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 169617 91298 0 0 0 1 syz-executor.0 *318154 41527 0 0 0x4000000 0 syz-executor.1 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(ffff800023d8ea60) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007e24854,fffffd807c99ef40) at alltraps_kern_meltdown+0x7b frag6_input(ffff800023d8edc8,ffff800023d8edd4,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800023d8edc8,ffff800023d8edd4,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800023d8edc8,ffff800023d8edd4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800023d8edc8,ffff800023d8edd4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806d6acf00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806d6acf00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd807ba8af00,ffff800000a41980,fffffd806f6bf5e8,0,0,fffffd806f6bf578) at ip6_output+0xd59 rip6_output(fffffd807ba8af00,fffffd8065d32020,ffff800023d8f138,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff800023d8f1d0, 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic acquiring blockable sleep lock with spinlock or critical section held (kernel_lock) &kernel_lock ddb{0}> 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(ffff800023d8ea60) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007e24854,fffffd807c99ef40) at alltraps_kern_meltdown+0x7b frag6_input(ffff800023d8edc8,ffff800023d8edd4,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800023d8edc8,ffff800023d8edd4,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800023d8edc8,ffff800023d8edd4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800023d8edc8,ffff800023d8edd4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806d6acf00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806d6acf00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd807ba8af00,ffff800000a41980,fffffd806f6bf5e8,0,0,fffffd806f6bf578) at ip6_output+0xd59 rip6_output(fffffd807ba8af00,fffffd8065d32020,ffff800023d8f138,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd8065d32020,9,fffffd807ba8af00,0,0,ffff800020ab13d8) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd8065d32020,0,ffff800023d8f368,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ab13d8,3,ffff800023d8f368,0,ffff800023d8f470) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020ab13d8,ffff800023d8f408,ffff800023d8f470) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800023d8f4e0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023d8f4e0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,38123930010) at Xsyscall+0x128 end of kernel end trace frame: 0x38417712d90, count: -20 ddb{0}> show registers rdi 0xffffffff810d9877 db_enter+0x17 rsi 0x31d6 __ALIGN_SIZE+0x21d6 rbp 0xffff800023d8e7c0 rbx 0xffff800023d8e870 rdx 0x31d7 __ALIGN_SIZE+0x21d7 rcx 0xffff800021b6c000 rax 0xffff800021b6c000 r8 0xffffffff81765703 kprintf+0x173 r9 0x1 r10 0x25 r11 0xd37deb30fd1bed78 r12 0x3000000008 r13 0xffff800023d8e7d0 r14 0x100 r15 0x1 rip 0xffffffff810d9878 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800023d8e7b0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=318154 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020ab0780,0xffff800020ab18d8 process=0xffff800020addc00 user=0xffff800023d8a000, vmspace=0xfffffd807f00bb80 