syzbot


assert "_kernel_lock_held()" failed in uvm_map.c

Status: fixed on 2021/09/03 23:54
Reported-by: syzbot+dd7a70eaf794705db27e@syzkaller.appspotmail.com
Fix commit: 8e114673a836 vmm(4): grab kernel lock before vmspace init
First crash: 460d, last: 459d

Sample crash report:
panic: kernel diagnostic assertion "_kernel_lock_held()" failed: file "/syzkaller/managers/multicore/kernel/sys/uvm/uvm_map.c", line 3641
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*195311  82370      0         0x2          0    0  syz-executor2696
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440
panic(ffffffff824502ee) at panic+0x177 sys/kern/subr_prf.c:202
__assert(ffffffff824bffea,ffffffff824cd928,e39,ffffffff824ce6c6) at __assert+0x25 sys/kern/subr_prf.c:161
uvmspace_free(fffffd806edcaa18) at uvmspace_free+0xe4 sys/uvm/uvm_map.c:3641
vm_impl_init_vmx(ffff800021215c70,ffff8000ffff6550) at vm_impl_init_vmx+0x159
vm_create(ffff800000b29800,ffff8000ffff6550) at vm_create+0x19b vm_impl_init sys/arch/amd64/amd64/vmm.c:1690 [inline]
vm_create(ffff800000b29800,ffff8000ffff6550) at vm_create+0x19b sys/arch/amd64/amd64/vmm.c:1510
vmmioctl(a00,c5005601,ffff800000b29800,1,ffff8000ffff6550) at vmmioctl+0x1f2
VOP_IOCTL(fffffd806ecfc050,c5005601,ffff800000b29800,1,fffffd807f7d8660,ffff8000ffff6550) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:295
vn_ioctl(fffffd806e4a98f8,c5005601,ffff800000b29800,ffff8000ffff6550) at vn_ioctl+0xba sys/kern/vfs_vnops.c:531
sys_ioctl(ffff8000ffff6550,ffff800021228f18,ffff800021228f60) at sys_ioctl+0x4a2
syscall(ffff800021228fe0) at syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800021228fe0) at syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffe1d50, count: 3
https://www.openbsd.org/ddb.html describes the minimum info required in bug
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ddb{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: kernel diagnostic assertion "_kernel_lock_held()" failed: file "/syzkaller/managers/multicore/kernel/sys/uvm/uvm_map.c", line 3641
ddb{0}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440
panic(ffffffff824502ee) at panic+0x177 sys/kern/subr_prf.c:202
__assert(ffffffff824bffea,ffffffff824cd928,e39,ffffffff824ce6c6) at __assert+0x25 sys/kern/subr_prf.c:161
uvmspace_free(fffffd806edcaa18) at uvmspace_free+0xe4 sys/uvm/uvm_map.c:3641
vm_impl_init_vmx(ffff800021215c70,ffff8000ffff6550) at vm_impl_init_vmx+0x159
vm_create(ffff800000b29800,ffff8000ffff6550) at vm_create+0x19b vm_impl_init sys/arch/amd64/amd64/vmm.c:1690 [inline]
vm_create(ffff800000b29800,ffff8000ffff6550) at vm_create+0x19b sys/arch/amd64/amd64/vmm.c:1510
vmmioctl(a00,c5005601,ffff800000b29800,1,ffff8000ffff6550) at vmmioctl+0x1f2
VOP_IOCTL(fffffd806ecfc050,c5005601,ffff800000b29800,1,fffffd807f7d8660,ffff8000ffff6550) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:295
vn_ioctl(fffffd806e4a98f8,c5005601,ffff800000b29800,ffff8000ffff6550) at vn_ioctl+0xba sys/kern/vfs_vnops.c:531
sys_ioctl(ffff8000ffff6550,ffff800021228f18,ffff800021228f60) at sys_ioctl+0x4a2
syscall(ffff800021228fe0) at syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800021228fe0) at syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffe1d50, count: -12
ddb{0}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff800021228a10
rbx               0xffffffff8280abff    cpu_info_full_primary+0x2bff
rdx                             0x8b
rcx                              0x2
rax                             0x8a
r8                0xffffffff81a0be34    kprintf+0x144
r9                               0x1
r10               0x35f160be9f34b416
r11               0x57f8c120b887bbed
r12               0xffffffff8280aa00    cpu_info_full_primary+0x2a00
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff81e3e908    db_enter+0x18
cs                               0x8
rflags                         0x246
rsp               0xffff800021228a00
ss                              0x10
db_enter+0x18:  addq    $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor2696) pid=195311 stat=onproc
    flags process=2<EXEC> proc=0
    pri=52, usrpri=53, nice=20
    forw=0xffffffffffffffff, list=0xffff8000ffff62b0,0xffffffff82913618
    process=0xffff80002120b250 user=0xffff800021224000, vmspace=0xfffffd806edcacf8
    estcpu=3, cpticks=2, pctcpu=0.0
    user=0, sys=2, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
*82370  195311  72488      0  7         0x2                syz-executor2696
 72488  377100    601      0  3    0x10008a  sigsusp       ksh
