syzbot


uvm_fault: ffs2_balloc (3)

Status: upstream: reported on 2024/01/20 01:54
Reported-by: syzbot+4ce157a9575505d57968@syzkaller.appspotmail.com
First crash: 147d, last: 44d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd uvm_fault: ffs2_balloc (2) 3 453d 522d 0/3 auto-obsoleted due to no activity on 2023/06/18 20:00
openbsd uvm_fault: ffs2_balloc 1 821d 821d 0/3 auto-closed as invalid on 2022/06/14 20:58

Sample crash report:
uvm_fault(0xffffffff82e52678, 0xffff8000272b2088, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ffs2_balloc+0x78e:      movq    0(%rcx,%rax,8),%r14
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*416570  20287     73  0x19100010          0    0  syslogd
ffs2_balloc(fffffd806ee12e20,770fa,68,fffffd807f7d78f0,1,ffff80002a6593d8) at ffs2_balloc+0x78e sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a659460) at ffs_write+0x3c7 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd807aac2a68,ffff80002a659680,3,fffffd807f7d78f0) at VOP_WRITE+0xc3 sys/kern/vfs_vops.c:245
vn_write(fffffd806f2141e8,ffff80002a659680,0) at vn_write+0x157 sys/kern/vfs_vnops.c:408
dofilewritev(ffff80002a62d9b0,e,ffff80002a659680,0,ffff80002a659740) at dofilewritev+0x1a9 sys/kern/sys_generic.c:375
sys_writev(ffff80002a62d9b0,ffff80002a6597f0,ffff80002a659740) at sys_writev+0xab sys/kern/sys_generic.c:322
syscall(ffff80002a6597f0) at syscall+0x72a sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f77de937700, count: 7
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(0xffffffff82e52678, 0xffff8000272b2088, 0, 1) -> d
ddb> trace
ffs2_balloc(fffffd806ee12e20,770fa,68,fffffd807f7d78f0,1,ffff80002a6593d8) at ffs2_balloc+0x78e sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a659460) at ffs_write+0x3c7 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd807aac2a68,ffff80002a659680,3,fffffd807f7d78f0) at VOP_WRITE+0xc3 sys/kern/vfs_vops.c:245
vn_write(fffffd806f2141e8,ffff80002a659680,0) at vn_write+0x157 sys/kern/vfs_vnops.c:408
dofilewritev(ffff80002a62d9b0,e,ffff80002a659680,0,ffff80002a659740) at dofilewritev+0x1a9 sys/kern/sys_generic.c:375
sys_writev(ffff80002a62d9b0,ffff80002a6597f0,ffff80002a659740) at sys_writev+0xab sys/kern/sys_generic.c:322
syscall(ffff80002a6597f0) at syscall+0x72a sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f77de937700, count: -8
ddb> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a659380
rbx               0xfffffd806ee12e20
rdx                                0
rcx               0xffff8000272b2000
rax                             0x11
r8                0xffffffffffffffff
r9                0xffff80002a6593d8
r10               0x95cc26294139dde3
r11               0xdd0298ba5c1aedc0
r12                             0x10
r13                              0x1
r14                       0xffffffff
r15               0xfffffd80770cf7b8
rip               0xffffffff81ac3b8e    ffs2_balloc+0x78e
cs                               0x8
rflags                       0x10202    __ALIGN_SIZE+0xf202
rsp               0xffff80002a659210
ss                              0x10
ffs2_balloc+0x78e:      movq    0(%rcx,%rax,8),%r14
ddb> show proc
PROC (syslogd) tid=416570 pid=20287 tcnt=1 stat=onproc
    flags process=19100010<SUGID,PLEDGE,CHROOT> proc=0
    runpri=17, usrpri=50, slppri=17, nice=20
    wchan=0x0, wmesg=, ps_single=0x0
    forw=0xffffffffffffffff, list=0xffff80002a62d720,0xffff80002a62ca60
    process=0xffff8000ffff7ab0 user=0xffff80002a654000, vmspace=0xfffffd807aabc008
    estcpu=0, cpticks=1, pctcpu=0.2, user=0, sys=1, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 42456  141399  56597      0  2   0x8000000                syz-executor.4
 42456  217859  56597      0  3   0xc000080  fsleep        syz-executor.4
 51456  116115  72231      0  2   0x8000000                syz-executor.6
 51456  215161  72231      0  3   0xc000080  fsleep        syz-executor.6
 49789  246195  78312      0  2   0x8000000                syz-executor.2
 49789  280077  78312      0  3   0xc000080  fsleep        syz-executor.2
 44968  184806  24304      0  2   0x8000000                syz-executor.0
 44968  178357  24304      0  2   0xc000000                syz-executor.0
 97031  488345  35548      0  2   0x8100002                sh
 24506  136178  81521      0  2   0x8100002                sh
 35548  523801  64216      0  3   0x8000082  wait          syz-executor.3
 69305  189840  79896      0  2   0x8100000                sh
 79896  131475  66325      0  3   0x810008a  sigsusp       sh
 72231  151926  64216      0  2   0x8000482                syz-executor.6
 54884  175989  64216      0  2   0x8000482                syz-executor.1
 56597   15597  64216      0  2   0x8000482                syz-executor.4
 78312  279134  64216      0  2   0x8000482                syz-executor.2
 81521   19098  64216      0  3   0x8000082  wait          syz-executor.7
 24304  377460  64216      0  2   0x8000482                syz-executor.0
 66325  166572  64216      0  3   0x8000082  wait          syz-executor.5
