panic: timeout_add: to_ticks (-2) < 0 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 315651 25314 0 0 0 0 syz-executor.0 * 41853 25314 0 0 0x4000000 1K syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x174 sys/kern/subr_prf.c:208 timeout_add(ffff80000066d060,fffffffe) at timeout_add+0x194 sys/kern/kern_timeout.c:190 pcppi_bell(ffff80000066d000,4,fffffffe,1) at pcppi_bell+0x2a0 sys/dev/isa/pcppi.c:234 spkrioctl(1b00,20005302,ffff800020c22f40,2,ffff800020b42978) at spkrioctl+0x230 tone sys/dev/isa/spkr.c:89 [inline] spkrioctl(1b00,20005302,ffff800020c22f40,2,ffff800020b42978) at spkrioctl+0x230 sys/dev/isa/spkr.c:503 VOP_IOCTL(fffffd8075476210,20005302,ffff800020c22f40,2,fffffd807f7c7a20,ffff800020b42978) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd806ea53db0,20005302,ffff800020c22f40,ffff800020b42978) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42978,ffff800020c23088,ffff800020c23070) at sys_ioctl+0x646 syscall(ffff800020c23120) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c23120) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff88,0,3,cab18984010) at Xsyscall+0x128 end of kernel end trace frame: 0xcad8f23a1b0, count: 5 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 timeout_add: to_ticks (-2) < 0 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x174 sys/kern/subr_prf.c:208 timeout_add(ffff80000066d060,fffffffe) at timeout_add+0x194 sys/kern/kern_timeout.c:190 pcppi_bell(ffff80000066d000,4,fffffffe,1) at pcppi_bell+0x2a0 sys/dev/isa/pcppi.c:234 spkrioctl(1b00,20005302,ffff800020c22f40,2,ffff800020b42978) at spkrioctl+0x230 tone sys/dev/isa/spkr.c:89 [inline] spkrioctl(1b00,20005302,ffff800020c22f40,2,ffff800020b42978) at spkrioctl+0x230 sys/dev/isa/spkr.c:503 VOP_IOCTL(fffffd8075476210,20005302,ffff800020c22f40,2,fffffd807f7c7a20,ffff800020b42978) at VOP_IOCTL+0x9a sys/kern/vfs_vops.c:290 vn_ioctl(fffffd806ea53db0,20005302,ffff800020c22f40,ffff800020b42978) at vn_ioctl+0xc9 sys/kern/vfs_vnops.c:512 sys_ioctl(ffff800020b42978,ffff800020c23088,ffff800020c23070) at sys_ioctl+0x646 syscall(ffff800020c23120) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c23120) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,ffffffffffffff88,0,3,cab18984010) at Xsyscall+0x128 end of kernel end trace frame: 0xcad8f23a1b0, count: -10 ddb{1}> show registers rdi 0xffffffff81264217 db_enter+0x17 rsi 0xd3b rbp 0xffff800020c22b60 rbx 0xffff800020c22c10 rdx 0xd3c rcx 0xffff800000947000 rax 0xffff800000947000 r8 0xffffffff81316553 kprintf+0x183 r9 0x1 r10 0x25 r11 0xc94d861835d057aa r12 0x3000000008 r13 0xffff800020c22b70 r14 0x100 r15 0x1 rip 0xffffffff81264218 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c22b50 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=41853 stat=onproc flags process=0 proc=4000000 pri=81, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff800020b42018,0xffffffff82334d38 process=0xffff800020b44d30 user=0xffff800020c1e000, vmspace=0xfffffd807f00d168 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 25314 315651 22788 0 7 0 syz-executor.0 *25314 41853 22788 0 7 0x4000000 syz-executor.0 19609 512595 1 0 3 0x100083 ttyin getty 48652 281059 0 0 3 0x14200 bored sosplice 96063 380967 3696 0 3 0x82 nanosleep syz-executor.1 22788 406289 3696 0 3 0x82 nanosleep syz-executor.0 3696 449211 95957 0 3 0x82 thrsleep syz-fuzzer 3696 499654 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 139861 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 122579 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 137377 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 508345 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 178216 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 230898 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 430261 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 17723 95957 0 3 0x4000082 thrsleep syz-fuzzer 3696 183125 95957 0 3 0x4000082 kqread syz-fuzzer 95957 96708 4803 0 3 0x10008a pause ksh 4803 160776 83822 0 3 0x92 select sshd 83822 119210 1 0 3 0x80 select sshd 65949 60161 26587 73 3 0x100090 kqread syslogd 26587 342517 1 0 3 0x100082 netio syslogd 93899 466644 1 77 3 0x100090 poll dhclient 83391 422509 1 0 3 0x80 poll dhclient 55062 322918 0 0 3 0x14200 pgzero zerothread 77467 56957 0 0 3 0x14200 aiodoned aiodoned 42850 174823 0 0 3 0x14200 syncer update 98867 51929 0 0 3 0x14200 cleaner cleaner 83738 6862 0 0 3 0x14200 reaper reaper 75871 382222 0 0 3 0x14200 pgdaemon pagedaemon 97160 189144 0 0 3 0x14200 bored crynlk 45510 427324 0 0 3 0x14200 bored crypto 20630 33875 0 0 3 0x40014200 acpi0 acpi0 20999 30486 0 0 3 0x40014200 idle1 13940 476743 0 0 3 0x14200 bored softnet 