   601  313503  27811      0  3        0x9a  select        sshd
 66319  126917      1      0  3    0x100083  ttyin         getty
 27811  316788      1      0  3        0x88  select        sshd
 32487  450221  97075     74  3    0x100092  bpf           pflogd
 97075  221379      1      0  3        0x80  netio         pflogd
 16794  378388  16187     73  3    0x100090  kqread        syslogd
 16187  384041      1      0  3    0x100082  netio         syslogd
 51644  140503      1      0  3    0x100080  kqread        resolvd
  5139  396449  25743     77  3    0x100092  kqread        dhcpleased
 90004  466574  25743     77  3    0x100092  kqread        dhcpleased
 25743  289663      1      0  3        0x80  kqread        dhcpleased
 21777   58429      0      0  3     0x14200  bored         smr
 64792  145971      0      0  3     0x14200  pgzero        zerothread
 11634   38687      0      0  3     0x14200  aiodoned      aiodoned
 25498  333544      0      0  3     0x14200  syncer        update
 55072    7069      0      0  3     0x14200  cleaner       cleaner
 59804  432368      0      0  3     0x14200  reaper        reaper
 89820  430452      0      0  3     0x14200  pgdaemon      pagedaemon
 23552  398103      0      0  3     0x14200  bored         crynlk
 94042   22466      0      0  3     0x14200  bored         crypto
 24644  170228      0      0  3     0x14200  bored         viomb
 32135   95644      0      0  3  0x40014200  acpi0         acpi0
 16121  360757      0      0  7  0x40014200                idle1
 79978  101924      0      0  3     0x14200  bored         softnet
 14933   99704      0      0  3     0x14200  bored         systqmp
  5959  244560      0      0  3     0x14200  bored         systq
 70466  185417      0      0  3  0x40014200  bored         softclock
 96045  478917      0      0  3  0x40014200                idle0
     1   39561      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{0}> show all locks
Process 82370 (syz-executor2696) thread 0xffff8000ffff6550 (195311)
exclusive rwlock vmlistlock r = 0 (0xffff800000655c78)
#0  witness_lock+0x4b0 stacktrace_save sys/sys/stacktrace.h:36 [inline]
#0  witness_lock+0x4b0 sys/kern/subr_witness.c:1182
#1  vm_create+0x12e vm_impl_init sys/arch/amd64/amd64/vmm.c:1688 [inline]
#1  vm_create+0x12e sys/arch/amd64/amd64/vmm.c:1510
#2  vmmioctl+0x1f2
#3  VOP_IOCTL+0x9a sys/kern/vfs_vops.c:295
#4  vn_ioctl+0xba sys/kern/vfs_vnops.c:531
#5  sys_ioctl+0x4a2
#6  syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline]
#6  syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587
#7  Xsyscall+0x128
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 10111   6416K    6417K  78643K     11201        0
            pcb    13      8K       8K  78643K        13        0
         rtable    62      2K       2K  78643K       112        0
         ifaddr    29      8K       8K  78643K        30        0
       counters    40     33K      33K  78643K        40        0
       ioctlops     1      2K       4K  78643K      1480        0
          mount     1      1K       1K  78643K         1        0
            log     0      0K       0K  78643K         6        0
         vnodes  1183     74K      75K  78643K      1188        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     2      0K       0K  78643K         2        0
        dirhash    12      2K       2K  78643K        12        0
           ACPI  1697    195K     286K  78643K     12598        0
      file desc     1      0K       0K  78643K         1        0
           proc    67     87K      87K  78643K       278        0
    NFS srvsock     1      0K       0K  78643K         1        0
     NFS daemon     1     16K      16K  78643K         1        0
       in_multi    11      0K       0K  78643K        11        0
    ether_multi     1      0K       0K  78643K         1        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       2K  78643K       348        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    82      3K       6K  78643K      1728        0
       UVM aobj     3      2K       2K  78643K         3        0
        memdesc     1      4K       4K  78643K         1        0
    crypto data     1      1K       1K  78643K         1        0
            NDP     4      0K       0K  78643K         4        0
           temp    23   4193K    4257K  78643K      1962        0
         kqueue     9     12K      12K  78643K         9        0
      SYN cache     2     16K      16K  78643K         2        0