 72197  508720      0      0  3     0x14200  bored         sosplice
 64216   55716  16336      0  3  0x1a000082  thrsleep      syz-fuzzer
 64216  441119  16336      0  2  0x1e000482                syz-fuzzer
 64216  323269  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216  130127  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216   38180  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216  342300  16336      0  3  0x1e000082  kqread        syz-fuzzer
 64216  205775  16336      0  3  0x1e000082  thrsleep      syz-fuzzer
 64216  437076  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216   60680  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216  293871  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216  363865  16336      0  3  0x1e000082  thrsleep      syz-fuzzer
 64216  183034  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216  119797  16336      0  3  0x1e000082  wait          syz-fuzzer
 64216  283574  16336      0  3  0x1e000082  thrsleep      syz-fuzzer
 16336  306922  70340      0  3   0x810008a  sigsusp       ksh
 70340  427129  28278      0  3  0x1800009a  kqread        sshd
 95585   25934      1      0  3  0x18100083  ttyin         getty
 28278   52477      1      0  3  0x18000088  kqread        sshd
*20287  416570  10265     73  7  0x19100010                syslogd
 10265  261748      1      0  3  0x18100082  sbwait        syslogd
 45390    5754      1      0  3  0x18100080  kqread        resolvd
 83395  385252   5729     77  3  0x18100092  kqread        dhcpleased
 19611  492319   5729     77  3  0x18100092  kqread        dhcpleased
  5729  181796      1      0  3  0x18000080  kqread        dhcpleased
 27449  171986      0      0  3     0x14200  bored         smr
 18317  468871      0      0  2     0x14200                zerothread
 74491  436494      0      0  3     0x14200  aiodoned      aiodoned
 55169  309160      0      0  2     0x14600                update
 90509  382902      0      0  3     0x14200  cleaner       cleaner
 96242   59431      0      0  3     0x14200  reaper        reaper
 91484  434465      0      0  3     0x14200  pgdaemon      pagedaemon
 99574  329539      0      0  3     0x14200  bored         viomb
 52052  332505      0      0  3  0x40014200  acpi0         acpi0
 76430  313276      0      0  3     0x14200  bored         softnet3
 59366   85745      0      0  3     0x14200  bored         softnet2
  8822   91535      0      0  3     0x14200  bored         softnet1
 68985   67042      0      0  3     0x14200  bored         softnet0
 79782  457193      0      0  3     0x14200  bored         systqmp
 86521   83594      0      0  3     0x14200  bored         systq
 21569  101246      0      0  3  0x40014200  tmoslp        softclock
 68259  300202      0      0  3  0x40014200                idle0
     1   82737      0      0  3   0x8000082  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 10179   6542K    6864K 166960K     12129        0
            pcb    17     12K      12K 166960K        87        0
         rtable   213      6K       7K 166960K      1164        0
             pf    29      8K       9K 166960K        98        0
         ifaddr    40     11K      12K 166960K       157        0
        ifgroup    50      2K       2K 166960K       181        0
         sysctl     3      1K       1K 166960K         5        0
       counters    30     17K      17K 166960K        61        0
       ioctlops     0      0K       2K 166960K        73        0
            iov     0      0K      28K 166960K        31        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1382     87K      87K 166960K      2052        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       9K 166960K        12        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       1K 166960K        44        0
        dirhash    12      2K       2K 166960K        24        0
           ACPI  1697    195K     286K 166960K     12548        0
      file desc    18     65K     101K 166960K      1008        0
          sigio     0      0K       0K 166960K        11        0
           proc    58     59K     132K 166960K      1227        0
        subproc   104      6K       7K 166960K       442        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K        59        0
       in_multi    88      6K       7K 166960K       381        0
    ether_multi     1      0K       0K 166960K         1        0
            mrt     0      0K       0K 166960K         2        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys    67    307K     307K 166960K        67        0
           exec     0      0K       1K 166960K       795        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   267     79K      85K 166960K      9552        0
       UVM aobj    17      4K       4K 166960K        17        0
     pinsyscall    38     76K     100K 166960K      2808        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        24        0
            NDP    25      1K       2K 166960K       108        0
