panic: acquiring blockable sleep lock with spinlock or critical section held (kernel_lock) &kernel_lock Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *421777 92454 0 0 0x4000000 1 syz-executor.1 11121 50290 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 witness_checkorder(ffffffff8262c5a8,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8262c3a0) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800021b7b020) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dfa054,fffffd8062b91eb8) at alltraps_kern_meltdown+0x7b frag6_input(ffff800021b7b388,ffff800021b7b394,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800021b7b388,ffff800021b7b394,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800021b7b388,ffff800021b7b394,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800021b7b388,ffff800021b7b394,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd807f02c000) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd807f02c000,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd8069527a00,ffff800000afb580,fffffd806f6c04d0,0,0,fffffd806f6c0460) at ip6_output+0xd59 rip6_output(fffffd8069527a00,fffffd806f6c1d80,ffff800021b7b6f8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff800021b7b790, count: 0 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 acquiring blockable sleep lock with spinlock or critical section held (kernel_lock) &kernel_lock ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 witness_checkorder(ffffffff8262c5a8,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8262c3a0) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800021b7b020) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dfa054,fffffd8062b91eb8) at alltraps_kern_meltdown+0x7b frag6_input(ffff800021b7b388,ffff800021b7b394,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800021b7b388,ffff800021b7b394,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800021b7b388,ffff800021b7b394,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800021b7b388,ffff800021b7b394,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd807f02c000) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd807f02c000,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd8069527a00,ffff800000afb580,fffffd806f6c04d0,0,0,fffffd806f6c0460) at ip6_output+0xd59 rip6_output(fffffd8069527a00,fffffd806f6c1d80,ffff800021b7b6f8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd806f6c1d80,9,fffffd8069527a00,0,0,ffff800020ab1160) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd806f6c1d80,0,ffff800021b7b928,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ab1160,4,ffff800021b7b928,0,ffff800021b7ba30) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020ab1160,ffff800021b7b9c8,ffff800021b7ba30) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800021b7baa0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800021b7baa0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,6eee9cab010) at Xsyscall+0x128 end of kernel end trace frame: 0x6f1386fc250, count: -20 ddb{1}> show registers rdi 0xffffffff81ae7517 db_enter+0x17 rsi 0x363c __ALIGN_SIZE+0x263c rbp 0xffff800021b7ad80 rbx 0xffff800021b7ae30 rdx 0x363d __ALIGN_SIZE+0x263d rcx 0xffff80002116e000 rax 0xffff80002116e000 r8 0xffffffff81048ff3 