panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *283177 52329 0 0 0x4000000 1 syz-executor0 273719 8471 73 0x100010 0 0K syslogd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_warn(fda425885d33f84b,0,ffff800020b92978) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(fda425885d33f84b,0,ffff800020b92978) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(754a8085ea3f2735) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(9bad39093e209472) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(9bad39093e209472) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,0,ffffffffffffffbc,0,3,be8ea5201a0) at Xsyscall+0x128 end of kernel end trace frame: 0xbeaf8b9a830, count: 9 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}> show panic witness_warn ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_warn(fda425885d33f84b,0,ffff800020b92978) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(fda425885d33f84b,0,ffff800020b92978) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(754a8085ea3f2735) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(9bad39093e209472) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(9bad39093e209472) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,0,ffffffffffffffbc,0,3,be8ea5201a0) at Xsyscall+0x128 end of kernel end trace frame: 0xbeaf8b9a830, count: -6 ddb{1}> show registers rdi 0xffffffff81724177 db_enter+0x17 rsi 0x478e __ALIGN_SIZE+0x378e rbp 0xffff800020cdf670 rbx 0xffff800020cdf710 rdx 0x478f __ALIGN_SIZE+0x378f rcx 0xffff800000d46000 rax 0xffff800000d46000 r8 0xffffffff81d43064 kprintf+0x174 r9 0x1 r10 0x721703d7dbf337d3 r11 0xab083e3e6f10e3bc r12 0x3000000008 r13 0xffff800020cdf680 r14 0x100 r15 0x1 rip 0xffffffff81724178 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020cdf660 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor0) pid=283177 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b93080,0xffffffff822e8af0 process=0xffff800020b95a50 user=0xffff800020cda000, vmspace=0xfffffd807f00c438 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 52329 390847 35109 0 2 0 syz-executor0 52329 507639 35109 0 3 0x4000080 fsleep syz-executor0 52329 327578 35109 0 2 0x4000000 syz-executor0 *52329 283177 35109 0 7 0x4000000 syz-executor0 99360 359864 90285 0 2 0x480 syz-executor1 99360 72838 90285 0 3 0x4000080 netio syz-executor1 5878 70479 0 0 3 0x14200 bored sosplice 90285 518533 77098 0 2 0x482 syz-executor1 35109 258273 77098 0 2 0x482 syz-executor0 77098 348844 83866 0 3 0x82 thrsleep syz-fuzzer 77098 95015 83866 0 3 0x4000082 thrsleep syz-fuzzer 77098 51187 83866 0 3 0x4000082 thrsleep syz-fuzzer 77098 377397 83866 0 3 0x4000082 thrsleep syz-fuzzer 77098 373194 83866 0 3 0x4000082 thrsleep syz-fuzzer 77098 236182 83866 0 3 0x4000082 thrsleep syz-fuzzer 77098 456504 83866 0 3 0x4000082 thrsleep syz-fuzzer 77098 393747 83866 0 3 0x4000082 thrsleep syz-fuzzer 77098 185153 83866 0 3 0x4000082 kqread syz-fuzzer 77098 141905 83866 0 3 0x4000082 thrsleep syz-fuzzer 83866 300315 14479 0 3 0x10008a pause ksh 14479 50243 64862 0 3 0x92 select sshd 86839 139056 1 0 3 0x100083 ttyin getty 64862 191229 1 0 3 0x80 select sshd 8471 273719 3687 73 7 0x100010 syslogd 3687 393414 1 0 3 0x100082 netio syslogd 17376 250475 1 77 3 0x100090 poll dhclient 38268 178539 1 0 3 0x80 poll dhclient 26464 238920 0 0 3 0x14200 pgzero zerothread 32934 110903 0 0 3 0x14200 aiodoned aiodoned 73358 73511 0 0 3 0x14200 syncer update 53149 488862 0 0 3 0x14200 cleaner cleaner 26345 511316 0 0 3 0x14200 reaper reaper 51294 81813 0 0 3 0x14200 pgdaemon pagedaemon 19158 224310 0 0 3 0x14200 bored crynlk 4275 221231 0 0 3 0x14200 bored crypto 20675 128236 0 0 3 0x40014200 acpi0 acpi0 53937 273289 0 0 3 0x40014200 idle1 60293 91273 0 0 3 0x14200 bored softnet 82461 228629 0 0 3 0x14200 bored systqmp 69956 223735 0 0 3 0x14200 bored systq 62600 225644 0 0 3 0x40014200 bored softclock 38705 198902 0 0 3 0x40014200 idle0 1 288918 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 52329 (syz-executor0) thread 0xffff800020b92978 (283177) exclusive rrwlock inode r = 0 (0xfffffd806e68cd68) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 Process 8471 (syslogd) thread 0xffff800020be5c30 (273719) exclusive rrwlock inode r = 0 (0xfffffd806eb953c8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff822d2378) locked @ /syzkaller/managers/multicore/kernel/sys/sys/syscall_mi.h:90 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9484 6337K 6345K 78643K 10628 0 0 pcb 31 10K 10K 78643K 158 0 0 rtable 97 3K 3K 78643K 191 0 0 ifaddr 44 11K 11K 78643K 54 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 17 0 0 iov 0 0K 12K 78643K 22 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1194 75K 75K 78643K 1370 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 6 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 33 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 6 17K 25K 78643K 221 0 0 sigio 0 0K 0K 78643K 4 0 0 proc 41 38K 58K 78643K 292 0 0 subproc 64 65538K 67586K 78643K 68 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 18 0 0 in_multi 33 2K 2K 78643K 44 0 0 ether_multi 1 0K 0K 78643K 3 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 60 265K 265K 78643K 60 0 0 exec 0 0K 1K 78643K 184 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 82 20K 21K 78643K 1460 0 0 UVM aobj 6 2K 2K 78643K 6 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 9 0 0 NDP 8 0K 0K 78643K 15 0 0 temp 107 2350K 2420K 78643K 3284 0 0 kqueue 0 0K 0K 78643K 2 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 4 0 0 1 0 1 1 0 8 0 inpcbpl 280 113 0 106 1 0 1 1 0 8 0 plimitpl 152 17 0 9 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 41 0 1 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 38 0 38 1 1 0 1 0 8 0 tcpcb 544 34 0 30 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 185 0 0 12 0 12 12 0 8 0 art_table 32 186 0 0 2 0 2 2 0 8 0 art_node 16 40 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 2 1 1 0 1 0 8 0 semapl 112 30 0 20 1 0 1 1 0 8 0 shmpl 112 4 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1838 0 454 45 0 45 45 0 8 0 ffsino 272 1838 0 454 93 0 93 93 0 8 0 nchpl 144 2355 0 772 59 0 59 59 0 8 0 uvmvnodes 72 1901 0 0 35 0 35 35 0 8 0 vnodes 200 1901 0 0 101 0 101 101 0 8 0 namei 1024 6121 0 6121 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 9150 0 9149 9 6 3 6 0 8 2 sigapl 432 388 0 374 2 0 2 2 0 8 0 futexpl 56 2910 0 2909 1 0 1 1 0 8 0 knotepl 112 128 0 101 2 1 1 2 0 8 0 kqueuepl 104 78 0 74 1 0 1 1 0 8 0 pipepl 112 270 0 237 2 1 1 1 0 8 0 fdescpl 488 389 0 374 3 1 2 3 0 8 0 filepl 152 2457 0 2324 7 1 6 6 0 8 0 lockfpl 96 51 0 51 2 1 1 1 0 8 1 lockfspl 24 62 0 62 2 1 1 1 0 8 1 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 23 0 13 1 0 1 1 0 8 0 ucredpl 96 625 0 618 1 0 1 1 0 8 0 zombiepl 144 374 0 374 2 1 1 1 0 8 1 processpl 840 404 0 374 4 0 4 4 0 8 0 procpl 600 881 0 838 4 0 4 4 0 8 0 sosppl 128 3 0 3 1 0 1 1 0 8 1 sockpl 384 245 0 220 3 0 3 3 0 8 0 mcl64k 65536 228 0 0 29 0 29 29 0 8 1 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 3 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 116 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 305 0 0 19 0 19 19 0 8 0 bufpl 256 5376 0 981 275 0 275 275 0 8 0 anonpl 16 63560 0 56227 47 1 46 46 0 125 15 amapchunkpl 152 2139 0 2046 10 4 6 9 0 158 2 amappl16 192 2715 0 2335 42 15 27 31 0 8 8 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 6 0 3 2 1 1 1 0 8 0 amappl13 168 20 0 16 1 0 1 1 0 8 0 amappl12 160 23 0 21 1 0 1 1 0 8 0 amappl11 152 290 0 278 1 0 1 1 0 8 0 amappl10 144 61 0 57 1 0 1 1 0 8 0 amappl9 136 445 0 443 1 0 1 1 0 8 0 amappl8 128 139 0 120 1 0 1 1 0 8 0 amappl7 120 35 0 29 1 0 1 1 0 8 0 amappl6 112 45 0 39 1 0 1 1 0 8 0 amappl5 104 104 0 92 1 0 1 1 0 8 0 amappl4 96 383 0 356 2 1 1 2 0 8 0 amappl3 88 134 0 129 1 0 1 1 0 8 0 amappl2 80 2662 0 2600 2 0 2 2 0 8 0 amappl1 72 16550 0 16117 24 15 9 19 0 8 0 amappl 72 1094 0 1057 1 0 1 1 0 75 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma64 64 259 0 259 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 5 0 0 1 0 1 1 0 8 0 uaddrrnd 24 389 0 374 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 389 0 374 1 0 1 1 0 8 0 vmmpekpl 168 6910 0 6889 2 0 2 2 0 8 0 vmmpepl 168 55726 0 54313 86 17 69 73 0 357 7 vmsppl 360 388 0 374 2 0 2 2 0 8 0 pdppl 4096 785 0 748 6 1 5 6 0 8 0 pvpl 32 230804 0 220388 126 5 121 124 0 265 35 pmappl 224 388 0 374 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 459 0 3 14 0 14 14 0 8 0