           temp    74   6812K   14742K 166960K     12632        0
         kqueue    12     18K      24K 166960K        78        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      121    0      118     1     0     1     1     0     8    0
rtentry    112      405    0      307     4     0     4     4     0     8    1
unpcb      144      391    0      377     2     0     2     2     0     8    1
syncache   336        9    0        9     1     0     1     1     0     8    1
sackhl      24        3    0        3     1     0     1     1     0     8    1
tcpqe       32        1    0        1     1     0     1     1     0     8    1
tcpcb      808      211    0      205     2     0     2     2     0     8    1
arp         88       74    0       58     1     0     1     1     0     8    0
ipq         40        3    0        3     1     0     1     1     0     8    1
ipqe        40       48    0       48     1     0     1     1     0     8    1
inpcb      352      813    0      804     8     0     8     8     0     8    6
nd6        104      100    0       80     1     0     1     1     0     8    0
pkpcb       40        7    0        7     1     0     1     1     0     8    1
kcovpl      48       34    0       26     1     0     1     1     0     8    0
ppxss      1072       2    0        2     1     0     1     1     0     8    1
art_heap8  4096       1    0        0     1     0     1     1     0     8    0
art_heap4  256     1599    0     1189    41    15    26    30     0     8    0
art_table   32     1600    0     1189     4     0     4     4     0     8    0
art_node    16      404    0      315     1     0     1     1     0     8    0
sysvmsgpl   40       41    0        1     1     0     1     1     0     8    0
semupl     112        1    0        1     1     0     1     1     0     8    1
semapl     112       41    0       31     1     0     1     1     0     8    0
shmpl      112       14    0        0     1     0     1     1     0     8    0
dirhash    1024      25    0        8     3     0     3     3     0     8    0
dino2pl    256     2495    0      985    96     0    96    96     0     8    0
ffsino     240     2495    0      985    90     0    90    90     0     8    0
nchpl      144     3705    0     1969    66     0    66    66     0     8    0
uvmvnodes   80     3163    0        0    65     0    65    65     0     8    0
vnodes     216     3163    0        0   176     0   176   176     0     8    0
namei      1024   15249    0    15249     2     0     2     2     0     8    2
kstatmem   264       84    0       62     2     0     2     2     0     8    0
scsiplug    72        3    0        3     1     0     1     1     0     8    1
scxspl     216    21329    0    21329     8     0     8     8     1     8    8
plimitpl   152      129    0      112     1     0     1     1     0     8    0
sigapl     424     1251    0     1204     7     0     7     7     0     8    1
futexpl     64     9540    0     9537     1     0     1     1     0     8    0
knotepl    120     5452    0     5364    11     0    11    11     0     8    7
kqueuepl   184      167    0      159     1     0     1     1     0     8    0
pipepl     288      297    0      269     3     0     3     3     0     8    0
fdescpl    432     1234    0     1205     5     0     5     5     0     8    1
filepl     120     6332    0     6089    10     0    10    10     0     8    2
lockfpl    104      191    0      189     1     0     1     1     0     8    0
lockfspl    48       72    0       70     1     0     1     1     0     8    0
sessionpl  144       49    0       33     1     0     1     1     0     8    0
pgrppl      48       55    0       39     1     0     1     1     0     8    0
ucredpl    104      711    0      698     1     0     1     1     0     8    0
zombiepl   144     1205    0     1204     1     0     1     1     0     8    0
processpl  1072    1251    0     1204     4     0     4     4     0     8    0
procpl     656     1919    0     1855     7     0     7     7     0     8    0
sosppl     168       10    0       10     1     0     1     1     0     8    1
sockpl     504     1340    0     1314    13     2    11    13     0     8    7
mcl64k     65536      6    0        6     1     0     1     1     0     8    1
mcl8k      8192      15    0       15     1     0     1     1     0     8    1
mcl4k      4096      10    0       10     1     0     1     1     0     8    1
mcl2k      2048   19495    0    19397    38    17    21    36     0     8    7
mtagpl      96       27    0       27     1     0     1     1     0     8    1
mbufpl     256    40819    0    40570    33     7    26    28     0     8    7
bufpl      280     7282    0      953   453     0   453   453     0     8    0
anonpl      24   306036    0   295573    85     0    85    85     0   188   21
amapchunkpl 152   31836    0    30932    39     0    39    39     0   158    4
amappl16   200     7017    0     6936    26    11    15    19     0     8    8
