syzbot


panic: pool_p_free: rttmr free list modified: page ADDR; item addr ADDR; offset 0x10=ADDR

Status: upstream: reported on 2025/08/08 06:04
Reported-by: syzbot+8f3c9b0e07d02ecd65ac@syzkaller.appspotmail.com
First crash: 24d, last: 24d

Sample crash report:
panic: pooWlAR_NpI_fNrGe:e :S PL rNOtTt mLr OWEfrReEDe  liOsN tS YmoSdiCfAiLedL:  8pa3 g-2e096 20xf5f803ff2f dEX8IT0 05 eaff
600Stopped at   savectx+0xae:   movl    $0,%gs:0x688
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
 312160  61853      0           0  0x4000000    1  syz-executor
*293351  46508      0           0          0    0  syz-executor
savectx() at savectx+0xae
end of kernel
end trace frame: 0x7638ce0ced40, count: 14
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{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu1: pool_p_free: rttmr free list modified: page 0xfffffd805eff6000; item addr 0xfffffd805eff6ee8; offset 0x10=0x838b61d0
ddb{0}> trace
savectx() at savectx+0xae
end of kernel
end trace frame: 0x7638ce0ced40, count: -1
ddb{0}> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a3ad810
rbx                                0
rdx                                0
rcx               0xffff80003c4554e8
rax                             0x3c
r8                0xffff80002a3ad740
r9                                 0
r10               0xa92d8e19789e53c7
r11                0x58601a94a52865b
r12                                0
r13                                0
r14               0xffff80003c4554e8
r15                                0
rip               0xffffffff819763ee    savectx+0xae
cs                               0x8
rflags                          0x46
rsp               0xffff80002a3ad790
ss                              0x10
savectx+0xae:   movl    $0,%gs:0x688
ddb{0}> show proc
PROC (syz-executor) tid=293351 pid=46508 tcnt=3 stat=onproc
    flags process=0 proc=0
    runpri=84, usrpri=84, slppri=16, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff800037810d38,0xffff80003c454fc8
    process=0xffff80003c026720 user=0xffff80002a3a8000, vmspace=0xfffffd800ef9f9a8
    estcpu=34, cpticks=3, pctcpu=0.2, user=1, sys=2, intr=0
ddb{0}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 71070  156201  58746      0  2           0                syz-executor
 71070   21030  58746      0  3   0x4000080  fsleep        syz-executor
 38165  112944  89147      0  2           0                syz-executor
 38165  204741  89147      0  3   0x4000080  fsleep        syz-executor
 61853  214342  74611      0  2           0                syz-executor
 61853  127633  74611      0  3   0x4000080  fsleep        syz-executor
 61853  312160  74611      0  7   0x4000000                syz-executor
*46508  293351  58118      0  7           0                syz-executor
 46508  310399  58118      0  3   0x4000080  kqsel         syz-executor
 46508  450021  58118      0  3   0x4000080  fsleep        syz-executor
 95640  257815  12222      0  2           0                syz-executor
 95640  334314  12222      0  3   0x4000080  fsleep        syz-executor
 95640   68110  12222      0  3   0x4000080  fsleep        syz-executor
 58746  210919  69834      0  3        0x82  nanoslp       syz-executor
 26760  326336      0      0  3     0x14280  nfsidl        nfsio
 62194   10732      0      0  3     0x14280  nfsidl        nfsio
 55498  283789  69834      0  3        0x82  nanoslp       syz-executor
 74611  139935  69834      0  3        0x82  nanoslp       syz-executor
 71224  343414      1      0  3    0x100083  ttyopn        getty
 58118  312590  69834      0  3        0x82  nanoslp       syz-executor
  3445  217027      0      0  3     0x14200  bored         sosplice
 10530   61396  69834      0  3        0x82  nanoslp       syz-executor
 89147   94183  69834      0  3        0x82  nanoslp       syz-executor
 43245   66385  69834      0  2         0x2                syz-executor
 12222  362445  69834      0  3        0x82  nanoslp       syz-executor
 69834  484330  27338      0  3        0x82  kqread        syz-executor
 27338  241984  98831      0  3    0x10008a  sigsusp       ksh
 98831  417700  40819      0  3        0x98  kqread        sshd-session
 40819  303065    130      0  3        0x92  kqread        sshd-session
   130   18172      1      0  3        0x88  kqread        sshd
 56933  462680  29681     74  3   0x1100092  bpf           pflogd
