panic: trap type 4, code=0, pc=ffffffff8152e645 Starting stack trace... panic(ffffffff834f0256) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff80002af92e70) at kerntrap+0x30b alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b malloc(10,7f,1) at malloc+0x855 sys/kern/kern_malloc.c:294 spec_open_clone(ffff80002af930e8) at spec_open_clone+0x333 sys/kern/spec_vnops.c:-1 spec_open(ffff80002af930e8) at spec_open+0x319 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffc806edb01b8,3,fffffc80097fd7b8,ffff800038b9c2c0) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138 vn_open(ffff80002af93338,3,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183 doopenat(ffff800038b9c2c0,ffffff9c,79e7d2e54e1,2,0,0,6e19f73574dee0b5) at doopenat+0x35b sys/kern/vfs_syscalls.c:1163 sys_open(ffff800038b9c2c0,ffff80002af935f0,ffff80002af93540) at sys_open+0x59 sys/kern/vfs_syscalls.c:1065 syscall(ffff80002af935f0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002af935f0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x72150c0ffea0, count: 245 End of stack trace. syncing disks...53 42 done WARNING: SPL NOT LOWERED ON SYSCALL 91 84045400 EXIT 0 a Stopped at savectx+0xae: movl $0,%gs:0x688 TID PID UID PRFLAGS PFLAGS CPU COMMAND * 63265 72875 0 0x2 0 1 syz-executor 465961 15698 0 0x14000 0x40000200 0 softclock savectx() at savectx+0xae end of kernel end trace frame: 0x788b05026e40, 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{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: trap type 4, code=0, pc=ffffffff8152e645 ddb{1}> show kasan No such command ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x788b05026e40, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff80002a2fcb00 rbx 0 rdx 0 rcx 0xffff80002a22a2b0 rax 0x39 r8 0xffff80002a2fca30 r9 0x1 r10 0xae4cccce25232199 r11 0x32e424b868e30f5 r12 0 r13 0 r14 0xffff80002a22a2b0 r15 0 rip 0xffffffff810563ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff80002a2fca80 ss 0x10 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=63265 pid=72875 tcnt=1 stat=onproc flags process=2 proc=0 runpri=32, usrpri=66, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a22a7e0,0xffff80002a22ba18 process=0xffff800045fed358 user=0xffff80002a2f7000, vmspace=0xfffffc800f98d3f0 estcpu=16, cpticks=7, pctcpu=0.1, user=0, sys=7, intr=0 ddb{1}> ps PID TID PPID UID S PRLAGS PFLAGS WAIT COMMAND 90170 405382 22429 0 3 0x2 0 sbar syz-executor 80428 199768 22429 0 3 0x2 0x80 piperd syz-executor 69071 200835 22429 0 3 0x2 0x80 piperd syz-executor *72875 63265 22429 0 7 0x2 0 syz-executor 63626 332616 1 0 2 0x100003 0x80 getty 24126 45020 22429 0 3 0x2 0x80 wait syz-executor 22429 445840 66006 0 3 0x2 0x80 wait syz-executor 66006 230798 72369 0 3 0x100002 0x88 sigsusp ksh 72369 397212 36795 0 3 0x10 0x88 kqread sshd-session 36795 141343 57928 0 3 0x12 0x80 kqread sshd-session 57928 76175 1 0 3 0 0x88 kqread sshd 9984 371795 48350 74 3 0x1100012 0x80 bpf pflogd 48350 418284 1 0 3 0 0x80 sbwait pflogd 1086 292561 18302 73 2 0x1100010 0 syslogd 18302 434126 1 0 3 0x100002 0x80 sbwait syslogd 84974 258192 1 0 3 0x100000 