panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 325932 13668 0 0 0 1 syz-executor0 * 8613 13668 0 0 0x4000000 0 syz-executor0 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(3992c34bb51d4af1,0,ffff800020b92bd0) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(3992c34bb51d4af1,0,ffff800020b92bd0) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(d42609317168fec) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(c20f9ea47e7d1609) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(c20f9ea47e7d1609) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,2a84a2301a0) at Xsyscall+0x128 end of kernel end trace frame: 0x2aa8716a5f0, 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{0}> ddb{0}> set $lines = 0 ddb{0}> show panic witness_warn ddb{0}> 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(3992c34bb51d4af1,0,ffff800020b92bd0) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(3992c34bb51d4af1,0,ffff800020b92bd0) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(d42609317168fec) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(c20f9ea47e7d1609) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(c20f9ea47e7d1609) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,2a84a2301a0) at Xsyscall+0x128 end of kernel end trace frame: 0x2aa8716a5f0, count: -6 ddb{0}> show registers rdi 0xffffffff8137f4d7 db_enter+0x17 rsi 0x4f86 __ALIGN_SIZE+0x3f86 rbp 0xffff800020c9b550 rbx 0xffff800020c9b5f0 rdx 0x4f87 __ALIGN_SIZE+0x3f87 rcx 0xffff800000d46000 rax 0xffff800000d46000 r8 0xffffffff81949104 kprintf+0x174 r9 0x1 r10 0x649e64e082e1c1b6 r11 0x3df0615bff97873d r12 0x3000000008 r13 0xffff800020c9b560 r14 0x100 r15 0x1 rip 0xffffffff8137f4d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c9b540 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor0) pid=8613 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=63, nice=20 forw=0xffffffffffffffff, list=0xffff800020b92720,0xffff800020b93090 process=0xffff800020b95a50 user=0xffff800020c96000, vmspace=0xfffffd807f00d9d8 estcpu=13, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 13668 325932 99451 0 7 0 syz-executor0 13668 215506 99451 0 3 0x4000080 ttyin syz-executor0 13668 190818 99451 0 2 0x4000000 syz-executor0 *13668 8613 99451 0 7 0x4000000 syz-executor0 13668 277710 99451 0 2 0x4000000 syz-executor0 13668 91636 99451 0 3 0x4000000 inode syz-executor0 83502 511075 1 0 3 0x100083 ttyin getty 29701 137269 0 0 3 0x14200 bored sosplice 89073 352163 18517 0 3 0x82 piperd syz-executor1 99451 166572 18517 0 3 0x82 nanosleep syz-executor0 18517 177122 52742 0 3 0x82 thrsleep syz-fuzzer 18517 233515 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 116984 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 205921 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 270519 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 129355 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 114474 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 239991 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 501767 52742 0 3 0x4000082 thrsleep syz-fuzzer 18517 506264 52742 0 3 0x4000082 kqread syz-fuzzer 52742 25793 30829 0 3 0x10008a pause ksh 30829 224677 20920 0 3 0x92 select sshd 20920 97533 1 0 3 0x80 select sshd 720 33786 87819 73 3 0x100010 biowait syslogd 87819 204308 1 0 3 0x100082 netio syslogd 10201 41225 1 77 3 0x100090 poll dhclient 82282 266550 1 0 3 0x80 poll dhclient 21860 365913 0 0 3 0x14200 pgzero zerothread 58492 469356 0 0 3 0x14200 aiodoned aiodoned 38723 442220 0 0 3 0x14200 syncer update 37046 335330 0 0 3 0x14200 cleaner cleaner 5213 279896 0 0 3 0x14200 reaper reaper 7279 134676 0 0 3 0x14200 pgdaemon pagedaemon 58839 250886 0 0 3 0x14200 bored crynlk 63745 257136 0 0 3 0x14200 bored crypto 79118 234987 0 0 3 0x40014200 acpi0 acpi0 29647 172453 0 0 3 0x40014200 idle1 70842 90071 0 0 3 0x14200 bored softnet 72943 322500 0 0 3 0x14200 bored systqmp 20830 434886 0 0 3 0x14200 bored systq 15407 125061 0 0 3 0x40014200 bored softclock 78834 50588 0 0 3 