 29681   11702      1      0  3        0x80  sbwait        pflogd
 38367  149599  60551     73  3   0x1100090  kqread        syslogd
 60551  263404      1      0  3    0x100082  sbwait        syslogd
 94024  266688      1      0  3    0x100080  kqread        resolvd
 36045  415687  67183     77  3    0x100092  kqread        dhcpleased
 91166  319692  67183     77  3    0x100092  kqread        dhcpleased
 67183  246680      1      0  3        0x80  kqread        dhcpleased
 77687   48205      0      0  3     0x14200  bored         smr
   814  278291      0      0  2     0x14200                zerothread
 99506  473557      0      0  3     0x14200  aiodoned      aiodoned
 94899  486591      0      0  3     0x14200  syncer        update
  1821  378886      0      0  3     0x14200  cleaner       cleaner
 53651  197763      0      0  2     0x14200                reaper
  3058  131629      0      0  3     0x14200  pgdaemon      pagedaemon
 86548   55153      0      0  3     0x14200  bored         viomb
  5565  132016      0      0  3  0x40014200  acpi0         acpi0
 24208  502008      0      0  3  0x40014200                idle1
 98098  369663      0      0  3     0x14200  bored         softnet7
 16588  258881      0      0  3     0x14200  bored         softnet6
 61329  511558      0      0  3     0x14200  bored         softnet5
 61668   17585      0      0  3     0x14200  bored         softnet4
 13769  512312      0      0  3     0x14200  bored         softnet3
 94197  370886      0      0  3     0x14200  bored         softnet2
 98631  366941      0      0  3     0x14200  bored         softnet1
   571  209835      0      0  3     0x14200  bored         softnet0
 45563  150304      0      0  3     0x14200  bored         systqmp
 46060  425545      0      0  3     0x14200  bored         systq
  8499  115290      0      0  3     0x14200  tmoslp        softclockmp
 81510  249252      0      0  3  0x40014200  tmoslp        softclock
 59931  301232      0      0  3  0x40014200                idle0
     1  326378      0      0  3        0x82  wait          init
     0       0     -1      0  3  0x10010200  scheduler     swapper
ddb{0}> show all locks
CPU 0:
exclusive mutex &pmap->pm_mtx r = 0 (0xfffffd806b7b7310)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  mtx_enter_try+0x1ad sys/kern/kern_lock.c:311
#2  mtx_enter+0x62 sys/kern/kern_lock.c:261
#3  pmap_do_remove+0xa9 rcr3 sys/arch/amd64/compile/SYZKALLER/obj/machine/cpufunc.h:139 [inline]
#3  pmap_do_remove+0xa9 pmap_map_ptes sys/arch/amd64/amd64/pmap.c:437 [inline]
#3  pmap_do_remove+0xa9 sys/arch/amd64/amd64/pmap.c:1824
#4  uvm_unmap_kill_entry_withlock+0x269 sys/uvm/uvm_map.c:1863
#5  uvm_map_teardown+0x117 uvm_map_addr_RBT_LEFT sys/uvm/uvm_map.h:-1 [inline]
#5  uvm_map_teardown+0x117 sys/uvm/uvm_map.c:2486
#6  exit1+0x6fc sys/kern/kern_exit.c:260
#7  proc_suspend_check_locked+0x2fd sys/kern/kern_sig.c:2235
#8  userret+0x8c proc_suspend_check sys/kern/kern_sig.c:-1 [inline]
#8  userret+0x8c sys/kern/kern_sig.c:2194
#9  intr_user_exit+0x3c
Process 61853 (syz-executor) thread 0xffff800037810aa0 (312160)
Process 43245 (syz-executor) thread 0xffff8000ffff2fa0 (66385)
ddb{0}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 10246  11054K   12654K 166960K     15204        0
            pcb    17     16K      18K 166960K       996        0
         rtable   212     12K      13K 166960K       705        0
             pf    42     19K   67486K 166960K       378        0
         ifaddr    43      9K      10K 166960K       240        0
        ifgroup    63      2K       3K 166960K       459        0
         sysctl     4      1K       9K 166960K        63        0
       counters    70     37K      38K 166960K       432        0
       ioctlops     0      0K       4K 166960K      1974        0
            iov     0      0K      18K 166960K       223        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1491     94K      95K 166960K      4084        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K       9K 166960K        38        0
         VM map     2      1K       1K 166960K         2        0
            sem    12      0K       0K 166960K       183        0
        dirhash    12      2K       2K 166960K        75        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    16     57K     240K 166960K      2966        0
          sigio     0      0K       0K 166960K        88        0
