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 390899 49046 0 0 0 1 syz-executor.1 * 99453 49046 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(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(ffff8000231b08c0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd807eb9e054,fffffd8068da6eb8) at alltraps_kern_meltdown+0x7b frag6_input(ffff8000231b0c28,ffff8000231b0c34,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff8000231b0c28,ffff8000231b0c34,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff8000231b0c28,ffff8000231b0c34,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff8000231b0c28,ffff8000231b0c34,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806d1ecf00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806d1ecf00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806772d800,ffff800000a41080,fffffd806f6c0818,0,0,fffffd806f6c07a8) at ip6_output+0xd59 rip6_output(fffffd806772d800,fffffd8067065ac0,ffff8000231b0f98,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff8000231b1030, 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(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(ffff8000231b08c0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd807eb9e054,fffffd8068da6eb8) at alltraps_kern_meltdown+0x7b frag6_input(ffff8000231b0c28,ffff8000231b0c34,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff8000231b0c28,ffff8000231b0c34,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff8000231b0c28,ffff8000231b0c34,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff8000231b0c28,ffff8000231b0c34,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806d1ecf00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806d1ecf00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806772d800,ffff800000a41080,fffffd806f6c0818,0,0,fffffd806f6c07a8) at ip6_output+0xd59 rip6_output(fffffd806772d800,fffffd8067065ac0,ffff8000231b0f98,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd8067065ac0,9,fffffd806772d800,0,0,ffff800020abf3d8) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd8067065ac0,0,ffff8000231b11c8,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020abf3d8,5,ffff8000231b11c8,0,ffff8000231b12d0) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020abf3d8,ffff8000231b1268,ffff8000231b12d0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff8000231b1340) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff8000231b1340) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,669bbebb010) at Xsyscall+0x128 end of kernel end trace frame: 0x66c7552bdb0, count: -20 ddb{0}> show registers rdi 0xffffffff81d56a37 db_enter+0x17 rsi 0x2f64 __ALIGN_SIZE+0x1f64 rbp 0xffff8000231b0620 rbx 0xffff8000231b06d0 rdx 0x2f65 __ALIGN_SIZE+0x1f65 rcx 0xffff800021b7c000 rax 0xffff800021b7c000 r8 0xffffffff812e94e3 kprintf+0x173 r9 0x1 r10 0x25 r11 0x68fa2fb6be169895 r12 0x3000000008 r13 0xffff8000231b0630 r14 0x100 r15 0x1 rip 0xffffffff81d56a38 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000231b0610 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=99453 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020ac0500,0xffffffff826641e8 process=0xffff800020adce00 user=0xffff8000231ac000, vmspace=0xfffffd807f00b8a0 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 49046 390899 8877 0 7 0 syz-executor.1 *49046 99453 8877 0 7 