ddb{0}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache    128       22    0        0     1     0     1     1     0     8    0
rtpcb      120       17    0       14     1     0     1     1     0     8    0
rtentry    112       23    0        1     1     0     1     1     0     8    0
unpcb      120       35    0       20     1     0     1     1     0     8    0
syncache   296        5    0        5     1     0     1     1     0     8    1
tcpcb      736        8    0        5     1     0     1     1     0     8    0
arp        120        2    0        0     1     0     1     1     0     8    0
inpcb      304       32    0       26     1     0     1     1     0     8    0
pfosfp      40     1428    0     1005     5     0     5     5     0     8    0
pfosfpen   112     1428    0      714    21     0    21    21     0     8    0
pfstitem    24        8    0        0     1     0     1     1     0     8    0
pfstkey    112        8    0        0     1     0     1     1     0     8    0
pfstate    320        8    0        0     1     0     1     1     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       96    0        0     6     0     6     6     0     8    0
art_table   32       97    0        0     1     0     1     1     0     8    0
art_node    16       22    0        2     1     0     1     1     0     8    0
dirhash    1024      17    0        0     3     0     3     3     0     8    0
dino2pl    256     1413    0       23    87     0    87    87     0     8    0
ffsino     272     1413    0       23    93     0    93    93     0     8    0
nchpl      144     1588    0       40    58     0    58    58     0     8    0
uvmvnodes   72     1423    0        0    26     0    26    26     0     8    0
vnodes     224     1423    0        0    84     0    84    84     0     8    0
namei      1024    4147    0     4147     1     0     1     1     0     8    1
percpumem   16       32    0        0     1     0     1     1     0     8    0
vmpool     560        1    0        0     1     0     1     1     0     8    0
scxspl     216     3479    0     3479     2     1     1     2     0     8    1
plimitpl   152       16    0        9     1     0     1     1     0     8    0
sigapl     424      255    0      224     4     0     4     4     0     8    0
knotepl    112       24    0        0     1     0     1     1     0     8    0
kqueuepl   216        5    0        0     1     0     1     1     0     8    0
pipepl     336       69    0       66     1     0     1     1     0     8    0
fdescpl    496      239    0      224     3     0     3     3     0     8    0
filepl     152     1085    0     1026     3     0     3     3     0     8    0
lockfpl    104        6    0        4     1     0     1     1     0     8    0
lockfspl    48        4    0        2     1     0     1     1     0     8    0
sessionpl  144       18    0        9     1     0     1     1     0     8    0
pgrppl      48       18    0        9     1     0     1     1     0     8    0
ucredpl     96       69    0       57     1     0     1     1     0     8    0
zombiepl   144      224    0      224     1     0     1     1     0     8    1
processpl  1072     255    0      224     3     0     3     3     0     8    0
procpl     672      255    0      224     3     0     3     3     0     8    0
sockpl     480       84    0       60     4     0     4     4     0     8    0
mcl8k      8192       4    0        0     1     0     1     1     0     8    0
mcl4k      4096       2    0        0     1     0     1     1     0     8    0
mcl2k      2048      56    0        0     7     0     7     7     0     8    0
mtagpl      96        2    0        0     1     0     1     1     0     8    0
mbufpl     256      104    0        0     7     0     7     7     0     8    0
bufpl      280     2010    0       90   138     0   138   138     0     8    0
anonpl      24    32861    0    30555    17     2    15    17     0   186    1
amapchunkpl 152    3049    0     2905     8     2     6     8     0   158    0
amappl16   200       95    0       91     1     0     1     1     0     8    0
amappl13   176       18    0       17     1     0     1     1     0     8    0
amappl12   168       17    0       17     1     0     1     1     0     8    1
amappl11   160       55    0       41     1     0     1     1     0     8    0
amappl10   152       26    0       22     1     0     1     1     0     8    0
amappl9    144      221    0      219     1     0     1     1     0     8    0