           proc    72    115K     164K 166960K      1112        0
        subproc    72      4K       4K 166960K       136        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K       502        0
       in_multi    84      6K       7K 166960K       338        0
    ether_multi     1      0K       0K 166960K        41        0
            mrt     2      0K       0K 166960K        18        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   253   1129K    1129K 166960K       253        0
           exec     0      0K       1K 166960K      1079        0
   fusefs mount     1     32K      32K 166960K         1        0
     pfkey data     0      0K       0K 166960K         3        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   232    161K     180K 166960K     27959        0
       UVM aobj    57      2K       2K 166960K        61        0
     pinsyscall    41     82K     106K 166960K      4251        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K       145        0
            NDP    13      0K       2K 166960K       165        0
           temp    83   8652K   29644K 166960K    123677        0
         kqueue    13     20K      31K 166960K       591        0
      SYN cache     2     16K      16K 166960K         2        0
ddb{0}> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache    128       26    0        0     1     0     1     1     0     8    0
rtpcb      120      248    0      245     1     0     1     1     0     8    0
rtentry    176      237    0      160     5     0     5     5     0     8    0
unpcb      144     2395    0     2374    23    22     1     6     0     8    0
syncache   336        7    0        7     2     2     0     1     0     8    0
tcpqe       32        3    0        3     2     2     0     1     0     8    0
tcpcb      736     1271    0     1260    26    24     2     8     0     8    0
arp        128       22    0       13     1     0     1     1     0     8    0
inpcb      328     3860    0     3846    33    31     2     8     0     8    0
nd6        144       37    0       21     1     0     1     1     0     8    0
pkpcb       40       85    0       85     6     6     0     1     0     8    0
kcovpl      48       15    0        7     1     0     1     1     0     8    0
ppxss      1192     126    0      126     3     3     0     1     0     8    0
pppxif     1504      26    0       26     6     6     0     1     0     8    0
pfstscr     40        2    0        2     1     1     0     1     0     8    0
pffrag     232       58    0       50     1     0     1     1     0   482    0
pffrnode    88       57    0       49     1     0     1     1     0     8    0
pffrent     40      105    0       97     1     0     1     1     0     8    0
pfosfp      40     1430    0     1005     5     0     5     5     0     8    0
pfosfpen   112     1430    0      714    21     0    21    21     0     8    0
pfanchor   1288       1    0        0     1     0     1     1     0     8    0
pftag       88        1    0        0     1     0     1     1     0     8    0
pfstitem    24      193    0       93     1     0     1     1     0     8    0
pfstkey    128      198    0       99     4     0     4     4     0     8    0
pfstate    384      195    0       96    11     0    11    11     0     8    0
pfrule     1344      35    0       29     2     1     1     2     0     8    0
rttmr      136        6    0        6     2     2     0     1     0     8    0
art_heap8  4096       6    0        1     6     1     5     5     0     8    0
art_heap4  256     1206    0      836    35    10    25    30     0     8    1
art_table   40     1212    0      837     5     0     5     5     0     8    0
art_node    32      233    0      167     1     0     1     1     0     8    0
sysvmsgpl   40       21    0       13     1     0     1     1     0     8    0
semupl     112        1    0        1     1     1     0     1     0     8    0
semapl     112      177    0      167     1     0     1     1     0     8    0
shmpl      112       58    0        4     2     0     2     2     0     8    0
dirhash    1024      60    0       43     3     0     3     3     0     8    0
dino2pl    256     7006    0     5481    96     0    96    96     0     8    0
ffsino     296     7006    0     5481   119     1   118   118     0     8    0
nchpl      144    11053    0     9340    65     0    65    65     0     8    0