amappl15   192       17    0       17     1     0     1     1     0     8    1
amappl14   184      275    0      261     2     0     2     2     0     8    1
amappl13   176       14    0       14     1     0     1     1     0     8    1
amappl12   168     2225    0     2195     2     0     2     2     0     8    0
amappl11   160       49    0       38     1     0     1     1     0     8    0
amappl10   152      112    0      101     1     0     1     1     0     8    0
amappl9    144      160    0      160     1     0     1     1     0     8    1
amappl8    136      185    0      156     2     0     2     2     0     8    0
amappl7    128       52    0       38     1     0     1     1     0     8    0
amappl6    120      642    0      624     2     0     2     2     0     8    1
amappl5    112      264    0      252     1     0     1     1     0     8    0
amappl4    104      674    0      645     2     0     2     2     0     8    1
amappl3     96     6399    0     6323     3     0     3     3     0     8    0
amappl2     88     1699    0     1628     3     0     3     3     0     8    1
amappl1     80    13737    0    13237    22     3    19    22     0     8    7
amappl      88     8831    0     8647     5     0     5     5     0    92    0
dma4096    4096       1    0        1     1     0     1     1     0     8    1
dma1024    1024       1    0        0     1     0     1     1     0     8    0
dma256     256        6    0        6     1     0     1     1     0     8    1
dma128     128      253    0      253     1     0     1     1     0     8    1
dma64       64        6    0        6     1     0     1     1     0     8    1
dma32       32        7    0        7     1     0     1     1     0     8    1
dma16       16       18    0       17     1     0     1     1     0     8    0
aobjpl      72       16    0        0     1     0     1     1     0     8    0
uaddrrnd    24     1234    0     1205     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     1234    0     1205     1     0     1     1     0     8    0
vmmpekpl   168    13921    0    13866     3     0     3     3     0     8    0
vmmpepl    168   100998    0    99247   111     0   111   111     0   357   28
vmsppl     344     1233    0     1205     4     0     4     4     0     8    0
rwobjpl     24    34381    0    30164    27     0    27    27     0     8    0
pdppl      4096    2474    0     2410   160    84    76    82     0     8   12
pvpl        32   726474    0   706963   357    20   337   357     0   265  179
pmappl     216     1233    0     1205     3     0     3     3     0     8    1
extentpl    40       56    0       38     1     0     1     1     0     8    0
phpool     112      489    0      125    11     0    11    11     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
ffs2_balloc(fffffd806ee12e20,770fa,68,fffffd807f7d78f0,1,ffff80002a6593d8) at ffs2_balloc+0x78e sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a659460) at ffs_write+0x3c7 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd807aac2a68,ffff80002a659680,3,fffffd807f7d78f0) at VOP_WRITE+0xc3 sys/kern/vfs_vops.c:245
vn_write(fffffd806f2141e8,ffff80002a659680,0) at vn_write+0x157 sys/kern/vfs_vnops.c:408
dofilewritev(ffff80002a62d9b0,e,ffff80002a659680,0,ffff80002a659740) at dofilewritev+0x1a9 sys/kern/sys_generic.c:375
sys_writev(ffff80002a62d9b0,ffff80002a6597f0,ffff80002a659740) at sys_writev+0xab sys/kern/sys_generic.c:322
syscall(ffff80002a6597f0) at syscall+0x72a sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f77de937700, count: -8
ddb> machine ddbcpu 1
No such command
ddb> trace
ffs2_balloc(fffffd806ee12e20,770fa,68,fffffd807f7d78f0,1,ffff80002a6593d8) at ffs2_balloc+0x78e sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a659460) at ffs_write+0x3c7 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd807aac2a68,ffff80002a659680,3,fffffd807f7d78f0) at VOP_WRITE+0xc3 sys/kern/vfs_vops.c:245
vn_write(fffffd806f2141e8,ffff80002a659680,0) at vn_write+0x157 sys/kern/vfs_vnops.c:408
dofilewritev(ffff80002a62d9b0,e,ffff80002a659680,0,ffff80002a659740) at dofilewritev+0x1a9 sys/kern/sys_generic.c:375
sys_writev(ffff80002a62d9b0,ffff80002a6597f0,ffff80002a659740) at sys_writev+0xab sys/kern/sys_generic.c:322
syscall(ffff80002a6597f0) at syscall+0x72a sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f77de937700, count: -8

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/02 16:14 openbsd 3ad4051d1cf6 3ba885bc .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: ffs2_balloc
2024/04/08 00:31 openbsd c112ccd4e935 ca620dd8 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: ffs2_balloc
2024/03/30 23:42 openbsd 2ee472d028ec 6ee49f2e .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: ffs2_balloc
2024/03/02 01:06 openbsd 609b293af4bd 83acf9e0 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: ffs2_balloc
2024/01/20 01:53 openbsd 59674edd175d 9bd8dcda .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: ffs2_balloc
* Struck through repros no longer work on HEAD.