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 *141357 19770 0 0 0x4000000 1 syz-executor.0 129613 84686 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(ffffffff8263fbb8,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8263f9b0) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800021d6d000) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dda054,fffffd8063532f48) at alltraps_kern_meltdown+0x7b frag6_input(ffff800021d6d368,ffff800021d6d374,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800021d6d368,ffff800021d6d374,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800021d6d368,ffff800021d6d374,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800021d6d368,ffff800021d6d374,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806f2dee00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806f2dee00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806bc08000,ffff800000af0f80,fffffd806f6b95e8,0,0,fffffd806f6b9578) at ip6_output+0xd59 rip6_output(fffffd806bc08000,fffffd80658c3328,ffff800021d6d6d8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff800021d6d770, 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(ffffffff8263fbb8,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8263f9b0) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800021d6d000) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dda054,fffffd8063532f48) at alltraps_kern_meltdown+0x7b frag6_input(ffff800021d6d368,ffff800021d6d374,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800021d6d368,ffff800021d6d374,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800021d6d368,ffff800021d6d374,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800021d6d368,ffff800021d6d374,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806f2dee00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806f2dee00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806bc08000,ffff800000af0f80,fffffd806f6b95e8,0,0,fffffd806f6b9578) at ip6_output+0xd59 rip6_output(fffffd806bc08000,fffffd80658c3328,ffff800021d6d6d8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd80658c3328,9,fffffd806bc08000,0,0,ffff800020ab0780) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd80658c3328,0,ffff800021d6d908,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ab0780,3,ffff800021d6d908,0,ffff800021d6da10) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020ab0780,ffff800021d6d9a8,ffff800021d6da10) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800021d6da80) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800021d6da80) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,e58b6ca4010) at Xsyscall+0x128 end of kernel end trace frame: 0xe5b91ee3400, count: -20 ddb{1}> show registers rdi 0xffffffff81b1dce7 db_enter+0x17 rsi 0x2feb __ALIGN_SIZE+0x1feb rbp 0xffff800021d6cd60 rbx 0xffff800021d6ce10 rdx 0x2fec __ALIGN_SIZE+0x1fec rcx 0xffff800021db0000 rax 0xffff800021db0000 r8 0xffffffff81b8cec3 kprintf+0x173 r9 0x1 r10 0x25 r11 0xf15493612736146c r12 0x3000000008 r13 0xffff800021d6cd70 r14 0x100 r15 0x1 rip 0xffffffff81b1dce8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021d6cd50 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=141357 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020ab0018,0xffffffff82623150 process=0xffff800020add500 user=0xffff800021d68000, vmspace=0xfffffd807f00c450 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 19770 329980 22459 0 2 0 syz-executor.0 *19770 141357 22459 0 7 0x4000000 syz-executor.0 22459 45146 6518 0 3 