rtmask      32       25    0       25     7     6     1     1     0     8    1
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   41275    0    41275     6     5     1     2     0     8    1
percpumem   16      231    0      181     1     0     1     1     0     8    0
kstatmem   264      274    0      244     4     1     3     3     0     8    0
acpiwqpl    32        2    0        2     1     0     1     1     1     8    1
scsiplug    72       18    0       18     5     4     1     1     0     8    1
scxspl     216    79284    0    79284    15    13     2     8     1     8    2
plimitpl   152      917    0      900     1     0     1     1     0     8    0
sigapl     424     3274    0     3218     9     1     8     9     0     8    0
knotepl    120      790    0        0    24     0    24    24     0     8    0
kqueuepl   224     1333    0     1323    18    17     1     5     0     8    0
pipepl     344      685    0      658    19    10     9     9     0     8    6
fdescpl    528     3215    0     3185     3     0     3     3     0     8    0
filepl     160    24401    0    24178    31    13    18    19     0     8    6
lockfpl    104     1504    0     1502     4     2     2     2     0     8    1
lockfspl    48      502    0      500     1     0     1     1     0     8    0
sessionpl  144       33    0       24     1     0     1     1     0     8    0
pgrppl      48      175    0      158     1     0     1     1     0     8    0
ucredpl    104     3939    0     3926     1     0     1     1     0     8    0
zombiepl   144     3466    0     3464     2     1     1     1     0     8    0
processpl  1248    3274    0     3218     6     1     5     6     0     8    0
procpl     664     8073    0     8009     9     2     7     9     0     8    0
sosppl     168       31    0       31     6     5     1     1     0     8    1
sockpl     752     6739    0     6701    73    61    12    24     0     8    7
mcl64k     65536     15    0        0     2     0     2     2     0     8    0
mcl16k     16384      7    0        0     1     0     1     1     0     8    0
mcl12k     12288      2    0        0     1     0     1     1     0     8    0
mcl9k      9216       2    0        0     1     0     1     1     0     8    0
mcl8k      8192       3    0        0     1     0     1     1     0     8    0
mcl4k      4096     123    0        0    15     0    15    15     0     8    0
mcl2k2     2112       1    0        0     1     0     1     1     0     8    0
mcl2k      2048      99    0        0     9     0     9     9     0     8    0
mtagpl      96       98    0        0     3     0     3     3     0     8    0
mbufpl     256      301    0        0    16     0    16    16     0     8    0
bufpl      280    31864    0    25721   440     1   439   440     0     8    0
anonpl      32    14929    0        0   120     0   120   120     0   246    0
amapchunkpl 152   97354    0    96896    52    22    30    33     0   158    6
amappl16   200    11203    0    11164    94    78    16    35     0     8    5
amappl15   192        5    0        5     1     1     0     1     0     8    0
amappl14   184      181    0      168     1     0     1     1     0     8    0
amappl13   176       19    0       19     1     1     0     1     0     8    0
amappl12   168     3993    0     3962     3     1     2     2     0     8    0
amappl11   160       79    0       65     1     0     1     1     0     8    0
amappl10   152       18    0       18     3     3     0     1     0     8    0
amappl9    144      255    0      254     2     1     1     1     0     8    0
amappl8    136       19    0       16     1     0     1     1     0     8    0
amappl7    128      136    0      122     1     0     1     1     0     8    0
amappl6    120      256    0      252     1     0     1     1     0     8    0
amappl5    112      152    0      142     1     0     1     1     0     8    0
amappl4    104      318    0      297     1     0     1     1     0     8    0
amappl3     96    20294    0    20188     5     1     4     4     0     8    0
amappl2     88      859    0      795     2     0     2     2     0     8    0
amappl1     80    20907    0    20309    16     2    14    16     0     8    0
amappl      88    26625    0    26468     5     0     5     5     0    92    0
dma16384   16384      1    0        1     1     0     1     1     0     8    1