kprintf+0x173 r9 0x1 r10 0x25 r11 0x22cc9767b4c9207 r12 0x3000000008 r13 0xffff800021b7ad90 r14 0x100 r15 0x1 rip 0xffffffff81ae7518 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021b7ad70 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=421777 stat=onproc flags process=0 proc=4000000 pri=81, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff800020ab18c8,0xffff800020ab0518 process=0xffff800020add880 user=0xffff800021b76000, vmspace=0xfffffd807f00c730 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 97043 11726 33072 0 2 0 syz-executor.0 92454 371271 98678 0 2 0 syz-executor.1 *92454 421777 98678 0 7 0x4000000 syz-executor.1 33072 371652 92652 0 3 0x82 nanosleep syz-executor.0 98678 367292 92652 0 3 0x82 nanosleep syz-executor.1 35648 389830 0 0 3 0x14200 bored sosplice 92652 325300 37322 0 3 0x82 thrsleep syz-fuzzer 92652 193369 37322 0 2 0x4000482 syz-fuzzer 92652 246755 37322 0 3 0x4000082 thrsleep syz-fuzzer 92652 355556 37322 0 3 0x4000082 thrsleep syz-fuzzer 92652 323097 37322 0 3 0x4000082 kqread syz-fuzzer 92652 400366 37322 0 3 0x4000082 thrsleep syz-fuzzer 92652 247390 37322 0 3 0x4000082 thrsleep syz-fuzzer 92652 269567 37322 0 2 0x4000482 syz-fuzzer 92652 417214 37322 0 3 0x4000082 thrsleep syz-fuzzer 92652 341425 37322 0 3 0x4000082 thrsleep syz-fuzzer 37322 412622 81401 0 3 0x10008a pause ksh 81401 285708 84460 0 3 0x92 select sshd 75815 392325 1 0 3 0x100083 ttyin getty 84460 479266 1 0 3 0x80 select sshd 81750 238483 71293 74 3 0x100092 bpf pflogd 71293 391610 1 0 3 0x80 netio pflogd 45329 104875 96619 73 3 0x100090 kqread syslogd 96619 30482 1 0 3 0x100082 netio syslogd 224 410951 0 0 2 0x14200 zerothread 34228 444082 0 0 3 0x14200 aiodoned aiodoned 42349 46094 0 0 3 0x14200 syncer update 40075 336723 0 0 3 0x14200 cleaner cleaner 94479 125324 0 0 3 0x14200 reaper reaper 55903 233143 0 0 3 0x14200 pgdaemon pagedaemon 10516 231388 0 0 3 0x14200 bored crynlk 70980 82764 0 0 3 0x14200 bored crypto 36815 48420 0 0 3 0x40014200 acpi0 acpi0 61906 118200 0 0 3 0x40014200 idle1 21632 62416 0 0 3 0x14200 bored softnet 49494 449913 0 0 3 0x14200 bored systqmp 13279 487598 0 0 3 0x14200 bored systq 50290 11121 0 0 7 0x40014200 softclock 25886 131384 0 0 3 0x40014200 idle0 30820 48703 0 0 3 0x14200 bored smr 1 93980 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive mutex /syzkaller/managers/multicore/kernel/sys/netinet6/frag6.c:57 r = 0 (0xffffffff824f84e0) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 mtx_enter_try+0x102 #2 mtx_enter+0x4b sys/kern/kern_lock.c:266 #3 frag6_input+0x237 sys/netinet6/frag6.c:183 #4 ip_deliver+0x353 sys/netinet/ip_input.c:665 #5 ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] #5 ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 #6 ipv6_input+0x48 sys/netinet6/ip6_input.c:171 #7 if_input_local+0x121 sys/net/if.c:783 #8 ip6_output+0xd59 #9 rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 #10 rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 #11 sosend+0x668 sys/kern/uipc_socket.c:524 #12 dofilewritev+0x1ac sys/kern/sys_generic.c:364 #13 sys_write+0x83 sys/kern/sys_generic.c:284 #14 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #14 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #15 