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 *244478 19105 0 0 0x4000000 1 syz-executor.0 81806 6387 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(ffff8000229ab440) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007db9854,fffffd807171df48) at alltraps_kern_meltdown+0x7b frag6_input(ffff8000229ab7a8,ffff8000229ab7b4,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff8000229ab7a8,ffff8000229ab7b4,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff8000229ab7a8,ffff8000229ab7b4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff8000229ab7a8,ffff8000229ab7b4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd807f02c100) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd807f02c100,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806f73b600,ffff800000a98b00,fffffd806f6bfc78,0,0,fffffd806f6bfc08) at ip6_output+0xd59 rip6_output(fffffd806f73b600,fffffd806f6c0180,ffff8000229abb18,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff8000229abbb0, 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(ffff8000229ab440) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007db9854,fffffd807171df48) at alltraps_kern_meltdown+0x7b frag6_input(ffff8000229ab7a8,ffff8000229ab7b4,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff8000229ab7a8,ffff8000229ab7b4,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff8000229ab7a8,ffff8000229ab7b4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff8000229ab7a8,ffff8000229ab7b4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd807f02c100) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd807f02c100,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806f73b600,ffff800000a98b00,fffffd806f6bfc78,0,0,fffffd806f6bfc08) at ip6_output+0xd59 rip6_output(fffffd806f73b600,fffffd806f6c0180,ffff8000229abb18,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd806f6c0180,9,fffffd806f73b600,0,0,ffff800020ab1160) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd806f6c0180,0,ffff8000229abd48,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ab1160,3,ffff8000229abd48,0,ffff8000229abe50) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020ab1160,ffff8000229abde8,ffff8000229abe50) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff8000229abec0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff8000229abec0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,59cfc94b010) at Xsyscall+0x128 end of kernel end trace frame: 0x59f91a8d7e0, count: -20 ddb{1}> show registers rdi 0xffffffff81ae7517 db_enter+0x17 rsi 0x337a __ALIGN_SIZE+0x237a rbp 0xffff8000229ab1a0 rbx 0xffff8000229ab250 rdx 0x337b __ALIGN_SIZE+0x237b rcx 0xffff800021374000 rax 0xffff800021374000 r8 0xffffffff81048ff3 kprintf+0x173 r9 0x1 r10 0x25 r11 0xa7a589ee2bdeaa08 r12 0x3000000008 r13 0xffff8000229ab1b0 r14 0x100 r15 0x1 rip 0xffffffff81ae7518 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000229ab190 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=244478 stat=onproc flags process=0 proc=4000000 pri=80, usrpri=80, nice=20 forw=0xffffffffffffffff, list=0xffff800020ab0290,0xffff800020ab18d8 process=0xffff800020adca80 user=0xffff8000229a6000, vmspace=0xfffffd807f00cb80 estcpu=30, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 62161 102959 67028 0 2 0 syz-executor.1 62161 396943 67028 0 2 0x4000080 syz-executor.1 19105 518938 73823 0 2 0 syz-executor.0 *19105 244478 