0x4000000 syz-executor.1 51492 304699 89420 0 3 0x80 nanosleep syz-executor.0 51492 412896 89420 0 3 0x4000080 ttyout syz-executor.0 51492 217859 89420 0 3 0x4000080 fsleep syz-executor.0 89420 9649 79576 0 3 0x82 nanosleep syz-executor.0 34594 418639 1 0 3 0x100083 ttyin getty 8877 337595 79576 0 3 0x82 nanosleep syz-executor.1 97937 509661 0 0 3 0x14200 bored sosplice 79576 482919 10106 0 3 0x82 thrsleep syz-fuzzer 79576 284444 10106 0 3 0x4000082 nanosleep syz-fuzzer 79576 158915 10106 0 3 0x4000082 kqread syz-fuzzer 79576 407711 10106 0 3 0x4000082 thrsleep syz-fuzzer 79576 45319 10106 0 3 0x4000082 thrsleep syz-fuzzer 79576 363540 10106 0 3 0x4000082 thrsleep syz-fuzzer 79576 3671 10106 0 3 0x4000082 thrsleep syz-fuzzer 79576 234180 10106 0 3 0x4000082 thrsleep syz-fuzzer 79576 193400 10106 0 3 0x4000082 thrsleep syz-fuzzer 79576 217663 10106 0 3 0x4000082 thrsleep syz-fuzzer 10106 358787 49630 0 3 0x10008a pause ksh 49630 113876 85392 0 3 0x92 select sshd 85392 61156 1 0 3 0x80 select sshd 63383 31183 69784 74 3 0x100092 bpf pflogd 69784 228142 1 0 3 0x80 netio pflogd 38593 460354 89428 73 3 0x100090 kqread syslogd 89428 168522 1 0 3 0x100082 netio syslogd 66193 38675 1 77 3 0x100090 poll dhclient 4692 253771 1 0 3 0x80 poll dhclient 75254 509736 0 0 3 0x14200 pgzero zerothread 29130 97774 0 0 3 0x14200 aiodoned aiodoned 31947 349318 0 0 3 0x14200 syncer update 76457 363571 0 0 3 0x14200 cleaner cleaner 10666 72191 0 0 3 0x14200 reaper reaper 6127 507062 0 0 3 0x14200 pgdaemon pagedaemon 91862 321519 0 0 3 0x14200 bored crynlk 39625 215417 0 0 3 0x14200 bored crypto 97273 183726 0 0 3 0x40014200 acpi0 acpi0 89326 42606 0 0 3 0x40014200 idle1 58367 322542 0 0 3 0x14200 bored softnet 66514 475166 0 0 3 0x14200 bored systqmp 13923 492540 0 0 3 0x14200 bored systq 19535 327257 0 0 3 0x40014200 bored softclock 22682 43872 0 0 3 0x40014200 idle0 4672 366927 0 0 3 0x14200 bored smr 1 390768 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 (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 49046 (syz-executor.1) thread 0xffff800020abf3d8 (99453) 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{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9593 6468K 7216K 78643K 18410 0 0 pcb 14 8K 8K 78643K 375 0 0 rtable 87 3K 4K 78643K 1323 0 0 ifaddr 78 16K 18K 78643K 489 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1655 0 0 iov 0 0K 24K 78643K 309 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1204 76K 77K 78643K 4120 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 43 0 0 VM map 2 1K 1K 78643K 4 0 0 sem 12 0K 0K 78643K 368 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 3224 0 0 sigio 0 0K 0K 78643K 32 0 0 proc 54 51K 83K 78643K 1132 0 0 subproc 32 2K 2K 78643K 224 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 346 0 0 in_multi 22 1K 2K 78643K 264 0 0 ether_multi 1 0K 0K 78643K 22 0 0 mrt 0 0K 0K 78643K 15 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 602 0 0 pfkey data 0 0K 0K 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 104 21K 30K 78643K 11377 0 0 UVM aobj 123 4K 4K 78643K 134 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 365 0 0 NDP 19 0K 0K 78643K 147 0 0 temp 221 3556K 3632K 78643K 37509 0 0 kqueue 0 0K 0K 78643K 22 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 29 0 25 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 