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 *236020 6609 0 0 0x4000000 1 syz-executor.0 469570 128 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(ffffffff8265f5f8,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8265f3f0) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff80002275d2a0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dec854,fffffd8066157f40) at alltraps_kern_meltdown+0x7b frag6_input(ffff80002275d608,ffff80002275d614,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff80002275d608,ffff80002275d614,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff80002275d608,ffff80002275d614,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff80002275d608,ffff80002275d614,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd80634b9e00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd80634b9e00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd8063f58b00,ffff800000a95200,fffffd806f6b4c78,0,0,fffffd806f6b4c08) at ip6_output+0xd59 rip6_output(fffffd8063f58b00,fffffd806f6b5480,ffff80002275d978,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff80002275da10, 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(ffffffff8265f5f8,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8265f3f0) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff80002275d2a0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dec854,fffffd8066157f40) at alltraps_kern_meltdown+0x7b frag6_input(ffff80002275d608,ffff80002275d614,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff80002275d608,ffff80002275d614,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff80002275d608,ffff80002275d614,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff80002275d608,ffff80002275d614,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd80634b9e00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd80634b9e00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd8063f58b00,ffff800000a95200,fffffd806f6b4c78,0,0,fffffd806f6b4c08) at ip6_output+0xd59 rip6_output(fffffd8063f58b00,fffffd806f6b5480,ffff80002275d978,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd806f6b5480,9,fffffd8063f58b00,0,0,ffff800020a5ec60) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd806f6b5480,0,ffff80002275dba8,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020a5ec60,3,ffff80002275dba8,0,ffff80002275dcb0) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020a5ec60,ffff80002275dc48,ffff80002275dcb0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff80002275dd20) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff80002275dd20) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,e360dd42010) at Xsyscall+0x128 end of kernel end trace frame: 0xe382c6a8a80, count: -20 ddb{1}> show registers rdi 0xffffffff81d56a37 db_enter+0x17 rsi 0x377f __ALIGN_SIZE+0x277f rbp 0xffff80002275d000 rbx 0xffff80002275d0b0 rdx 0x3780 __ALIGN_SIZE+0x2780 rcx 0xffff800022766000 rax 0xffff800022766000 r8 0xffffffff812e94e3 kprintf+0x173 r9 0x1 r10 0x25 r11 0xb652b7045464f2ce r12 0x3000000008 r13 0xffff80002275d010 r14 0x100 r15 0x1 rip 0xffffffff81d56a38 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002275cff0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=236020 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020a5f640,0xffffffff826641e8 process=0xffff800020a8a710 user=0xffff800022758000, vmspace=0xfffffd807f00bb80 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 6609 80777 