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 *496603 28795 0 0 0x4000000 1 syz-executor.0 90109 33010 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(ffffffff8264be40,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8264bc38) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800023b8c510) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007e0c854,fffffd8064798f10) at alltraps_kern_meltdown+0x7b frag6_input(ffff800023b8c878,ffff800023b8c884,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800023b8c878,ffff800023b8c884,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800023b8c878,ffff800023b8c884,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800023b8c878,ffff800023b8c884,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd8067fa0c00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd8067fa0c00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806903b300,ffff800000ab8600,fffffd806f6b6070,0,0,fffffd806f6b6000) at ip6_output+0xd59 rip6_output(fffffd806903b300,fffffd8078154b00,ffff800023b8cbe8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff800023b8cc80, 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(ffffffff8264be40,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff8264bc38) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800023b8c510) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007e0c854,fffffd8064798f10) at alltraps_kern_meltdown+0x7b frag6_input(ffff800023b8c878,ffff800023b8c884,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800023b8c878,ffff800023b8c884,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800023b8c878,ffff800023b8c884,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800023b8c878,ffff800023b8c884,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd8067fa0c00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd8067fa0c00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806903b300,ffff800000ab8600,fffffd806f6b6070,0,0,fffffd806f6b6000) at ip6_output+0xd59 rip6_output(fffffd806903b300,fffffd8078154b00,ffff800023b8cbe8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd8078154b00,9,fffffd806903b300,0,0,ffff800020ace550) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd8078154b00,0,ffff800023b8ce18,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ace550,3,ffff800023b8ce18,0,ffff800023b8cf20) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020ace550,ffff800023b8ceb8,ffff800023b8cf20) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800023b8cf90) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023b8cf90) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,5fa04f38010) at Xsyscall+0x128 end of kernel end trace frame: 0x5fc16c9ad80, count: -20 ddb{1}> show registers rdi 0xffffffff810d9877 db_enter+0x17 rsi 0x291f __ALIGN_SIZE+0x191f rbp 0xffff800023b8c270 rbx 0xffff800023b8c320 rdx 0x2920 __ALIGN_SIZE+0x1920 rcx 0xffff800023bb4000 rax 0xffff800023bb4000 r8 0xffffffff81765703 kprintf+0x173 r9 0x1 r10 0x25 r11 0x95a1ea1fed55d1b4 r12 0x3000000008 r13 0xffff800023b8c280 r14 0x100 r15 0x1 rip 0xffffffff810d9878 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800023b8c260 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=496603 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020acfb88,0xffff800020ace070 process=0xffff800020add880 user=0xffff800023b88000, vmspace=0xfffffd807f00ba10 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 28795 192099 65935 0 2 0 syz-executor.0 *28795 496603 65935 0 7 0x4000000 syz-executor.0 28795 1637 65935 0 3 0x4000080 fsleep syz-executor.0 