73823 0 7 0x4000000 syz-executor.0 73823 91237 53005 0 3 0x82 nanosleep syz-executor.0 68891 173500 1 0 3 0x100083 ttyin getty 67028 337385 53005 0 3 0x82 nanosleep syz-executor.1 36293 366224 0 0 3 0x14200 bored sosplice 25645 241883 0 0 3 0x14200 acct acct 53005 280104 52768 0 3 0x82 thrsleep syz-fuzzer 53005 216120 52768 0 3 0x4000082 thrsleep syz-fuzzer 53005 47096 52768 0 3 0x4000082 thrsleep syz-fuzzer 53005 55347 52768 0 3 0x4000082 thrsleep syz-fuzzer 53005 331825 52768 0 3 0x4000082 thrsleep syz-fuzzer 53005 298473 52768 0 3 0x4000082 thrsleep syz-fuzzer 53005 10468 52768 0 3 0x4000082 kqread syz-fuzzer 53005 42810 52768 0 3 0x4000082 thrsleep syz-fuzzer 53005 137697 52768 0 3 0x4000082 thrsleep syz-fuzzer 53005 18385 52768 0 3 0x4000082 thrsleep syz-fuzzer 52768 324921 52416 0 3 0x10008a pause ksh 52416 251493 22786 0 3 0x92 select sshd 22786 322105 1 0 3 0x80 select sshd 17888 81026 93825 74 3 0x100092 bpf pflogd 93825 70271 1 0 3 0x80 netio pflogd 38259 336183 65252 73 3 0x100090 kqread syslogd 65252 118369 1 0 3 0x100082 netio syslogd 91419 354264 1 77 3 0x100090 poll dhclient 63297 205906 1 0 3 0x80 poll dhclient 8369 101326 0 0 2 0x14200 zerothread 32832 380053 0 0 3 0x14200 aiodoned aiodoned 43651 59883 0 0 3 0x14200 syncer update 68507 184009 0 0 3 0x14200 cleaner cleaner 1166 344184 0 0 3 0x14200 reaper reaper 95613 449858 0 0 3 0x14200 pgdaemon pagedaemon 59906 164485 0 0 3 0x14200 bored crynlk 19981 405704 0 0 3 0x14200 bored crypto 9251 240507 0 0 3 0x40014200 acpi0 acpi0 15603 206609 0 0 3 0x40014200 idle1 15947 38680 0 0 3 0x14200 bored softnet 14814 83613 0 0 3 0x14200 bored systqmp 18075 233648 0 0 3 0x14200 bored systq 6387 81806 0 0 7 0x40014200 softclock 6240 138170 0 0 3 0x40014200 idle0 81634 70869 0 0 3 0x14200 bored smr 1 254644 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 19105 (syz-executor.0) thread 0xffff800020ab1160 (244478) 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 9575 6448K 7435K 78643K 20875 0 0 pcb 14 8K 8K 78643K 529 0 0 rtable 112 12K 12K 78643K 1725 0 0 ifaddr 78 18K 20K 78643K 587 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1677 0 0 iov 0 0K 32K 78643K 397 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1207 76K 77K 78643K 5032 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 26 0 0 VM map 2 1K 1K 78643K 26 0 0 sem 12 0K 1K 78643K 460 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 5796 0 0 sigio 0 0K 0K 78643K 134 0 0 proc 55 51K 83K 78643K 1280 0 0 subproc 32 2K 2K 78643K 255 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 452 0 0 in_multi 33 2K 2K 78643K 441 0 0 ether_multi 1 0K 0K 78643K 45 0 0 mrt 0 0K 0K 78643K 30 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 84 371K 371K 78643K 84 0 0 exec 0 0K 1K 78643K 646 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 15236 0 0 UVM aobj 52 3K 3K 78643K 58 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 527 0 0 NDP 18 0K 0K 78643K 197 0 0 temp 215 3556K 3636K 78643K 62794 0 0 kqueue 0 0K 0K 78643K 30 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 30 0 24 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 155 0 153 1 0 1 1 0 8 0 rtentry 112 185 0 141 2 0 2 2 0 8 0 unpcb 120 1522 0 1512 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 200 0 200 12 12 0 1 0 8 0 tcpcb 544 843 0 838 1 0 1 1 0 8 0 inpcb 280 2445 0 2437 2 1 1 2 0 8 0 rttmr 72 6 0 6 3 3 