20397 0 2 0 syz-executor.0 * 6609 236020 20397 0 7 0x4000000 syz-executor.0 20397 207060 75790 0 2 0x482 syz-executor.0 88764 174813 75790 0 2 0x482 syz-executor.1 76051 306572 1 0 3 0x100083 ttyin getty 35288 324424 0 0 3 0x14200 bored sosplice 75790 280923 56994 0 3 0x82 thrsleep syz-fuzzer 75790 339514 56994 0 3 0x4000082 nanosleep syz-fuzzer 75790 222509 56994 0 3 0x4000082 thrsleep syz-fuzzer 75790 299634 56994 0 3 0x4000082 thrsleep syz-fuzzer 75790 343501 56994 0 3 0x4000082 thrsleep syz-fuzzer 75790 298589 56994 0 3 0x4000082 thrsleep syz-fuzzer 75790 192629 56994 0 3 0x4000082 thrsleep syz-fuzzer 75790 290052 56994 0 3 0x4000082 thrsleep syz-fuzzer 75790 179631 56994 0 3 0x4000082 thrsleep syz-fuzzer 75790 55823 56994 0 3 0x4000082 kqread syz-fuzzer 56994 432504 43609 0 3 0x10008a pause ksh 43609 505797 72843 0 3 0x92 select sshd 72843 384623 1 0 3 0x80 select sshd 71650 408034 22949 74 3 0x100092 bpf pflogd 22949 353578 1 0 3 0x80 netio pflogd 9071 405957 8461 73 3 0x100090 kqread syslogd 8461 90952 1 0 3 0x100082 netio syslogd 40048 327180 0 0 3 0x14200 pgzero zerothread 21863 517834 0 0 3 0x14200 aiodoned aiodoned 30168 359103 0 0 3 0x14200 syncer update 13696 71599 0 0 3 0x14200 cleaner cleaner 16989 248692 0 0 3 0x14200 reaper reaper 13716 18512 0 0 3 0x14200 pgdaemon pagedaemon 12547 56513 0 0 3 0x14200 bored crynlk 95122 119701 0 0 3 0x14200 bored crypto 99508 316261 0 0 3 0x40014200 acpi0 acpi0 22503 251238 0 0 3 0x40014200 idle1 6295 515119 0 0 3 0x14200 bored softnet 8836 31117 0 0 3 0x14200 bored systqmp 77693 138507 0 0 3 0x14200 bored systq 128 469570 0 0 7 0x40014200 softclock 72400 335242 0 0 3 0x40014200 idle0 94206 293928 0 0 3 0x14200 bored smr 1 288114 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 (0xffffffff824bae40) #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 6609 (syz-executor.0) thread 0xffff800020a5ec60 (236020) exclusive rwlock netlock r = 0 (0xffffffff824c5488) #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 (0xffffffff824bae40) #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 9568 6405K 14719K 78643K 20770 0 0 pcb 14 8K 8K 78643K 512 0 0 rtable 111 4K 5K 78643K 1093 0 0 ifaddr 74 18K 21K 78643K 530 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1685 0 0 iov 0 0K 20K 78643K 485 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1207 76K 77K 78643K 5036 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 33 0 0 VM map 2 1K 1K 78643K 8 0 0 sem 12 0K 0K 78643K 505 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 4629 0 0 sigio 0 0K 0K 78643K 56 0 0 proc 55 51K 83K 78643K 1412 0 0 subproc 32 2K 2K 78643K 276 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 378 0 0 in_multi 33 2K 2K 78643K 342 0 0 ether_multi 1 0K 0K 78643K 30 0 0 mrt 0 0K 0K 78643K 26 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 709 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 97 21K 30K 78643K 15886 0 0 UVM aobj 130 5K 5K 78643K 146 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 2 0K 0K 78643K 454 0 0 NDP 17 0K 0K 78643K 163 0 0 temp 208 3556K 4187K 78643K 60644 0 0 kqueue 0 0K 0K 78643K 36 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 36 0 30 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 182 0 182 13 12 1 1 0 8 1 rtentry 112 208 0 164 2 0 2 2 0 8 0 unpcb 120 1286 0 1278 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 5455 0 5455 1 1 0 1 0 8 0 tcpcb 544 828 0 823 1 0 1 1 0 8 0 inpcb 280 