syzbot


uvm_fault: ffs_freefile (3)

Status: upstream: reported on 2026/03/27 23:15
Reported-by: syzbot+0ed6c58abf4b6f542e62@syzkaller.appspotmail.com
First crash: 60d, last: 1d14h
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd uvm_fault: ffs_freefile (2) -1 1 256d 256d 0/3 auto-obsoleted due to no activity on 2025/12/12 07:10
openbsd uvm_fault: ffs_freefile -1 2 619d 621d 0/3 auto-obsoleted due to no activity on 2024/12/13 12:31

Sample crash report:
uvm_fault(0xffffffff83b11080, 0xffff800020742004, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ffs_freefile+0x11e:     movl    0x4(%rbx),%r13d
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*202042   9543      0         0x2          0    1K syz-executor
 139232  67481      0         0x2        0x1    0  syz-executor
ffs_freefile(fffffd80721ae850,cbff,6000) at ffs_freefile+0x11e ffs_cgread sys/ufs/ffs/ffs_alloc.c:856 [inline]
ffs_freefile(fffffd80721ae850,cbff,6000) at ffs_freefile+0x11e sys/ufs/ffs/ffs_alloc.c:1377
ffs_inode_free(fffffd80721ae850,cbff,6000) at ffs_inode_free+0x44 sys/ufs/ffs/ffs_alloc.c:1355
ufs_inactive(ffff80002a2e4ac0) at ufs_inactive+0x29c sys/ufs/ufs/ufs_inode.c:94
VOP_INACTIVE(fffffd805f661ca8,ffff80002a222a70) at VOP_INACTIVE+0x104 sys/kern/vfs_vops.c:498
vput(fffffd805f661ca8) at vput+0xe5 sys/kern/vfs_subr.c:789
VOP_REMOVE(fffffd806c628648,fffffd805f661ca8,ffff80002a2e4c28) at VOP_REMOVE+0x199 sys/kern/vfs_vops.c:336
dounlinkat(ffff80002a222a70,ffffff9c,7b2b71d46be0,0) at dounlinkat+0x1c4 sys/kern/vfs_syscalls.c:1929
syscall(ffff80002a2e4da0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2e4da0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7b2b71d47090, count: 6
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{1}> 
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: uvm_fault(0xffffffff83b11080, 0xffff800020742004, 0, 1) -> d
ddb{1}> trace
ffs_freefile(fffffd80721ae850,cbff,6000) at ffs_freefile+0x11e ffs_cgread sys/ufs/ffs/ffs_alloc.c:856 [inline]
ffs_freefile(fffffd80721ae850,cbff,6000) at ffs_freefile+0x11e sys/ufs/ffs/ffs_alloc.c:1377
ffs_inode_free(fffffd80721ae850,cbff,6000) at ffs_inode_free+0x44 sys/ufs/ffs/ffs_alloc.c:1355
ufs_inactive(ffff80002a2e4ac0) at ufs_inactive+0x29c sys/ufs/ufs/ufs_inode.c:94
VOP_INACTIVE(fffffd805f661ca8,ffff80002a222a70) at VOP_INACTIVE+0x104 sys/kern/vfs_vops.c:498
vput(fffffd805f661ca8) at vput+0xe5 sys/kern/vfs_subr.c:789
VOP_REMOVE(fffffd806c628648,fffffd805f661ca8,ffff80002a2e4c28) at VOP_REMOVE+0x199 sys/kern/vfs_vops.c:336
dounlinkat(ffff80002a222a70,ffffff9c,7b2b71d46be0,0) at dounlinkat+0x1c4 sys/kern/vfs_syscalls.c:1929
syscall(ffff80002a2e4da0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2e4da0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7b2b71d47090, count: -9
ddb{1}> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a2e4a00
rbx               0xffff800020742000
rdx                                0
rcx               0xffff80002a222a70
rax               0xfffffd8072051358
r8                0xffffffffffffffff
r9                0xfffffd80097fd478
r10               0xd72792e303cf9822
r11                0xf6e85d57fe86cec
r12                              0x2
r13                                0
r14               0xffff800000c31800
r15                           0xcbff    __ALIGN_SIZE+0xbbff
rip               0xffffffff8123e27e    ffs_freefile+0x11e
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80002a2e4970
ss                              0x10
ffs_freefile+0x11e:     movl    0x4(%rbx),%r13d
ddb{1}> show proc
PROC (syz-executor) tid=202042 pid=9543 tcnt=1 stat=onproc
    flags process=2<EXEC> proc=0
    runpri=32, usrpri=50, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a2227d8,0xffff80002a222550
    process=0xffff8000ffff4e78 user=0xffff80002a2df000, vmspace=0xfffffd800b063988
    estcpu=36, cpticks=9, pctcpu=0.0, user=0, sys=8, intr=0
ddb{1}> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 83997   83866  28597      0  2           0                syz-executor
 83997   65218  28597      0  3   0x4000080  fsleep        syz-executor
 33924   13054  92173      0  2           0                syz-executor
 33924  304821  92173      0  3   0x4000080  fsleep        syz-executor
 78546  415118  13829      0  2           0                syz-executor
 78546  247290  13829      0  2   0x4000000                syz-executor