0x80 kqread resolvd 70988 287366 2474 77 3 0x100012 0x80 kqread dhcpleased 25236 24812 2474 77 3 0x100012 0x80 kqread dhcpleased 2474 80316 1 0 3 0 0x80 kqread dhcpleased 56401 8572 0 0 2 0x14000 0x200 smr 99475 58484 0 0 2 0x14000 0x200 zerothread 9137 72598 0 0 3 0x14000 0x200 aiodoned aiodoned 58160 131668 0 0 2 0x14000 0xe00 update 60907 279113 0 0 3 0x14000 0x200 cleaner cleaner 34624 6641 0 0 3 0x14000 0x200 reaper reaper 51466 236619 0 0 3 0x14000 0x200 pgdaemon pagedaemon 64597 83945 0 0 3 0x14000 0x200 bored viomb 53467 110010 0 0 3 0x14000 0x40000200 acpi0 acpi0 33493 183595 0 0 3 0x14000 0x40000200 idle1 71619 50482 0 0 3 0x14000 0x200 bored softnet1 25668 459830 0 0 2 0x14000 0x200 softnet0 41220 447861 0 0 2 0x14000 0x200 systqmp 12989 438081 0 0 3 0x14000 0x200 bored systq 21846 479973 0 0 3 0x14000 0x200 netlock softclockmp 15698 465961 0 0 7 0x14000 0x40000200 softclock 75520 476748 0 0 3 0x14000 0x40000200 idle0 1 390209 0 0 3 0x2 0x80 wait init 0 0 -1 0 3 0x10000 0x200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive mutex /syzkaller/managers/multicore/kernel/sys/kern/kern_malloc.c:96 r = 0 (0xffffffff838f93c8) #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+0x4b4 sys/kern/kern_lock.c:487 #2 malloc+0x2ef sys/kern/kern_malloc.c:200 #3 spec_open_clone+0x333 sys/kern/spec_vnops.c:-1 #4 spec_open+0x319 sys/kern/spec_vnops.c:148 #5 VOP_OPEN+0x8b sys/kern/vfs_vops.c:138 #6 vn_open+0x7a5 sys/kern/vfs_vnops.c:183 #7 doopenat+0x35b sys/kern/vfs_syscalls.c:1163 #8 sys_open+0x59 sys/kern/vfs_syscalls.c:1065 #9 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #9 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 #10 Xsyscall+0x128 Process 90170 (syz-executor) thread 0xffff800038b9c2c0 (405382) exclusive rrwlock inode r = 0 (0xfffffc806edb2920) #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 spec_open_clone+0x290 sys/kern/spec_vnops.c:725 #6 spec_open+0x319 sys/kern/spec_vnops.c:148 #7 VOP_OPEN+0x8b sys/kern/vfs_vops.c:138 #8 vn_open+0x7a5 sys/kern/vfs_vnops.c:183 #9 doopenat+0x35b sys/kern/vfs_syscalls.c:1163 #10 sys_open+0x59 sys/kern/vfs_syscalls.c:1065 #11 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #11 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 #12 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83a28700) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 doopenat+0x340 sys/kern/vfs_syscalls.c:1163 #2 sys_open+0x59 sys/kern/vfs_syscalls.c:1065 #3 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #3 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 #4 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11063 12084K 12159K 166960K 12586 0 pcb 17 16K 32K 166960K 730 0 rtable 223 17K 19K 166960K 2604 0 pf 40 19K 26K 166960K 292 0 ifaddr 39 7K 8K 166960K 334 0 ifgroup 55 2K 2K 166960K 343 0 sysctl 3 1K 9K 166960K 9 0 counters 70 37K 37K 166960K 218 0 ioctlops 0 0K 4K 166960K 1621 0 iov 0 0K 16K 166960K 83 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1415 89K 89K 166960K 2324 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 3 0 VM map 2 1K 1K 166960K 2 0 sem 7 0K 0K 166960K 8 0 dirhash 