2482 0 2477 5 4 1 2 0 8 0 rttmr 72 5 0 5 5 5 0 1 0 8 0 ip6q 72 1 0 0 1 0 1 1 0 8 0 ip6af 48 1 0 0 1 0 1 1 0 8 0 nd6 48 48 0 42 1 0 1 1 0 8 0 pkpcb 40 20 0 20 7 6 1 1 0 8 1 ppxss 1128 85 0 85 16 15 1 1 0 8 1 pffrag 232 10 0 10 5 5 0 1 0 482 0 pffrnode 88 10 0 10 5 5 0 1 0 8 0 pffrent 40 20 0 20 5 5 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 24 116 0 102 1 0 1 1 0 8 0 pfstkey 112 116 0 102 1 0 1 1 0 8 0 pfstate 328 116 0 102 4 2 2 3 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 256 842 0 651 16 4 12 13 0 8 0 art_table 32 843 0 651 2 0 2 2 0 8 0 art_node 16 205 0 165 1 0 1 1 0 8 0 sysvmsgpl 40 34 0 21 1 0 1 1 0 8 0 semapl 112 501 0 491 1 0 1 1 0 8 0 shmpl 112 144 0 16 5 1 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 8840 0 7405 47 0 47 47 0 8 0 ffsino 272 8840 0 7405 97 1 96 97 0 8 0 nchpl 144 15620 0 13986 62 0 62 62 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 200 5926 0 0 312 0 312 312 0 8 0 namei 1024 48674 0 48674 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 552 6 0 6 3 3 0 1 0 8 0 scsiplug 64 10 0 10 8 8 0 1 0 8 0 scxspl 192 69409 0 69409 29 28 1 7 0 8 1 plimitpl 152 398 0 390 1 0 1 1 0 8 0 sigapl 432 4790 0 4777 3 1 2 3 0 8 0 futexpl 56 61889 0 61889 1 0 1 1 0 8 1 knotepl 112 956 0 937 2 1 1 2 0 8 0 kqueuepl 104 796 0 794 1 0 1 1 0 8 0 pipepl 112 2484 0 2465 5 4 1 2 0 8 0 fdescpl 488 4791 0 4777 3 0 3 3 0 8 0 filepl 152 27290 0 27200 12 7 5 6 0 8 1 lockfpl 104 2719 0 2719 7 6 1 1 0 8 1 lockfspl 48 965 0 965 7 6 1 1 0 8 1 sessionpl 112 35 0 26 1 0 1 1 0 8 0 pgrppl 48 70 0 61 1 0 1 1 0 8 0 ucredpl 96 4782 0 4773 1 0 1 1 0 8 0 zombiepl 144 4778 0 4777 3 2 1 1 0 8 0 processpl 896 4808 0 4777 4 0 4 4 0 8 0 procpl 632 13980 0 13939 9 5 4 5 0 8 0 srpgc 64 33 0 33 13 13 0 1 0 8 0 sosppl 128 33 0 33 13 13 0 1 0 8 0 sockpl 384 3991 0 3978 15 13 2 4 0 8 0 mcl64k 65536 266 0 0 34 11 23 34 0 8 1 mcl16k 16384 13 0 0 2 0 2 2 0 8 0 mcl12k 12288 28 0 0 2 0 2 2 0 8 0 mcl9k 9216 14 0 0 1 0 1 1 0 8 0 mcl8k 8192 7 0 0 1 0 1 1 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 8 0 0 1 0 1 1 0 8 0 mcl2k 2048 164 0 0 19 0 19 19 0 8 1 mtagpl 80 47 0 0 1 0 1 1 0 8 0 mbufpl 256 527 0 0 24 0 24 24 0 8 0 bufpl 256 28666 0 21647 439 0 439 439 0 8 0 anonpl 16 478989 0 466394 173 105 68 69 0 124 14 amapchunkpl 152 27661 0 27561 41 31 10 18 0 158 5 amappl16 192 25322 0 24611 146 98 48 49 0 8 11 amappl15 184 340 0 340 2 2 0 1 0 8 0 amappl14 176 715 0 707 1 0 1 1 0 8 0 amappl13 168 751 0 751 3 3 0 1 0 8 0 amappl12 160 110 0 110 3 3 0 1 0 8 0 amappl11 152 2042 0 2033 1 0 1 1 0 8 0 amappl10 144 490 0 487 1 0 1 1 0 8 0 amappl9 136 1361 0 1356 1 0 1 1 0 8 0 amappl8 128 891 0 860 3 1 2 2 0 8 0 amappl7 120 480 0 471 1 0 1 1 0 8 0 amappl6 112 1983 0 1973 1 0 1 1 0 8 0 amappl5 104 760 0 749 1 0 1 1 0 8 0 amappl4 96 4956 0 4926 2 1 1 2 0 8 0 amappl3 88 798 0 787 1 0 1 1 0 8 0 amappl2 80 37589 0 37523 3 0 3 3 0 8 0 amappl1 72 110685 0 110285 25 16 9 20 0 8 0 amappl 80 14466 0 14433 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 64 145 0 16 4 1 3 3 0 8 0 uaddrrnd 24 4797 0 4777 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4797 0 4777 1 0 1 1 0 8 0 vmmpekpl 168 33530 0 33496 2 0 2 2 0 8 0 vmmpepl 168 591877 0 590115 295 201 94 111 0 357 10 vmsppl 368 4790 0 4777 2 0 2 2 0 8 0 pdppl 4096 9601 0 9566 7 1 6 6 0 8 0 pvpl 32 1330663 0 1314953 353 187 166 173 0 265 31 pmappl 232 4796 0 4783 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 656 0 22 19 0 19 19 0 8 0