 23221  405565  59235      0  2           0                syz-executor
 23221   59640  59235      0  3   0x4000080  fsleep        syz-executor
 17609  181495  19797      0  2           0                syz-executor
 17609  330788  19797      0  3   0x4000080  fsleep        syz-executor
 18333  115898  47401      0  3        0x80  nanoslp       syz-executor
 18333  214937  47401      0  3   0x4000080  sbwait        syz-executor
 18333  369295  47401      0  3   0x4000080  fsleep        syz-executor
 90531   20866      1      0  3        0x82  nanoslp       getty
 98437  105908      0      0  3     0x14280  nfsidl        nfsio
 78512  511034      0      0  3     0x14280  nfsidl        nfsio
 93030  216749      0      0  3     0x14280  nfsidl        nfsio
 93605  330732      0      0  3     0x14280  nfsidl        nfsio
 83902   19912      0      0  3     0x14280  nfsidl        nfsio
 19525  281546      0      0  3     0x14280  nfsidl        nfsio
 58295  114647      0      0  3     0x14280  nfsidl        nfsio
 48124    5250      0      0  3     0x14280  nfsidl        nfsio
 91944  323375      0      0  3     0x14280  nfsidl        nfsio
 46501  280924      0      0  3     0x14280  nfsidl        nfsio
 43672  135195      0      0  3     0x14280  nfsidl        nfsio
 35679  293825      0      0  3     0x14280  nfsidl        nfsio
 12269  250231      0      0  3     0x14280  nfsidl        nfsio
 60832  212499      0      0  3     0x14280  nfsidl        nfsio
 63548  227795      0      0  3     0x14280  nfsidl        nfsio
 12937  466649      0      0  3     0x14280  nfsidl        nfsio
 60503  290336      0      0  3     0x14280  nfsidl        nfsio
 87656   27735      0      0  3     0x14280  nfsidl        nfsio
 30142  518887      0      0  3     0x14280  nfsidl        nfsio
 86237   36702      0      0  3     0x14280  nfsidl        nfsio
 92173  264354  67481      0  3        0x82  nanoslp       syz-executor
 47401  299763  67481      0  3        0x82  nanoslp       syz-executor
 97035  392774  67481      0  3        0x82  nanoslp       syz-executor
 59235  331381  67481      0  3        0x82  nanoslp       syz-executor
 19797  354793  67481      0  3        0x82  nanoslp       syz-executor
* 9543  202042  67481      0  7         0x2                syz-executor
 28597  401251  67481      0  3        0x82  nanoslp       syz-executor
 13829   62819  67481      0  3        0x82  nanoslp       syz-executor
 67481  139232      1      0  7         0x3                syz-executor
 69128  325306      0      0  3     0x14200  bored         smr
 69327  433283      0      0  2     0x14200                zerothread
 53137  323893      0      0  3     0x14200  aiodoned      aiodoned
 86687  208681      0      0  3     0x14200  syncer        update
 40293  521971      0      0  3     0x14200  cleaner       cleaner
 27991  520992      0      0  3     0x14200  reaper        reaper
  3748  154681      0      0  3     0x14200  pgdaemon      pagedaemon
  7198  239495      0      0  3     0x14200  bored         viomb
 42207   90350      0      0  3  0x40014200  acpi0         acpi0
 78156   66622      0      0  3  0x40014200                idle1
 63587  293615      0      0  3     0x14200  bored         softnet1
 97758   86365      0      0  3     0x14200  bored         softnet0
 99181   52789      0      0  3     0x14200  bored         systqmp
  2237  490357      0      0  3     0x14200  bored         systq
  6398  312379      0      0  3     0x14200  tmoslp        softclockmp
 17661  183889      0      0  3  0x40014200  tmoslp        softclock
 35442  359177      0      0  3  0x40014200                idle0
     1  106053      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb{1}> show all locks
Process 9543 (syz-executor) thread 0xffff80002a222a70 (202042)
exclusive rrwlock inode r = 0 (0xfffffd80721ae8f0)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2  rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3  VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4  vn_lock+0xa4 sys/kern/vfs_vnops.c:576
#5  vget+0x2a2 sys/kern/vfs_subr.c:686
#6  ufs_ihashget+0x185 sys/ufs/ufs/ufs_ihash.c:98
#7  ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1203
#8  ufs_lookup+0x1a36 sys/ufs/ufs/ufs_lookup.c:478
#9  VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
#10 vfs_lookup+0x963 sys/kern/vfs_lookup.c:580