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma1024    1024       1    0        0     1     0     1     1     0     8    0
dma512     512        1    0        1     1     1     0     1     0     8    0
dma256     256        7    0        7     2     2     0     1     0     8    0
dma128     128      261    0      261     3     2     1     1     0     8    1
dma64       64        8    0        8     3     3     0     1     0     8    0
dma32       32        7    0        7     1     1     0     1     0     8    0
dma16       16       23    0       22     1     0     1     1     0     8    0
aobjpl      72       60    0        4     2     0     2     2     0     8    0
uaddrrnd    24     3215    0     3185     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24     3215    0     3185     1     0     1     1     0     8    0
vmmpekpl   168    25722    0    25664     4     0     4     4     0     8    0
vmmpepl    168   205659    0   203683   139    34   105   119     0   357    0
vmsppl     488     3214    0     3184     5     0     5     5     0     8    0
rwobjpl     80    58538    0    51614   153     2   151   152     0     8    0
pdppl      4096    6438    0     6368   126    54    72    86     0     8    2
pvpl        32    24716    0        0   199     0   199   199     0   265    0
pmappl     256     3214    0     3184     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      353    0      100     8     0     8     8     0     8    0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
savectx() at savectx+0xae
end of kernel
end trace frame: 0x7638ce0ced40, count: -1
ddb{0}> machine ddbcpu 1
Stopped at      x86_ipi_db+0x27:        addq    $0x8,%rsp
x86_ipi_db(ffff8000299edff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
x86_bus_space_io_read_4(b008,0) at x86_bus_space_io_read_4+0x37 sys/arch/amd64/amd64/bus_space.c:666
acpitimer_delay(1) at acpitimer_delay+0x76 acpitimer_read sys/dev/acpi/acpitimer.c:142 [inline]
acpitimer_delay(1) at acpitimer_delay+0x76 sys/dev/acpi/acpitimer.c:120
comcnputc(800,30) at comcnputc+0x29b sys/dev/ic/com.c:1269
cnputc(30) at cnputc+0x67 sys/dev/cons.c:218
db_putchar(30) at db_putchar+0x36d sys/ddb/db_output.c:155
kprintf() at kprintf+0x29a5 sys/kern/subr_prf.c:-1
db_printf(ffffffff83347140) at db_printf+0x9b sys/kern/subr_prf.c:-1
panic(ffffffff83363e2c) at panic+0x103 sys/kern/subr_prf.c:217
pool_p_free(ffffffff839bb320,fffffd805eff6f90) at pool_p_free+0x2d1 sys/kern/subr_pool.c:986
pool_reclaim(ffffffff839bb320) at pool_reclaim+0x2c2 sys/kern/subr_pool.c:1152
pool_reclaim_all() at pool_reclaim_all+0x48 sys/kern/subr_pool.c:-1
end trace frame: 0xffff80003c4b3550, count: 0
ddb{1}> trace
x86_ipi_db(ffff8000299edff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
x86_bus_space_io_read_4(b008,0) at x86_bus_space_io_read_4+0x37 sys/arch/amd64/amd64/bus_space.c:666
acpitimer_delay(1) at acpitimer_delay+0x76 acpitimer_read sys/dev/acpi/acpitimer.c:142 [inline]
acpitimer_delay(1) at acpitimer_delay+0x76 sys/dev/acpi/acpitimer.c:120
comcnputc(800,30) at comcnputc+0x29b sys/dev/ic/com.c:1269
cnputc(30) at cnputc+0x67 sys/dev/cons.c:218
db_putchar(30) at db_putchar+0x36d sys/ddb/db_output.c:155
kprintf() at kprintf+0x29a5 sys/kern/subr_prf.c:-1
db_printf(ffffffff83347140) at db_printf+0x9b sys/kern/subr_prf.c:-1
panic(ffffffff83363e2c) at panic+0x103 sys/kern/subr_prf.c:217
pool_p_free(ffffffff839bb320,fffffd805eff6f90) at pool_p_free+0x2d1 sys/kern/subr_pool.c:986
pool_reclaim(ffffffff839bb320) at pool_reclaim+0x2c2 sys/kern/subr_pool.c:1152
pool_reclaim_all() at pool_reclaim_all+0x48 sys/kern/subr_pool.c:-1
kern_sysctl(ffff80003c4b3574,1,200000000180,ffff80003c4b35a8,200000001180,4,d99cfffc49365172) at kern_sysctl+0x1095 sys/kern/kern_sysctl.c:686
sys_sysctl(ffff800037810aa0,ffff80003c4b36e0,ffff80003c4b3630) at sys_sysctl+0x3e5 sys/kern/kern_sysctl.c:-1
syscall(ffff80003c4b36e0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4b36e0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:748
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x1200d9feb00, count: -18

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/08 06:03 openbsd ca647cfa4ec3 6a893178 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore panic: pool_p_free: rttmr free list modified: page ADDR; item addr ADDR; offset 0x10=ADDR
* Struck through repros no longer work on HEAD.