Xsyscall+0x128 Process 92454 (syz-executor.1) thread 0xffff800020ab1160 (421777) exclusive rwlock netlock r = 0 (0xffffffff8250b088) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x52c sys/kern/uipc_socket.c:512 #3 dofilewritev+0x1ac sys/kern/sys_generic.c:364 #4 sys_write+0x83 sys/kern/sys_generic.c:284 #5 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #5 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #6 Xsyscall+0x128 exclusive mutex /syzkaller/managers/multicore/kernel/sys/netinet6/frag6.c:57 r = 0 (0xffffffff824f84e0) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 mtx_enter_try+0x102 #2 mtx_enter+0x4b sys/kern/kern_lock.c:266 #3 frag6_input+0x237 sys/netinet6/frag6.c:183 #4 ip_deliver+0x353 sys/netinet/ip_input.c:665 #5 ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] #5 ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 #6 ipv6_input+0x48 sys/netinet6/ip6_input.c:171 #7 if_input_local+0x121 sys/net/if.c:783 #8 ip6_output+0xd59 #9 rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 #10 rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 #11 sosend+0x668 sys/kern/uipc_socket.c:524 #12 dofilewritev+0x1ac sys/kern/sys_generic.c:364 #13 sys_write+0x83 sys/kern/sys_generic.c:284 #14 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #14 syscall+0x552 sys/arch/amd64/amd64/trap.c:555 #15 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9632 6406K 10890K 78643K 36099 0 0 pcb 14 8K 8K 78643K 1218 0 0 rtable 117 12K 13K 78643K 3524 0 0 ifaddr 96 24K 27K 78643K 1309 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 2017 0 0 iov 0 0K 32K 78643K 898 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1196 75K 77K 78643K 10390 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 132 0 0 VM map 2 1K 1K 78643K 16 0 0 sem 12 0K 0K 78643K 1126 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 10577 0 0 sigio 1 0K 0K 78643K 130 0 0 proc 55 51K 83K 78643K 2627 0 0 subproc 32 2K 2K 78643K 605 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 1029 0 0 in_multi 33 2K 2K 78643K 777 0 0 ether_multi 1 0K 0K 78643K 57 0 0 mrt 0 0K 0K 78643K 45 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 126 556K 556K 78643K 126 0 0 exec 0 0K 1K 78643K 1436 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 114 22K 31K 78643K 34686 0 0 UVM aobj 130 5K 5K 78643K 148 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 2 0K 1K 78643K 1208 0 0 NDP 24 0K 1K 78643K 400 0 0 temp 256 3557K 4196K 78643K 133320 0 0 kqueue 0 0K 0K 78643K 73 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 77 0 71 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 431 0 431 2 1 1 1 0 8 1 rtentry 112 436 0 392 3 1 2 2 0 8 0 unpcb 120 3469 0 3461 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 8680 0 8680 3 3 0 2 0 8 0 tcpcb 544 2090 0 2085 1 0 1 1 0 8 0 inpcb 280 6041 0 6031 22 21 1 2 0 8 0 rttmr 72 8 0 8 6 6 0 1 0 8 0 ip6q 72 2 0 1 2 1 1 1 0 8 0 ip6af 48 1 0 0 1 0 1 1 0 8 0 nd6 48 105 0 99 1 0 1 1 0 8 0 pkpcb 40 56 0 56 21 20 1 1 0 8 1 swfcl 56 5 0 0 1 0 1 1 0 8 0 ppxss 1128 225 0 225 17 16 1 1 0 8 1 pffrag 232 20 0 20 12 12 0 1 0 482 0 pffrnode 88 20 0 20 12 12 0 1 0 8 0 pffrent 40 52 0 52 13 13 0 1 0 8 0 pfosfp 40 846 0 846 5 5 0 5 0 8 0 pfosfpen 