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 42 0 36 1 0 1 1 0 8 0 pkpcb 40 12 0 12 3 2 1 1 0 8 1 swfcl 56 17 0 0 1 0 1 1 0 8 0 ppxss 1128 100 0 99 2 1 1 1 0 8 0 pffrag 232 2 0 2 1 1 0 1 0 482 0 pffrnode 88 2 0 2 1 1 0 1 0 8 0 pffrent 40 4 0 4 1 1 0 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 106 0 61 1 0 1 1 0 8 0 pfstkey 112 112 0 67 2 0 2 2 0 8 0 pfstate 328 112 0 67 6 1 5 5 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 256 763 0 568 17 4 13 14 0 8 0 art_table 32 764 0 568 2 0 2 2 0 8 0 art_node 16 182 0 142 1 0 1 1 0 8 0 sysvmsgpl 40 20 0 19 1 0 1 1 0 8 0 semapl 112 458 0 448 1 0 1 1 0 8 0 shmpl 112 56 0 6 3 1 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 10335 0 8895 47 0 47 47 0 8 0 ffsino 272 10335 0 8895 97 0 97 97 0 8 0 nchpl 144 17224 0 15596 61 0 61 61 0 8 0 uvmvnodes 72 5982 0 0 109 0 109 109 0 8 0 vnodes 200 5982 0 0 315 0 315 315 0 8 0 namei 1024 48027 0 48027 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 552 24 0 24 5 5 0 1 0 8 0 scsiplug 64 13 0 13 3 3 0 1 0 8 0 scxspl 192 51095 0 51095 20 19 1 7 0 8 1 plimitpl 152 428 0 420 1 0 1 1 0 8 0 sigapl 432 5959 0 5943 3 1 2 3 0 8 0 futexpl 56 46554 0 46554 1 0 1 1 0 8 1 knotepl 112 1212 0 1193 1 0 1 1 0 8 0 kqueuepl 104 884 0 882 1 0 1 1 0 8 0 pipepl 112 1242 0 1222 4 3 1 2 0 8 0 fdescpl 488 5960 0 5943 3 0 3 3 0 8 0 filepl 152 23399 0 23298 10 5 5 7 0 8 1 lockfpl 104 1256 0 1256 9 8 1 1 0 8 1 lockfspl 48 443 0 443 9 8 1 1 0 8 1 sessionpl 112 32 0 21 1 0 1 1 0 8 0 pgrppl 48 36 0 25 1 0 1 1 0 8 0 ucredpl 96 5306 0 5297 1 0 1 1 0 8 0 zombiepl 144 5943 0 5943 1 0 1 1 0 8 1 processpl 896 5977 0 5943 4 0 4 4 0 8 0 procpl 632 13808 0 13763 8 3 5 5 0 8 1 srpgc 64 30 0 30 13 13 0 1 0 8 0 sosppl 128 40 0 40 7 6 1 1 0 8 1 sockpl 384 4141 0 4121 6 3 3 4 0 8 1 mcl64k 65536 18 0 0 3 0 3 3 0 8 0 mcl16k 16384 7 0 0 1 0 1 1 0 8 0 mcl12k 12288 26 0 0 2 0 2 2 0 8 0 mcl9k 9216 10 0 0 1 0 1 1 0 8 0 mcl8k 8192 21 0 0 3 1 2 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 11 0 0 1 0 1 1 0 8 0 mcl2k 2048 178 0 0 14 1 13 14 0 8 0 mtagpl 80 52 0 0 1 0 1 1 0 8 0 mbufpl 256 334 0 0 12 0 12 12 0 8 0 bufpl 256 20365 0 13346 439 0 439 439 0 8 0 anonpl 16 434749 0 429876 73 45 28 36 0 124 6 amapchunkpl 152 24917 0 24822 18 9 9 9 0 158 4 amappl16 192 27252 0 27039 60 47 13 22 0 8 2 amappl15 184 1134 0 1133 1 0 1 1 0 8 0 amappl14 176 1580 0 1573 1 0 1 1 0 8 0 amappl13 168 596 0 596 3 3 0 1 0 8 0 amappl12 160 1117 0 1110 2 1 1 1 0 8 0 amappl11 152 610 0 595 1 0 1 1 0 8 0 amappl10 144 823 0 816 1 0 1 1 0 8 0 amappl9 136 1002 0 999 1 0 1 1 0 8 0 amappl8 128 568 0 533 4 2 2 2 0 8 0 amappl7 120 809 0 799 1 0 1 1 0 8 0 amappl6 112 580 0 571 1 0 1 1 0 8 0 amappl5 104 1396 0 1379 1 0 1 1 0 8 0 amappl4 96 5140 0 5108 2 1 1 2 0 8 0 amappl3 88 2080 0 2066 1 0 1 1 0 8 0 amappl2 80 47237 0 47153 3 1 2 3 0 8 0 amappl1 72 116688 0 116223 26 16 10 20 0 8 0 amappl 80 14271 0 14233 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 57 0 6 1 0 1 1 0 8 0 uaddrrnd 24 5984 0 5943 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 5984 0 5943 1 0 1 1 0 8 0 vmmpekpl 168 35141 0 35107 3 1 2 3 0 8 0 vmmpepl 168 682248 0 680761 130 63 67 79 0 357 2 vmsppl 368 5959 0 5943 2 0 2 2 0 8 0 pdppl 4096 11975 0 11934 6 0 6 6 0 8 0 pvpl 32 1561095 0 1552892 226 140 86 105 0 265 14 pmappl 232 5983 0 5967 6 5 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 607 0 9 18 0 18 18 0 8 0