0x40014200 idle0 1 85110 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 13668 (syz-executor0) thread 0xffff800020b92bd0 (8613) exclusive rrwlock inode r = 0 (0xfffffd8077bbe0a8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 Process 720 (syslogd) thread 0xffff800020be5c30 (33786) exclusive rrwlock inode r = 0 (0xfffffd806ebbc4d8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9490 6340K 6348K 78643K 10634 0 0 pcb 23 9K 10K 78643K 196 0 0 rtable 97 3K 3K 78643K 185 0 0 ifaddr 44 11K 11K 78643K 51 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 17 0 0 iov 0 0K 16K 78643K 41 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1197 75K 75K 78643K 1381 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 9 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 28 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 25K 78643K 283 0 0 proc 42 38K 70K 78643K 290 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 42 0 0 in_multi 33 2K 2K 78643K 39 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 177 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 81 20K 29K 78643K 1606 0 0 UVM aobj 26 2K 2K 78643K 26 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 8 0 0 NDP 8 0K 0K 78643K 14 0 0 temp 115 2357K 2421K 78643K 3455 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> 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 280 154 0 147 1 0 1 1 0 8 0 plimitpl 152 16 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 44 0 44 1 1 0 1 0 8 0 tcpcb 544 48 0 44 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 9 0 6 1 0 1 1 0 8 0 semapl 112 26 0 16 1 0 1 1 0 8 0 shmpl 112 24 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1947 0 559 45 0 45 45 0 8 0 ffsino 272 1947 0 559 93 0 93 93 0 8 0 nchpl 144 2546 0 962 59 0 59 59 0 8 0 uvmvnodes 72 2021 0 0 37 0 37 37 0 8 0 vnodes 200 2021 0 0 107 0 107 107 0 8 0 namei 1024 6608 0 6608 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 2 0 2 1 1 0 1 0 8 0 scxspl 192 7091 0 7090 10 9 1 6 0 8 0 sigapl 432 451 0 438 2 0 2 2 0 8 0 futexpl 56 3549 0 3549 1 0 1 1 0 8 1 knotepl 112 113 0 85 2 1 1 2 0 8 0 kqueuepl 104 71 0 68 1 0 1 1 0 8 0 pipepl 112 246 0 227 2 1 1 1 0 8 0 fdescpl 488 452 0 438 3 1 2 3 0 8 0 filepl 152 2650 0 2543 6 1 5 5 0 8 0 lockfpl 96 74 0 74 2 1 1 1 0 8 1 lockfspl 24 82 0 82 2 1 1 1 0 8 1 sessionpl 112 18 0 8 1 0 1 1 0 8 0 pgrppl 48 20 0 10 1 0 1 1 0 8 0 ucredpl 96 672 0 665 1 0 1 1 0 8 0 zombiepl 144 438 0 438 2 1 1 1 0 8 1 processpl 840 467 0 438 4 0 4 4 0 8 0 procpl 600 1029 0 986 4 0 4 4 0 8 0 sosppl 128 6 0 6 2 1 1 1 0 8 1 sockpl 384 323 0 306 3 0 3 3 0 8 1 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 5 0 0 1 0 1 1 0 8 0 mcl4k 4096 7 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 120 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 149 0 0 9 0 9 9 0 8 0 bufpl 256 5722 0 967 298 0 298 298 0 8 0 anonpl 16 61707 0 54644 48 12 36 47 0 125 7 amapchunkpl 152 2473 0 2379 10 4 6 9 0 158 1 amappl16 192 2569 0 2202 34 11 23 32 0 8 4 amappl15 184 2 0 0 1 0 1 1 0 8 0 amappl14 176 139 0 136 2 1 1 1 0 8 0 amappl13 168 19 0 16 1 0 1 1 0 8 0 amappl12 160 18 0 17 1 0 1 1 0 8 0 amappl11 152 182 0 173 1 0 1 1 0 8 0 amappl10 144 62 0 59 1 0 1 1 0 8 0 amappl9 136 340 0 339 1 0 1 1 0 8 0 amappl8 128 139 0 120 1 0 1 1 0 8 0 amappl7 120 36 0 30 1 0 1 1 0 8 0 amappl6 112 185 0 177 1 0 1 1 0 8 0 amappl5 104 122 0 111 1 0 1 1 0 8 0 amappl4 96 414 0 388 2 1 1 2 0 8 0 amappl3 88 132 0 127 1 0 1 1 0 8 0 amappl2 80 3165 0 3112 2 0 2 2 0 8 0 amappl1 72 17959 0 17530 24 14 10 19 0 8 0 amappl 72 1241 0 1204 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 25 0 0 1 0 1 1 0 8 0 uaddrrnd 24 452 0 438 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 452 0 438 1 0 1 1 0 8 0 vmmpekpl 168 7082 0 7061 2 0 2 2 0 8 0 vmmpepl 168 54960 0 53640 87 21 66 72 0 357 6 vmsppl 360 451 0 438 2 0 2 2 0 8 0 pdppl 4096 911 0 876 6 1 5 6 0 8 0 pvpl 32 184123 0 174037 133 20 113 125 0 265 28 pmappl 224 451 0 438 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 443 0 3 13 0 13 13 0 8 0