#11 namei+0x7c5 sys/kern/vfs_lookup.c:250
#12 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1893
#13 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#13 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
#14 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffffd80675e6570)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2  rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3  VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4  vn_lock+0xa4 sys/kern/vfs_vnops.c:576
#5  vget+0x2a2 sys/kern/vfs_subr.c:686
#6  cache_lookup+0x351 sys/kern/vfs_cache.c:222
#7  ufs_lookup+0x1e3 sys/ufs/ufs/ufs_lookup.c:160
#8  VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
#9  vfs_lookup+0x963 sys/kern/vfs_lookup.c:580
#10 namei+0x7c5 sys/kern/vfs_lookup.c:250
#11 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1893
#12 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#12 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
#13 Xsyscall+0x128
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83a6adc0)
#0  witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0  witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1  syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline]
#1  syscall+0xaf4 sys/arch/amd64/amd64/trap.c:783
#2  Xsyscall+0x128
ddb{1}> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 11084  12032K   12346K 166960K     12668        0
            pcb    19     13K      13K 166960K        65        0
         rtable   215      6K       7K 166960K       364        0
             pf    38     18K      24K 166960K        82        0
         ifaddr    43      7K       7K 166960K        54        0
        ifgroup    60      2K       2K 166960K        77        0
         sysctl     4      1K       9K 166960K         9        0
       counters    72     37K      37K 166960K        84        0
       ioctlops     0      0K       4K 166960K      1524        0
            iov     0      0K      12K 166960K        11        0
          mount     1      1K       1K 166960K         1        0
            log     2      4K       4K 166960K         6        0
         vnodes  1358     85K      86K 166960K      1691        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     2      1K      13K 166960K        13        0
         VM map     2      1K       1K 166960K         2        0
            sem     9      0K       0K 166960K        18        0
        dirhash    12      2K       2K 166960K        12        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    16     61K      89K 166960K       380        0
          sigio     0      0K       0K 166960K         4        0
           proc    21     33K     164K 166960K       605        0
        subproc    72      4K       4K 166960K        72        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K        33        0
       in_multi    96      7K       7K 166960K       103        0
    ether_multi     1      0K       0K 166960K         3        0
            mrt     0      0K       0K 166960K        10        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   241   1076K    1076K 166960K       241        0
           exec     0      0K       1K 166960K       442        0
   fusefs mount     1     32K      32K 166960K         1        0
     pfkey data     0      0K       0K 166960K         1        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   132     82K     185K 166960K      5305        0
       UVM aobj    16      2K       2K 166960K        16        0
     pinsyscall    19     38K     104K 166960K      1544        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K         4        0
            NDP    13      0K       2K 166960K        36        0
           temp    43   9115K    9206K 166960K     10532        0
         kqueue     1      2K      22K 166960K        58        0
      SYN cache     2     16K      16K 166960K         2        0
ddb{1}> 

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/25 17:34 openbsd 61b7e18e5713 c69befb3 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore uvm_fault: ffs_freefile
2026/05/24 22:26 openbsd 6adc68a286a5 c69befb3 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: ffs_freefile
2026/03/27 23:14 openbsd f3ad7971a235 4b3d9a38 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: ffs_freefile
* Struck through repros no longer work on HEAD.