21 3K 3K 166960K 24 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 12 41K 93K 166960K 1426 0 sigio 0 0K 0K 166960K 39 0 proc 75 131K 180K 166960K 2522 0 subproc 72 4K 4K 166960K 702 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 153 0 in_multi 81 5K 6K 166960K 866 0 ether_multi 1 0K 0K 166960K 3 0 mrt 1 0K 0K 166960K 36 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 67 307K 307K 166960K 67 0 exec 0 0K 1K 166960K 1296 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 197 166K 182K 166960K 11146 0 UVM aobj 6 2K 2K 166960K 6 0 pinsyscall 37 74K 104K 166960K 4380 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 9 0 NDP 18 0K 2K 166960K 242 0 temp 37 9114K 9179K 166960K 38224 0 kqueue 13 20K 24K 166960K 68 0 SYN cache 2 16K 16K 166960K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 28 0 0 1 0 1 1 0 8 0 rtpcb 120 192 0 189 1 0 1 1 0 8 0 rtentry 176 874 0 784 6 1 5 6 0 8 0 unpcb 144 211 0 194 4 0 4 4 0 8 3 syncache 336 7 0 7 3 2 1 1 0 8 1 tcpcb 736 90 0 86 4 3 1 4 0 8 0 arp 136 156 0 142 1 0 1 1 0 8 0 inpcb 328 1653 0 1646 9 0 9 9 0 8 8 nd6 152 232 0 213 1 0 1 1 0 8 0 pkpcb 40 5 0 5 2 2 0 1 0 8 0 kcovpl 48 77 0 70 1 0 1 1 0 8 0 ppxss 1192 4 0 4 2 1 1 1 0 8 1 pfstscr 40 8 0 4 1 0 1 1 0 8 0 pffrag 232 3 0 0 1 0 1 1 0 482 0 pffrnode 88 2 0 0 1 0 1 1 0 8 0 pffrent 40 3 0 0 1 0 1 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfrktable 1344 33 0 28 1 0 1 1 0 8 0 pfanchor 1288 8 0 3 1 0 1 1 0 8 0 pftag 88 5 0 5 1 0 1 1 0 8 1 pfstitem 24 67 0 22 1 0 1 1 0 8 0 pfstkey 128 67 0 22 2 0 2 2 0 8 0 pfstate 448 63 0 20 6 0 6 6 0 8 0 pfrule 1360 29 0 23 2 1 1 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 3521 0 3149 31 6 25 31 0 8 1 art_table 40 3523 0 3149 6 1 5 6 0 8 1 art_node 32 874 0 792 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 1 1 0 1 1 0 8 0 semapl 72 5 0 0 1 0 1 1 0 8 0 shmpl 112 3 0 0 1 0 1 1 0 8 0 dirhash 1024 25 0 2 3 0 3 3 0 8 0 dino2pl 256 2103 0 485 102 0 102 102 0 8 0 ffsino 296 2103 0 485 125 0 125 125 0 8 0 nchpl 144 2612 0 672 72 0 72 72 0 8 0 vnodes 216 3085 0 0 172 0 172 172 0 8 0 namei 1024 20147 0 20147 3 2 1 2 0 8 1 percpumem 16 125 0 74 1 0 1 1 0 8 0 pfiaddrpl 120 7 0 5 1 0 1 1 0 8 0 kstatmem 264 177 0 148 3 0 3 3 0 8 0 scxspl 216 9601 0 9601 12 9 3 8 1 8 3 plimitpl 152 128 0 111 1 0 1 1 0 8 0 sigapl 424 1604 0 1562 7 1 6 7 0 8 0 knotepl 120 466 0 0 15 0 15 15 0 8 0 kqueuepl 224 151 0 142 5 4 1 5 0 8 0 pipepl 344 353 0 326 3 0 3 3 0 8 0 fdescpl 528 1588 0 1562 3 0 3 3 0 8 0 filepl 160 7298 0 7090 16 1 15 15 0 8 5 lockfpl 104 263 0 261 2 1 1 2 0 8 0 lockfspl 48 113 0 111 1 0 1 1 0 8 0 sessionpl 144 102 0 93 1 0 1 1 0 8 0 pgrppl 48 180 0 163 1 0 1 1 0 8 0 ucredpl 104 343 0 330 1 0 1 1 0 8 0 zombiepl 144 1567 0 1562 1 0 1 1 0 8 0 processpl 1232 1604 0 1562 5 1 4 5 0 8 0 procpl 664 2197 0 2155 6 0 6 6 0 8 0 sosppl 176 1 0 1 1 1 0 1 0 8 0 sockpl 752 2217 0 2190 28 15 13 16 0 8 10 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl16k 16384 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl9k128 9344 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 123 0 0 16 0 16 16 