67059 36539 0 0 3 0x14200 bored systqmp 89070 444100 0 0 3 0x14200 bored systq 3650 519035 0 0 3 0x40014200 bored softclock 1095 380117 0 0 3 0x40014200 idle0 1 441045 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 25314 (syz-executor.0) thread 0xffff800020b42978 (41853) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8235c720) locked @ /syzkaller/managers/multicore/kernel/sys/sys/syscall_mi.h:90 #0 witness_lock+0x58a sys/kern/subr_witness.c:1205 #1 syscall+0x47f mi_syscall sys/sys/syscall_mi.h:91 [inline] #1 syscall+0x47f sys/arch/amd64/amd64/trap.c:574 #2 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9521 6365K 6380K 78643K 11120 0 0 pcb 23 9K 11K 78643K 827 0 0 rtable 100 3K 4K 78643K 471 0 0 ifaddr 54 13K 13K 78643K 219 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 31 0 0 iov 0 0K 20K 78643K 217 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1185 74K 75K 78643K 1942 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 22 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 195 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 25K 78643K 1529 0 0 sigio 0 0K 0K 78643K 21 0 0 proc 43 38K 70K 78643K 503 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 217 0 0 in_multi 33 2K 2K 78643K 108 0 0 ether_multi 1 0K 0K 78643K 10 0 0 mrt 0 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 90 397K 397K 78643K 90 0 0 exec 0 0K 1K 78643K 303 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 86 21K 30K 78643K 5715 0 0 UVM aobj 90 3K 3K 78643K 96 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 51 0 0 NDP 11 0K 0K 78643K 61 0 0 temp 163 2367K 3003K 78643K 6936 0 0 kqueue 0 0K 0K 78643K 11 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 280 769 0 762 2 1 1 2 0 8 0 plimitpl 152 33 0 26 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 tcpcb 544 271 0 267 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 30 0 30 7 7 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 186 0 0 12 0 12 12 0 8 0 art_table 32 187 0 0 2 0 2 2 0 8 0 art_node 16 40 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 16 0 0 1 0 1 1 0 8 0 semapl 112 193 0 183 1 0 1 1 0 8 0 shmpl 112 94 0 6 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4241 0 2820 46 0 46 46 0 8 0 ffsino 272 4241 0 2820 96 0 96 96 0 8 0 nchpl 144 6659 0 5036 61 0 61 61 0 8 0 uvmvnodes 72 4419 0 0 81 0 81 81 0 8 0 vnodes 200 4419 0 0 233 0 233 233 0 8 0 namei 1024 20406 0 20406 3 2 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 20729 0 20729 13 12 1 6 0 8 1 sigapl 432 1700 0 1687 2 0 2 2 0 8 0 futexpl 56 19067 0 19067 1 0 1 1 0 8 1 knotepl 112 414 0 387 3 2 1 2 0 8 0 kqueuepl 104 501 0 499 1 0 1 1 0 8 0 pipepl 112 1184 0 1165 6 5 1 2 0 8 0 fdescpl 488 1701 0 1687 3 1 2 3 0 8 0 filepl 152 10519 0 10424 11 6 5 6 0 8 1 lockfpl 104 450 0 449 4 3 1 1 0 8 0 lockfspl 32 387 0 386 4 3 1 1 0 8 0 sessionpl 112 20 0 10 1 0 1 1 0 8 0 pgrppl 48 38 0 28 1 0 1 1 0 8 0 ucredpl 96 2816 0 2809 1 0 1 1 0 8 0 zombiepl 144 1687 0 1686 2 1 1 1 0 8 0 processpl 840 1716 0 1686 4 0 4 4 0 8 0 procpl 600 5046 0 5005 4 0 4 4 0 8 0 sosppl 128 19 0 19 5 4 1 1 0 8 1 sockpl 384 1473 0 1456 7 4 3 4 0 8 1 mcl64k 65536 593 0 0 72 9 63 65 0 8 0 mcl16k 16384 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 6 0 0 1 0 1 1 0 8 0 mcl9k 9216 11 0 0 1 0 1 1 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 125 0 0 15 0 15 15 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 690 0 0 37 0 37 37 0 8 0 bufpl 256 8453 0 1481 436 0 436 436 0 8 0 anonpl 16 186875 0 178884 88 39 49 49 0 125 14 amapchunkpl 152 9868 0 9782 27 18 9 9 0 158 4 amappl16 192 8833 0 8412 93 63 30 34 0 8 8 amappl15 184 749 0 748 2 1 1 1 0 8 0 amappl14 176 760 0 756 2 1 1 1 0 8 0 amappl13 168 27 0 24 1 0 1 1 0 8 0 amappl12 160 772 0 768 2 1 1 1 0 8 0 amappl11 152 184 0 174 1 0 1 1 0 8 0 amappl10 144 62 0 59 2 1 1 1 0 8 0 amappl9 136 331 0 328 1 0 1 1 0 8 0 amappl8 128 913 0 890 1 0 1 1 0 8 0 amappl7 120 39 0 33 1 0 1 1 0 8 0 amappl6 112 812 0 802 1 0 1 1 0 8 0 amappl5 104 178 0 167 1 0 1 1 0 8 0 amappl4 96 294 0 273 2 1 1 2 0 8 0 amappl3 88 208 0 203 1 0 1 1 0 8 0 amappl2 80 15084 0 15034 2 0 2 2 0 8 0 amappl1 72 46093 0 45671 24 14 10 19 0 8 0 amappl 72 5274 0 5241 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 95 0 6 2 0 2 2 0 8 0 uaddrrnd 24 1701 0 1687 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1701 0 1687 1 0 1 1 0 8 0 vmmpekpl 168 17154 0 17133 2 0 2 2 0 8 0 vmmpepl 168 187694 0 186319 124 49 75 75 0 357 10 vmsppl 360 1700 0 1687 2 0 2 2 0 8 0 pdppl 4096 3409 0 3374 6 1 5 6 0 8 0 pvpl 32 499582 0 488606 204 81 123 133 0 265 33 pmappl 224 1700 0 1687 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 687 0 14 20 0 20 20 0 8 0