58727 330205 32952 0 3 0x90 nanosleep syz-executor.1 58727 279508 32952 0 3 0x4000090 fsleep syz-executor.1 58727 298918 32952 0 3 0x4000090 fsleep syz-executor.1 11614 492845 1 0 3 0x80 nanosleep init 32952 383204 37930 0 3 0x82 nanosleep syz-executor.1 65935 334961 37930 0 3 0x82 nanosleep syz-executor.0 4108 250485 0 0 3 0x14200 bored sosplice 37930 371244 25185 0 3 0x82 thrsleep syz-fuzzer 37930 457333 25185 0 3 0x4000082 thrsleep syz-fuzzer 37930 151489 25185 0 3 0x4000082 thrsleep syz-fuzzer 37930 375515 25185 0 3 0x4000082 kqread syz-fuzzer 37930 35072 25185 0 3 0x4000082 thrsleep syz-fuzzer 37930 465375 25185 0 3 0x4000082 thrsleep syz-fuzzer 37930 281720 25185 0 3 0x4000082 thrsleep syz-fuzzer 37930 90015 25185 0 3 0x4000082 thrsleep syz-fuzzer 37930 19149 25185 0 3 0x4000082 thrsleep syz-fuzzer 37930 463406 25185 0 3 0x4000082 thrsleep syz-fuzzer 25185 136409 68412 0 3 0x10008a pause ksh 68412 406348 95579 0 3 0x92 select sshd 95579 112307 1 0 3 0x80 select sshd 18096 361089 27939 74 3 0x100092 bpf pflogd 27939 377785 1 0 3 0x80 netio pflogd 81503 116325 61594 73 3 0x100090 kqread syslogd 61594 509093 1 0 3 0x100082 netio syslogd 24485 297337 1 77 3 0x100090 poll dhclient 26740 212150 1 0 3 0x80 poll dhclient 26145 336570 0 0 3 0x14200 pgzero zerothread 15489 291807 0 0 3 0x14200 aiodoned aiodoned 91821 524148 0 0 3 0x14200 syncer update 19983 74978 0 0 3 0x14200 cleaner cleaner 54110 383324 0 0 3 0x14200 reaper reaper 39878 499153 0 0 3 0x14200 pgdaemon pagedaemon 1430 368334 0 0 3 0x14200 bored crynlk 7914 168265 0 0 3 0x14200 bored crypto 8127 10864 0 0 3 0x40014200 acpi0 acpi0 60429 80135 0 0 3 0x40014200 idle1 17520 144678 0 0 3 0x14200 bored softnet 76364 100038 0 0 3 0x14200 bored systqmp 8510 56993 0 0 3 0x14200 bored systq 33010 90109 0 0 7 0x40014200 softclock 77238 421657 0 0 3 0x40014200 idle0 43715 132410 0 0 3 0x14200 bored smr 1 35501 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 (0xffffffff8251c660) #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 28795 (syz-executor.0) thread 0xffff800020ace550 (496603) exclusive rwlock netlock r = 0 (0xffffffff824882c8) #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 (0xffffffff8251c660) #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 9611 6590K 8127K 78643K 30103 0 0 pcb 14 8K 8K 78643K 801 0 0 rtable 113 4K 5K 78643K 2248 0 0 ifaddr 87 19K 20K 78643K 862 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1849 0 0 iov 0 0K 24K 78643K 754 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1210 76K 77K 78643K 8174 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 119 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 827 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 7687 0 0 sigio 0 0K 0K 78643K 113 0 0 proc 47 38K 71K 78643K 1847 0 0 subproc 32 2K 2K 78643K 333 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 672 0 0 in_multi 33 2K 2K 78643K 461 0 0 ether_multi 1 0K 0K 78643K 41 0 0 mrt 2 0K 0K 78643K 23 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 96 424K 424K 78643K 96 0 0 exec 0 0K 1K 78643K 1032 0 0 pfkey data 0 0K 4K 78643K 8 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 110 22K 32K 78643K 25397 0 0 UVM aobj 130 7K 7K 78643K 152 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 859 0 0 NDP 21 0K 0K 78643K 260 0 0 temp 235 3557K 4196K 78643K 113165 0 0 kqueue 0 0K 0K 78643K 52 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 45 0 38 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 305 0 303 1 0 1 1 0 8 0 rtentry 112 242 0 197 2 0 2 2 0 8 0 unpcb 