     1     1     0     8    0
amappl9    144      261    0      261     1     1     0     1     0     8    0
amappl8    136       16    0       14     1     0     1     1     0     8    0
amappl7    128       88    0       86     1     0     1     1     0     8    0
amappl6    120      311    0      298     1     0     1     1     0     8    0
amappl5    112       79    0       71     1     0     1     1     0     8    0
amappl4    104      450    0      426     1     0     1     1     0     8    0
amappl3     96    10732    0    10639     4     0     4     4     0     8    0
amappl2     88      646    0      590     2     0     2     2     0     8    0
amappl1     80    18480    0    17949    15     2    13    15     0     8    0
amappl      88    14768    0    14618     6     1     5     5     0    92    0
uvmvnodes   80      141    0        0     3     0     3     3     0     8    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma2048    2048       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      260    0      260     1     1     0     1     0     8    0
dma64       64        7    0        7     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       75    0        5     2     0     2     2     0     8    0
uaddrrnd    24     1873    0     1845     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1873    0     1845     1     0     1     1     0     8    0
vmmpekpl   168    16444    0    16406     3     0     3     3     0     8    0
vmmpekpl: pool(0xffffffff839800b8:vmmpekpl): page inconsistency: page 0x0; at page head addr 0xfffffd80681ecf90 (p 0xfffffd80681ec000)
vmmpepl    168   125046    0   123101   117    16   101   101     0   357    1
vmsppl     368     1872    0     1845     4     1     3     4     0     8    0
rwobjpl     40    33563    0    32286    17     1    16    16     0     8    0
pdppl      4096    3756    0     3693   124    55    69    82     0     8    6
pvpl        32   803698    0   790130   204    55   149   149     0   265    6
pmappl     216     1874    0     1846     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      499    0      168    12     0    12    12     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
uvm_unmap_remove(ffffffff8391e288,ffff800033cfe000,ffff800033d04000,ffff80002a763b98,0,1,486591a487765a35) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff800033cfe000,6000,ffffffff83491068,ffffffff835724f8) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80002a776f98) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ccf8) 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(ffffffff8391e288,ffff800033cfe000,ffff800033d04000,ffff80002a763b98,0,1,486591a487765a35) at uvm_unmap_remove+0x426 sys/uvm/uvm_map.c:1969
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 vm_map_unlock_ln sys/uvm/uvm_map.c:-1 [inline]
uvm_unmap(ffffffff8391e288,ffff800033cfe000,ffff800033d04000) at uvm_unmap+0xa7 sys/uvm/uvm_map.c:1793
km_free(ffff800033cfe000,6000,ffffffff83491068,ffffffff835724f8) at km_free+0x87 sys/uvm/uvm_km.c:714
uvm_uarea_free(ffff80002a776f98) at uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304
reaper(ffff80002a72ccf8) at reaper+0x1a9 sys/kern/kern_exit.c:493
end trace frame: 0x0, count: -5

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.