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 30 0 0 4 0 4 4 0 8 0 mextrefs 64 29 0 0 1 0 1 1 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 285 0 0 18 0 18 18 0 8 0 bufpl 272 3376 0 106 218 0 218 218 0 8 0 anonpl 32 5162 0 0 42 0 42 42 0 247 0 amapchunkpl 152 29794 0 29434 29 8 21 26 0 158 3 amappl16 200 2170 0 2153 8 3 5 5 0 8 3 amappl15 192 3 0 3 1 1 0 1 0 8 0 amappl14 184 1262 0 1261 1 0 1 1 0 8 0 amappl13 176 264 0 252 1 0 1 1 0 8 0 amappl12 168 2113 0 2087 2 0 2 2 0 8 0 amappl11 160 8 0 8 1 1 0 1 0 8 0 amappl10 152 67 0 53 1 0 1 1 0 8 0 amappl9 144 272 0 272 1 1 0 1 0 8 0 amappl8 136 375 0 372 1 0 1 1 0 8 0 amappl7 128 321 0 308 1 0 1 1 0 8 0 amappl6 120 844 0 843 1 0 1 1 0 8 0 amappl5 112 125 0 112 1 0 1 1 0 8 0 amappl4 104 505 0 486 1 0 1 1 0 8 0 amappl3 96 5671 0 5597 3 0 3 3 0 8 0 amappl2 88 1452 0 1379 2 0 2 2 0 8 0 amappl1 80 20500 0 19918 16 2 14 15 0 8 1 amappl 88 9193 0 9069 5 1 4 5 0 92 0 uvmvnodes 80 110 0 0 3 0 3 3 0 8 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 2 0 1 1 0 1 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 19 0 18 1 0 1 1 0 8 0 aobjpl 72 5 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1588 0 1562 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1588 0 1562 1 0 1 1 0 8 0 vmmpekpl 168 13787 0 13727 4 0 4 4 0 8 0 vmmpepl 168 110505 0 108859 90 5 85 87 0 357 2 vmsppl 488 1587 0 1562 5 0 5 5 0 8 0 rwobjpl 80 32707 0 31714 24 0 24 24 0 8 0 pdppl 4096 3183 0 3124 141 72 69 85 0 8 10 pvpl 32 11264 0 0 91 0 91 91 0 265 0 pmappl 256 1587 0 1562 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 562 0 88 14 0 14 14 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83934ff0) 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 __mp_lock(ffffffff83a27f00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a27f00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x4f sys/dev/kcov.c:159 __mp_acquire_count(ffffffff83a27f00,1) at __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1 sleep_finish(ffffffffffffffff,1) at sleep_finish+0x2d8 sys/kern/kern_synch.c:369 softclock_thread_run(ffffffff839d1f18) at softclock_thread_run+0x79 sys/kern/kern_timeout.c:836 softclock_thread(ffff800045ffef90) at softclock_thread+0x10a sys/kern/kern_timeout.c:858 end trace frame: 0x0, count: 3 ddb{0}> trace x86_ipi_db(ffffffff83934ff0) 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 __mp_lock(ffffffff83a27f00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a27f00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x4f sys/dev/kcov.c:159 __mp_acquire_count(ffffffff83a27f00,1) at __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1 sleep_finish(ffffffffffffffff,1) at sleep_finish+0x2d8 sys/kern/kern_synch.c:369 softclock_thread_run(ffffffff839d1f18) at softclock_thread_run+0x79 sys/kern/kern_timeout.c:836 softclock_thread(ffff800045ffef90) at softclock_thread+0x10a sys/kern/kern_timeout.c:858 end trace frame: 0x0, count: -12 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x688 savectx() at savectx+0xae end of kernel end trace frame: 0x788b05026e40, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x788b05026e40, count: -1