0x82 nanosleep syz-executor.0 78379 42935 6518 0 2 0x482 syz-executor.1 1367 207730 1 0 3 0x100083 ttyin getty 90260 68448 0 0 3 0x14200 bored sosplice 6518 510400 26035 0 3 0x82 thrsleep syz-fuzzer 6518 468156 26035 0 3 0x4000082 nanosleep syz-fuzzer 6518 171348 26035 0 3 0x4000082 thrsleep syz-fuzzer 6518 11028 26035 0 3 0x4000082 thrsleep syz-fuzzer 6518 417091 26035 0 3 0x4000082 thrsleep syz-fuzzer 6518 62300 26035 0 3 0x4000082 thrsleep syz-fuzzer 6518 455979 26035 0 3 0x4000082 nanosleep syz-fuzzer 6518 248627 26035 0 3 0x4000082 thrsleep syz-fuzzer 6518 272761 26035 0 3 0x4000082 thrsleep syz-fuzzer 6518 17720 26035 0 3 0x4000082 kqread syz-fuzzer 26035 496725 6002 0 3 0x10008a pause ksh 6002 52554 83742 0 3 0x92 select sshd 83742 227793 1 0 3 0x80 select sshd 5386 253837 67278 74 3 0x100092 bpf pflogd 67278 237013 1 0 3 0x80 netio pflogd 57250 155815 72151 73 3 0x100090 kqread syslogd 72151 392837 1 0 3 0x100082 netio syslogd 508 483275 1 77 3 0x100090 poll dhclient 9843 101958 1 0 3 0x80 poll dhclient 21905 90285 0 0 3 0x14200 pgzero zerothread 53161 41105 0 0 3 0x14200 aiodoned aiodoned 38493 96821 0 0 3 0x14200 syncer update 70361 155282 0 0 3 0x14200 cleaner cleaner 85316 511610 0 0 3 0x14200 reaper reaper 93756 462790 0 0 3 0x14200 pgdaemon pagedaemon 62436 205912 0 0 3 0x14200 bored crynlk 14211 239743 0 0 3 0x14200 bored crypto 94501 306129 0 0 3 0x40014200 acpi0 acpi0 4990 87670 0 0 3 0x40014200 idle1 59207 352111 0 0 3 0x14200 bored softnet 17896 95532 0 0 3 0x14200 bored systqmp 30438 323369 0 0 3 0x14200 bored systq 84686 129613 0 0 7 0x40014200 softclock 9563 278179 0 0 3 0x40014200 idle0 75394 129821 0 0 3 0x14200 bored smr 1 94136 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 (0xffffffff82510f30) #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 19770 (syz-executor.0) thread 0xffff800020ab0780 (141357) exclusive rwlock netlock r = 0 (0xffffffff8248ae98) #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 (0xffffffff82510f30) #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 9637 6605K 15113K 78643K 46025 0 0 pcb 14 8K 8K 78643K 1506 0 0 rtable 115 12K 13K 78643K 4391 0 0 ifaddr 92 24K 27K 78643K 1589 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 2161 0 0 iov 0 0K 32K 78643K 1413 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1195 75K 77K 78643K 13893 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 185 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 1782 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 14085 0 0 sigio 0 0K 0K 78643K 183 0 0 proc 55 51K 71K 78643K 3585 0 0 subproc 32 2K 2K 78643K 766 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 1097 0 0 in_multi 33 2K 2K 78643K 883 0 0 ether_multi 1 0K 0K 78643K 65 0 0 mrt 0 0K 0K 78643K 54 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 120 530K 530K 78643K 120 0 0 exec 0 0K 1K 78643K 1903 0 0 pfkey data 0 0K 4K 78643K 2 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 128 23K 39K 78643K 45927 0 0 UVM aobj 130 5K 5K 78643K 143 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 1578 0 0 NDP 23 0K 1K 78643K 484 0 0 temp 249 3557K 4197K 78643K 180684 0 0 kqueue 0 0K 0K 78643K 124 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 96 0 90 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 643 0 641 1 0 1 1 0 8 0 rtentry 112 528 0 484 4 2 2 2 0 8 0 unpcb 120 4426 0 4415 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 10275 0 10275 1 1 0 1 0 8 0 tcpcb 544 2616 0 2611 1 0 1 1 0 8 0 inpcb 280 7840 0 7832 