120 2515 0 2505 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 10183 0 10183 2 2 0 2 0 8 0 tcpcb 544 1441 0 1436 1 0 1 1 0 8 0 inpcb 280 4237 0 4227 16 15 1 2 0 8 0 rttmr 72 3 0 3 3 2 1 1 0 8 1 ip6q 72 5 0 4 4 3 1 1 0 8 0 ip6af 48 6 0 5 3 2 1 1 0 8 0 nd6 48 57 0 51 1 0 1 1 0 8 0 pkpcb 40 38 0 38 13 13 0 1 0 8 0 swfcl 56 6 0 0 1 0 1 1 0 8 0 ppxss 1128 137 0 137 21 20 1 1 0 8 1 pffrag 232 7 0 7 4 4 0 1 0 482 0 pffrnode 88 7 0 7 4 4 0 1 0 8 0 pffrent 40 16 0 16 4 4 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 24 196 0 170 1 0 1 1 0 8 0 pfstkey 112 197 0 171 1 0 1 1 0 8 0 pfstate 328 197 0 171 4 1 3 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 256 995 0 800 14 1 13 13 0 8 0 art_table 32 996 0 800 2 0 2 2 0 8 0 art_node 16 239 0 198 1 0 1 1 0 8 0 sysvmsgpl 40 9 0 4 2 1 1 1 0 8 0 semapl 112 825 0 815 1 0 1 1 0 8 0 shmpl 112 150 0 22 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 13337 0 11895 47 0 47 47 0 8 0 ffsino 272 13337 0 11895 97 0 97 97 0 8 0 nchpl 144 24358 0 22724 62 0 62 62 0 8 0 uvmvnodes 72 6217 0 0 114 0 114 114 0 8 0 vnodes 200 6217 0 0 328 0 328 328 0 8 0 namei 1024 78250 0 78250 5 4 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 19 0 19 13 12 1 1 0 8 1 scxspl 192 72573 0 72573 30 28 2 7 0 8 2 plimitpl 152 675 0 668 1 0 1 1 0 8 0 sigapl 432 7838 0 7822 3 1 2 3 0 8 0 futexpl 56 98587 0 98584 2 1 1 1 0 8 0 knotepl 112 1528 0 1509 1 0 1 1 0 8 0 kqueuepl 104 1630 0 1628 1 0 1 1 0 8 0 pipepl 112 4292 0 4273 10 8 2 2 0 8 1 fdescpl 488 7839 0 7822 3 0 3 3 0 8 0 filepl 152 46121 0 46022 25 19 6 7 0 8 2 lockfpl 104 2389 0 2389 6 5 1 1 0 8 1 lockfspl 48 781 0 781 6 5 1 1 0 8 1 sessionpl 112 36 0 26 1 0 1 1 0 8 0 pgrppl 48 105 0 95 1 0 1 1 0 8 0 ucredpl 96 8867 0 8857 1 0 1 1 0 8 0 zombiepl 144 7823 0 7823 5 4 1 1 0 8 1 processpl 896 7856 0 7823 4 0 4 4 0 8 0 procpl 632 23679 0 23633 13 8 5 5 0 8 0 srpgc 64 37 0 37 18 17 1 1 0 8 1 sosppl 128 77 0 77 20 19 1 1 0 8 1 sockpl 384 7165 0 7145 18 14 4 4 0 8 1 mcl64k 65536 355 0 0 41 25 16 34 0 8 0 mcl16k 16384 17 0 0 3 1 2 3 0 8 0 mcl12k 12288 21 0 0 2 0 2 2 0 8 0 mcl9k 9216 27 0 0 2 1 1 2 0 8 0 mcl8k 8192 17 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 237 0 0 28 4 24 28 0 8 0 mtagpl 80 72 0 0 1 0 1 1 0 8 0 mbufpl 256 618 0 0 23 0 23 23 0 8 0 bufpl 256 24556 0 17537 439 0 439 439 0 8 0 anonpl 16 735908 0 723341 162 103 59 68 0 124 0 amapchunkpl 152 46519 0 46409 73 63 10 12 0 158 4 amappl16 192 40105 0 39401 201 164 37 48 0 8 0 amappl15 184 1391 0 1391 4 4 0 1 0 8 0 amappl14 176 1809 0 1803 1 0 1 1 0 8 0 amappl13 168 2852 0 2851 3 2 1 1 0 8 0 amappl12 160 276 0 276 2 2 0 1 0 8 0 amappl11 152 580 0 564 1 0 1 1 0 8 0 amappl10 144 117 0 112 1 0 1 1 0 8 0 amappl9 136 1852 0 1844 1 0 1 1 0 8 0 amappl8 128 1370 0 1330 2 0 2 2 0 8 0 amappl7 120 106 0 98 1 0 1 1 0 8 0 amappl6 112 550 0 540 1 0 1 1 0 8 0 amappl5 104 577 0 563 1 0 1 1 0 8 0 amappl4 96 9210 0 9180 2 1 1 2 0 8 0 amappl3 88 3236 0 3226 1 0 1 1 0 8 0 amappl2 80 60845 0 60768 3 1 2 3 0 8 0 amappl1 72 176708 0 176273 25 15 10 20 0 8 0 amappl 80 24260 0 24220 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 64 151 0 22 3 0 3 3 0 8 0 uaddrrnd 24 7839 0 7822 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7839 0 7822 1 0 1 1 0 8 0 vmmpekpl 168 58593 0 58558 2 0 2 2 0 8 0 vmmpepl 168 954060 0 952126 328 239 89 106 0 357 0 vmsppl 368 7838 0 7822 2 0 2 2 0 8 0 pdppl 4096 15685 0 15644 8 2 6 6 0 8 0 pvpl 32 1913891 0 1898189 375 223 152 167 0 265 9 pmappl 232 7838 0 7822 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 675 0 41 19 0 19 19 0 8 0