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 91298 169617 69346 0 7 0 syz-executor.0 91298 365920 69346 0 2 0x4000000 syz-executor.0 41527 236257 77955 0 2 0 syz-executor.1 *41527 318154 77955 0 7 0x4000000 syz-executor.1 77955 268665 10478 0 3 0x82 nanosleep syz-executor.1 69346 223288 10478 0 3 0x82 nanosleep syz-executor.0 77647 332099 0 0 3 0x14200 bored sosplice 10478 41848 3711 0 3 0x82 thrsleep syz-fuzzer 10478 298135 3711 0 3 0x4000082 nanosleep syz-fuzzer 10478 159994 3711 0 3 0x4000082 thrsleep syz-fuzzer 10478 424285 3711 0 3 0x4000082 thrsleep syz-fuzzer 10478 429562 3711 0 3 0x4000082 thrsleep syz-fuzzer 10478 211716 3711 0 3 0x4000082 thrsleep syz-fuzzer 10478 116346 3711 0 3 0x4000082 thrsleep syz-fuzzer 10478 249167 3711 0 3 0x4000082 thrsleep syz-fuzzer 10478 344150 3711 0 3 0x4000082 kqread syz-fuzzer 10478 344513 3711 0 3 0x4000082 thrsleep syz-fuzzer 3711 370820 11635 0 3 0x10008a pause ksh 11635 301421 12225 0 3 0x92 select sshd 78372 316545 1 0 3 0x100083 ttyin getty 12225 382211 1 0 3 0x80 select sshd 85026 57160 50273 74 3 0x100092 bpf pflogd 50273 106072 1 0 3 0x80 netio pflogd 95941 368250 59796 73 3 0x100090 kqread syslogd 59796 242853 1 0 3 0x100082 netio syslogd 8652 288942 1 77 3 0x100090 poll dhclient 67915 293740 1 0 3 0x80 poll dhclient 71917 103790 0 0 2 0x14200 zerothread 31027 59672 0 0 3 0x14200 aiodoned aiodoned 93118 320850 0 0 3 0x14200 syncer update 37286 382392 0 0 3 0x14200 cleaner cleaner 53607 178603 0 0 3 0x14200 reaper reaper 4621 421247 0 0 3 0x14200 pgdaemon pagedaemon 3544 44969 0 0 3 0x14200 bored crynlk 45169 358305 0 0 3 0x14200 bored crypto 78381 238781 0 0 3 0x40014200 acpi0 acpi0 16764 203548 0 0 3 0x40014200 idle1 58173 95315 0 0 3 0x14200 bored softnet 21679 458694 0 0 3 0x14200 bored systqmp 45464 271017 0 0 3 0x14200 bored systq 81826 87525 0 0 3 0x40014200 bored softclock 47883 414648 0 0 3 0x40014200 idle0 19773 143159 0 0 3 0x14200 bored smr 1 322982 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: 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 41527 (syz-executor.1) thread 0xffff800020ab13d8 (318154) 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{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9523 6492K 7052K 78643K 12746 0 0 pcb 14 8K 8K 78643K 96 0 0 rtable 111 4K 4K 78643K 544 0 0 ifaddr 57 13K 14K 78643K 170 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1521 0 0 iov 0 0K 16K 78643K 68 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1211 76K 77K 78643K 1997 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 13 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 81 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 826 0 0 sigio 0 0K 0K 78643K 8 0 0 proc 54 51K 71K 78643K 654 0 0 subproc 32 2K 2K 78643K 102 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 90 0 0 in_multi 33 2K 2K 78643K 92 0 0 ether_multi 1 0K 0K 78643K 2 0 0 mrt 1 0K 0K 78643K 2 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 311 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 25K 78643K 3559 0 0 UVM aobj 35 2K 2K 78643K 39 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 76 0 0 NDP 11 0K 0K 78643K 49 0 0 temp 165 3555K 3619K 78643K 17541 0 0 kqueue 0 0K 0K 78643K 6 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 14 0 8 