20 19 1 2 0 8 0 rttmr 72 11 0 11 11 11 0 1 0 8 0 ip6q 72 2 0 1 2 1 1 1 0 8 0 ip6af 48 3 0 2 2 1 1 1 0 8 0 nd6 48 132 0 126 1 0 1 1 0 8 0 pkpcb 40 70 0 70 22 22 0 1 0 8 0 swfcl 56 3 0 0 1 0 1 1 0 8 0 ppxss 1128 275 0 275 27 26 1 1 0 8 1 pffrag 232 30 0 30 13 13 0 1 0 482 0 pffrnode 88 30 0 30 13 13 0 1 0 8 0 pffrent 40 76 0 76 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 24 379 0 362 1 0 1 1 0 8 0 pfstkey 112 381 0 364 3 2 1 2 0 8 0 pfstate 328 381 0 364 9 6 3 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 2206 0 2009 25 12 13 14 0 8 0 art_table 32 2207 0 2009 2 0 2 2 0 8 0 art_node 16 523 0 483 1 0 1 1 0 8 0 sysvmsgpl 40 14 0 12 1 0 1 1 0 8 0 semapl 112 1780 0 1770 1 0 1 1 0 8 0 shmpl 112 141 0 13 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 22900 0 21446 48 0 48 48 0 8 1 ffsino 272 22900 0 21446 98 0 98 98 0 8 0 nchpl 144 42642 0 41006 62 0 62 62 0 8 0 uvmvnodes 72 7308 0 0 133 0 133 133 0 8 0 vnodes 200 7308 0 0 385 0 385 385 0 8 0 namei 1024 140338 0 140338 6 5 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 34 0 34 19 19 0 1 0 8 0 scxspl 192 122267 0 122267 56 53 3 7 0 8 3 plimitpl 152 1289 0 1281 1 0 1 1 0 8 0 sigapl 432 14162 0 14147 3 1 2 3 0 8 0 futexpl 56 181444 0 181444 4 3 1 1 0 8 1 knotepl 112 3108 0 3089 1 0 1 1 0 8 0 kqueuepl 104 2776 0 2774 1 0 1 1 0 8 0 pipepl 112 7998 0 7977 18 17 1 2 0 8 0 fdescpl 488 14163 0 14147 3 0 3 3 0 8 0 filepl 152 83472 0 83370 22 17 5 7 0 8 1 lockfpl 104 4560 0 4560 5 4 1 1 0 8 1 lockfspl 48 1526 0 1526 5 4 1 1 0 8 1 sessionpl 112 63 0 52 1 0 1 1 0 8 0 pgrppl 48 206 0 195 1 0 1 1 0 8 0 ucredpl 96 15110 0 15100 1 0 1 1 0 8 0 zombiepl 144 14154 0 14153 5 4 1 1 0 8 0 processpl 896 14186 0 14153 4 0 4 4 0 8 0 procpl 632 42980 0 42937 21 16 5 5 0 8 1 srpgc 64 95 0 95 36 35 1 1 0 8 1 sosppl 128 172 0 172 35 35 0 1 0 8 0 sockpl 384 13119 0 13098 20 17 3 5 0 8 0 mcl64k 65536 747 0 0 84 79 5 66 0 8 0 mcl16k 16384 30 0 0 4 2 2 3 0 8 0 mcl12k 12288 33 0 0 2 0 2 2 0 8 0 mcl9k 9216 31 0 0 3 1 2 2 0 8 0 mcl8k 8192 33 0 0 5 2 3 3 0 8 0 mcl4k 4096 21 0 0 3 0 3 3 0 8 0 mcl2k2 2112 12 0 0 1 0 1 1 0 8 0 mcl2k 2048 188 0 0 20 5 15 20 0 8 0 mtagpl 80 84 0 0 1 0 1 1 0 8 0 mbufpl 256 1070 0 0 38 3 35 38 0 8 1 bufpl 256 36372 0 28791 474 0 474 474 0 8 0 anonpl 16 1247768 0 1237282 290 228 62 70 0 124 2 amapchunkpl 152 83899 0 83793 87 81 6 18 0 158 0 amappl16 192 69277 0 68550 313 273 40 49 0 8 2 amappl15 184 1814 0 1814 7 6 1 1 0 8 1 amappl14 176 836 0 828 1 0 1 1 0 8 0 amappl13 168 1678 0 1678 7 7 0 1 0 8 0 amappl12 160 1371 0 1366 1 0 1 1 0 8 0 amappl11 152 2703 0 2688 1 0 1 1 0 8 0 amappl10 144 2455 0 2448 1 0 1 1 0 8 0 amappl9 136 4685 0 4681 1 0 1 1 0 8 0 amappl8 128 4182 0 4138 2 0 2 2 0 8 0 amappl7 120 2482 0 2474 1 0 1 1 0 8 0 amappl6 112 2575 0 2565 1 0 1 1 0 8 0 amappl5 104 1852 0 1837 1 0 1 1 0 8 0 amappl4 96 13991 0 13957 2 1 1 2 0 8 0 amappl3 88 1771 0 1761 1 0 1 1 0 8 0 amappl2 80 112393 0 112320 4 1 3 3 0 8 0 amappl1 72 310231 0 309791 27 17 10 20 0 8 0 amappl 80 43947 0 43910 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 64 142 0 13 3 0 3 3 0 8 0 uaddrrnd 24 14163 0 14147 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 14163 0 14147 1 0 1 1 0 8 0 vmmpekpl 168 111146 0 111116 2 0 2 2 0 8 0 vmmpepl 168 1719713 0 1717827 544 434 110 110 0 357 17 vmsppl 368 14162 0 14147 2 0 2 2 0 8 0 pdppl 4096 28333 0 28294 7 1 6 6 0 8 0 pvpl 32 3329225 0 3315515 636 476 160 171 0 265 19 pmappl 232 14162 0 14147 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 775 0 112 20 0 20 20 0 8 0