112 1428 0 1428 21 21 0 21 0 8 0 pfstitem 24 288 0 266 1 0 1 1 0 8 0 pfstkey 112 288 0 266 2 1 1 2 0 8 0 pfstate 328 288 0 266 5 1 4 4 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1782 0 1585 20 7 13 14 0 8 0 art_table 32 1783 0 1585 2 0 2 2 0 8 0 art_node 16 420 0 380 1 0 1 1 0 8 0 sysvmsgpl 40 48 0 39 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 1122 0 1112 1 0 1 1 0 8 0 shmpl 112 146 0 18 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 17683 0 16250 47 0 47 47 0 8 0 ffsino 272 17683 0 16250 97 0 97 97 0 8 0 nchpl 144 32456 0 30826 62 0 62 62 0 8 0 uvmvnodes 72 6391 0 0 117 0 117 117 0 8 0 vnodes 200 6391 0 0 337 0 337 337 0 8 0 namei 1024 105389 0 105389 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 552 14 0 14 6 6 0 1 0 8 0 scsiplug 64 22 0 22 13 13 0 1 0 8 0 scxspl 192 94469 0 94469 39 38 1 7 0 8 1 plimitpl 152 1034 0 1027 1 0 1 1 0 8 0 sigapl 432 10678 0 10664 3 1 2 3 0 8 0 futexpl 56 135679 0 135679 1 0 1 1 0 8 1 knotepl 112 2275 0 2256 1 0 1 1 0 8 0 kqueuepl 104 2221 0 2219 1 0 1 1 0 8 0 pipepl 112 5804 0 5785 11 10 1 2 0 8 0 fdescpl 488 10679 0 10664 3 0 3 3 0 8 0 filepl 152 62953 0 62862 20 15 5 7 0 8 1 lockfpl 104 3057 0 3057 2 1 1 1 0 8 1 lockfspl 48 1072 0 1072 2 1 1 1 0 8 1 sessionpl 112 51 0 42 1 0 1 1 0 8 0 pgrppl 48 130 0 121 1 0 1 1 0 8 0 ucredpl 96 11625 0 11617 1 0 1 1 0 8 0 zombiepl 144 10664 0 10664 2 1 1 1 0 8 1 processpl 896 10695 0 10664 4 0 4 4 0 8 0 procpl 632 32231 0 32190 21 17 4 5 0 8 0 srpgc 64 74 0 74 30 30 0 1 0 8 0 sosppl 128 93 0 93 22 22 0 1 0 8 0 sockpl 384 10117 0 10103 16 13 3 4 0 8 1 mcl64k 65536 21 0 0 3 0 3 3 0 8 0 mcl16k 16384 17 0 0 3 1 2 3 0 8 0 mcl12k 12288 33 0 0 2 0 2 2 0 8 0 mcl9k 9216 41 0 0 2 0 2 2 0 8 0 mcl8k 8192 25 0 0 4 1 3 3 0 8 0 mcl4k 4096 25 0 0 3 0 3 3 0 8 0 mcl2k2 2112 10 0 0 1 0 1 1 0 8 0 mcl2k 2048 280 0 0 32 8 24 32 0 8 0 mtagpl 80 70 0 0 1 0 1 1 0 8 0 mbufpl 256 543 0 0 17 4 13 17 0 8 0 bufpl 256 28163 0 21144 439 0 439 439 0 8 0 anonpl 16 967231 0 954491 252 184 68 70 0 124 10 amapchunkpl 152 63957 0 63855 97 87 10 18 0 158 3 amappl16 192 52605 0 51878 254 209 45 49 0 8 8 amappl15 184 1521 0 1521 8 8 0 1 0 8 0 amappl14 176 792 0 783 1 0 1 1 0 8 0 amappl13 168 2267 0 2267 5 5 0 1 0 8 0 amappl12 160 1643 0 1639 1 0 1 1 0 8 0 amappl11 152 1416 0 1408 1 0 1 1 0 8 0 amappl10 144 1609 0 1603 1 0 1 1 0 8 0 amappl9 136 1526 0 1523 1 0 1 1 0 8 0 amappl8 128 956 0 916 3 1 2 2 0 8 0 amappl7 120 1658 0 1649 1 0 1 1 0 8 0 amappl6 112 1322 0 1310 1 0 1 1 0 8 0 amappl5 104 2046 0 2031 1 0 1 1 0 8 0 amappl4 96 9979 0 9950 2 1 1 2 0 8 0 amappl3 88 2856 0 2845 1 0 1 1 0 8 0 amappl2 80 84052 0 83987 3 1 2 3 0 8 0 amappl1 72 239864 0 239451 25 15 10 20 0 8 0 amappl 80 33045 0 33011 1 0 1 1 0 84 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 64 147 0 18 3 0 3 3 0 8 0 uaddrrnd 24 10693 0 10664 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 10693 0 10664 1 0 1 1 0 8 0 vmmpekpl 168 84513 0 84482 2 0 2 2 0 8 0 vmmpepl 168 1297167 0 1295290 423 331 92 110 0 357 3 vmsppl 368 10678 0 10664 2 0 2 2 0 8 0 pdppl 4096 21393 0 21356 7 2 5 6 0 8 0 pvpl 32 2578856 0 2562954 514 348 166 172 0 265 32 pmappl 232 10692 0 10678 4 3 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 638 0 27 18 0 18 18 0 8 0