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 41 0 39 1 0 1 1 0 8 0 rtentry 112 89 0 45 2 0 2 2 0 8 0 unpcb 120 272 0 262 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 9860 0 9860 2 2 0 2 0 8 0 tcpcb 544 135 0 130 1 0 1 1 0 8 0 inpcb 280 419 0 411 1 0 1 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 18 0 12 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 ppxss 1128 20 0 20 3 2 1 1 0 8 1 pffrent 40 2 0 2 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 31 0 19 1 0 1 1 0 8 0 pfstkey 112 31 0 19 1 0 1 1 0 8 0 pfstate 328 31 0 19 2 0 2 2 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 256 370 0 176 13 0 13 13 0 8 0 art_table 32 371 0 176 2 0 2 2 0 8 0 art_node 16 88 0 48 1 0 1 1 0 8 0 sysvmsgpl 40 6 0 4 1 0 1 1 0 8 0 semapl 112 79 0 69 1 0 1 1 0 8 0 shmpl 112 37 0 4 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2685 0 1262 47 0 47 47 0 8 0 ffsino 272 2685 0 1262 96 0 96 96 0 8 0 nchpl 144 4022 0 2384 62 0 62 62 0 8 0 uvmvnodes 72 3275 0 0 60 0 60 60 0 8 0 vnodes 200 3275 0 0 173 0 173 173 0 8 0 namei 1024 12081 0 12081 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 11083 0 11083 13 12 1 7 0 8 1 plimitpl 152 78 0 70 1 0 1 1 0 8 0 sigapl 432 1014 0 998 3 1 2 3 0 8 0 futexpl 56 9866 0 9866 1 0 1 1 0 8 1 knotepl 112 245 0 226 1 0 1 1 0 8 0 kqueuepl 104 174 0 172 1 0 1 1 0 8 0 pipepl 112 624 0 605 2 0 2 2 0 8 0 fdescpl 488 1015 0 998 3 0 3 3 0 8 0 filepl 152 5674 0 5573 8 3 5 7 0 8 1 lockfpl 104 248 0 247 2 1 1 1 0 8 0 lockfspl 48 95 0 94 2 1 1 1 0 8 0 sessionpl 112 22 0 11 1 0 1 1 0 8 0 pgrppl 48 30 0 19 1 0 1 1 0 8 0 ucredpl 96 809 0 800 1 0 1 1 0 8 0 zombiepl 144 998 0 998 2 1 1 1 0 8 1 processpl 896 1031 0 998 4 0 4 4 0 8 0 procpl 632 2594 0 2550 6 1 5 5 0 8 1 srpgc 64 8 0 8 4 3 1 1 0 8 1 sosppl 128 10 0 10 2 1 1 1 0 8 1 sockpl 384 743 0 723 5 2 3 4 0 8 0 mcl64k 65536 8 0 0 1 0 1 1 0 8 0 mcl12k 12288 10 0 0 1 0 1 1 0 8 0 mcl9k 9216 5 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 218 0 0 25 0 25 25 0 8 0 mtagpl 80 15 0 0 1 0 1 1 0 8 0 mbufpl 256 254 0 0 15 0 15 15 0 8 0 bufpl 256 7524 0 1172 397 0 397 397 0 8 0 anonpl 16 101526 0 91154 80 29 51 67 0 124 0 amapchunkpl 152 5619 0 5483 10 3 7 9 0 158 0 amappl16 192 4292 0 3626 50 16 34 44 0 8 0 amappl15 184 112 0 111 1 0 1 1 0 8 0 amappl14 176 553 0 547 1 0 1 1 0 8 0 amappl13 168 211 0 209 2 1 1 1 0 8 0 amappl12 160 6 0 6 1 1 0 1 0 8 0 amappl11 152 120 0 105 1 0 1 1 0 8 0 amappl10 144 83 0 80 1 0 1 1 0 8 0 amappl9 136 650 0 647 1 0 1 1 0 8 0 amappl8 128 215 0 191 1 0 1 1 0 8 0 amappl7 120 57 0 48 1 0 1 1 0 8 0 amappl6 112 101 0 93 1 0 1 1 0 8 0 amappl5 104 169 0 154 1 0 1 1 0 8 0 amappl4 96 1272 0 1241 2 1 1 2 0 8 0 amappl3 88 575 0 564 1 0 1 1 0 8 0 amappl2 80 7040 0 6957 3 1 2 3 0 8 0 amappl1 72 32011 0 31558 26 16 10 20 0 8 0 amappl 80 2924 0 2878 2 0 2 2 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 38 0 4 1 0 1 1 0 8 0 uaddrrnd 24 1015 0 998 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1015 0 998 1 0 1 1 0 8 0 vmmpekpl 168 11607 0 11573 2 0 2 2 0 8 0 vmmpepl 168 129661 0 127750 149 46 103 107 0 357 19 vmsppl 368 1014 0 998 2 0 2 2 0 8 0 pdppl 4096 2037 0 1996 7 1 6 6 0 8 0 pvpl 32 301957 0 288348 189 55 134 163 0 265 8 pmappl 232 1014 0 998 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 569 0 5 17 0 17 17 0 8 0