amappl8    136      275    0      275     1     0     1     1     0     8    1
amappl7    128       52    0       45     1     0     1     1     0     8    0
amappl6    120       86    0       81     1     0     1     1     0     8    0
amappl5    112      173    0      156     1     0     1     1     0     8    0
amappl4    104      529    0      506     1     0     1     1     0     8    0
amappl3     96       48    0       44     1     0     1     1     0     8    0
amappl2     88      400    0      354     2     0     2     2     0     8    0
amappl1     80     7569    0     7191     9     0     9     9     0     8    0
amappl      88     1485    0     1418     2     0     2     2     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      64        2    0        0     1     0     1     1     0     8    0
uaddrrnd    24      240    0      224     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      240    0      224     1     0     1     1     0     8    0
vmmpekpl   168     6035    0     6019     1     0     1     1     0     8    0
vmmpepl    168    22457    0    21609    41     0    41    41     0   357    1
vmsppl     368      239    0      224     2     0     2     2     0     8    0
rwobjpl     56     7021    0     6464     9     0     9     9     0     8    1
pdppl      4096     488    0      448    52    12    40    44     0     8    0
pvpl        32   112189    0   107982    38     0    38    38     0   265    1
pmappl     224      239    0      224     2     0     2     2     0     8    0
extentpl    40       58    0       40     1     0     1     1     0     8    0
phpool     112      268    0       15     8     0     8     8     0     8    0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440
panic(ffffffff824502ee) at panic+0x177 sys/kern/subr_prf.c:202
__assert(ffffffff824bffea,ffffffff824cd928,e39,ffffffff824ce6c6) at __assert+0x25 sys/kern/subr_prf.c:161
uvmspace_free(fffffd806edcaa18) at uvmspace_free+0xe4 sys/uvm/uvm_map.c:3641
vm_impl_init_vmx(ffff800021215c70,ffff8000ffff6550) at vm_impl_init_vmx+0x159
vm_create(ffff800000b29800,ffff8000ffff6550) at vm_create+0x19b vm_impl_init sys/arch/amd64/amd64/vmm.c:1690 [inline]
vm_create(ffff800000b29800,ffff8000ffff6550) at vm_create+0x19b sys/arch/amd64/amd64/vmm.c:1510
vmmioctl(a00,c5005601,ffff800000b29800,1,ffff8000ffff6550) at vmmioctl+0x1f2
VOP_IOCTL(fffffd806ecfc050,c5005601,ffff800000b29800,1,fffffd807f7d8660,ffff8000ffff6550) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:295
vn_ioctl(fffffd806e4a98f8,c5005601,ffff800000b29800,ffff8000ffff6550) at vn_ioctl+0xba sys/kern/vfs_vnops.c:531
sys_ioctl(ffff8000ffff6550,ffff800021228f18,ffff800021228f60) at sys_ioctl+0x4a2
syscall(ffff800021228fe0) at syscall+0x5a9 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800021228fe0) at syscall+0x5a9 sys/arch/amd64/amd64/trap.c:587
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffe1d50, count: -12
ddb{0}> machine ddbcpu 1
Stopped at      x86_ipi_db+0x1a:        addq    $0x8,%rsp
x86_ipi_db(ffff800020d38ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23
acpicpu_idle() at acpicpu_idle+0x2eb sys/dev/acpi/acpicpu.c:1206
sched_idle(ffff800020d38ff0) at sched_idle+0x417 sys/kern/kern_sched.c:178
end trace frame: 0x0, count: 10
ddb{1}> trace
x86_ipi_db(ffff800020d38ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23
acpicpu_idle() at acpicpu_idle+0x2eb sys/dev/acpi/acpicpu.c:1206
sched_idle(ffff800020d38ff0) at sched_idle+0x417 sys/kern/kern_sched.c:178
end trace frame: 0x0, count: -5
ddb{1}> 

Crashes (11):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-openbsd-multicore 2021/09/01 06:03 openbsd 444296aeff58 7eb7e152 .config log report syz C assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 05:41 openbsd 444296aeff58 7eb7e152 .config log report syz C assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/02 06:02 openbsd e42df31d2641 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:54 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:50 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:49 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:45 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:43 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:43 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:39 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
ci-openbsd-multicore 2021/09/01 03:38 openbsd 444296aeff58 7eb7e152 .config log report assert "_kernel_lock_held()" failed in uvm_map.c
* Struck through repros no longer work on HEAD.