120 0 118 1 0 1 1 0 8 0 rtentry 112 173 0 140 2 1 1 2 0 8 0 unpcb 120 1046 0 1036 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 4067 0 4067 1 1 0 1 0 8 0 tcpcb 544 650 0 645 1 0 1 1 0 8 0 inpcb 280 1886 0 1878 5 4 1 2 0 8 0 rttmr 72 3 0 3 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 39 0 36 1 0 1 1 0 8 0 pkpcb 40 6 0 6 3 3 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 73 0 73 9 8 1 1 0 8 1 pffrag 232 5 0 5 3 3 0 1 0 482 0 pffrnode 88 5 0 5 3 3 0 1 0 8 0 pffrent 40 10 0 10 3 3 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 24 102 0 81 1 0 1 1 0 8 0 pfstkey 112 102 0 81 1 0 1 1 0 8 0 pfstate 328 102 0 81 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 256 730 0 583 18 8 10 14 0 8 0 art_table 32 731 0 583 2 0 2 2 0 8 0 art_node 16 169 0 139 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 3 2 1 1 1 0 8 0 semapl 112 366 0 356 1 0 1 1 0 8 0 shmpl 112 132 0 11 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 6351 0 4927 47 0 47 47 0 8 0 ffsino 272 6351 0 4927 96 0 96 96 0 8 0 nchpl 144 10953 0 9316 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 35363 0 35363 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 552 2 0 2 1 1 0 1 0 8 0 scsiplug 64 6 0 6 5 5 0 1 0 8 0 scxspl 192 30625 0 30625 24 23 1 7 0 8 1 plimitpl 152 335 0 326 1 0 1 1 0 8 0 sigapl 432 3395 0 3379 3 1 2 3 0 8 0 futexpl 56 40348 0 40347 2 1 1 1 0 8 0 knotepl 112 787 0 768 1 0 1 1 0 8 0 kqueuepl 104 668 0 666 1 0 1 1 0 8 0 pipepl 112 1968 0 1947 6 5 1 2 0 8 0 fdescpl 488 3396 0 3379 3 0 3 3 0 8 0 filepl 152 19891 0 19785 11 6 5 7 0 8 0 lockfpl 104 1055 0 1055 3 2 1 1 0 8 1 lockfspl 48 361 0 361 3 2 1 1 0 8 1 sessionpl 112 33 0 22 1 0 1 1 0 8 0 pgrppl 48 60 0 49 1 0 1 1 0 8 0 ucredpl 96 3501 0 3492 1 0 1 1 0 8 0 zombiepl 144 3381 0 3381 2 1 1 1 0 8 1 processpl 896 3414 0 3381 4 0 4 4 0 8 0 procpl 632 10037 0 9992 12 7 5 5 0 8 1 srpgc 64 27 0 27 12 11 1 1 0 8 1 sosppl 128 59 0 59 13 13 0 1 0 8 0 sockpl 384 3101 0 3081 9 6 3 4 0 8 0 mcl64k 65536 263 0 0 33 17 16 33 0 8 1 mcl16k 16384 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 13 0 0 1 0 1 1 0 8 0 mcl8k 8192 11 0 0 2 0 2 2 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 170 0 0 20 2 18 20 0 8 0 mtagpl 80 43 0 0 1 0 1 1 0 8 0 mbufpl 256 465 0 0 24 1 23 24 0 8 0 bufpl 256 14931 0 7912 439 0 439 439 0 8 0 anonpl 16 320138 0 308688 131 72 59 69 0 124 1 amapchunkpl 152 20049 0 19937 25 19 6 10 0 158 0 amappl16 192 16676 0 15955 115 77 38 48 0 8 1 amappl15 184 816 0 815 1 0 1 1 0 8 0 amappl14 176 826 0 819 1 0 1 1 0 8 0 amappl13 168 1159 0 1159 3 3 0 1 0 8 0 amappl12 160 617 0 614 2 1 1 1 0 8 0 amappl11 152 90 0 75 1 0 1 1 0 8 0 amappl10 144 112 0 106 1 0 1 1 0 8 0 amappl9 136 740 0 737 1 0 1 1 0 8 0 amappl8 128 255 0 233 1 0 1 1 0 8 0 amappl7 120 92 0 84 1 0 1 1 0 8 0 amappl6 112 97 0 88 1 0 1 1 0 8 0 amappl5 104 877 0 861 1 0 1 1 0 8 0 amappl4 96 3825 0 3793 2 1 1 2 0 8 0 amappl3 88 858 0 847 1 0 1 1 0 8 0 amappl2 80 26743 0 26663 3 1 2 3 0 8 0 amappl1 72 83998 0 83537 26 16 10 20 0 8 0 amappl 80 10477 0 10437 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 64 133 0 11 2 0 2 2 0 8 0 uaddrrnd 24 3398 0 3379 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3398 0 3379 1 0 1 1 0 8 0 vmmpekpl 168 29482 0 29450 3 0 3 3 0 8 0 vmmpepl 168 418625 0 416661 238 132 106 106 0 357 19 vmsppl 368 3395 0 3379 2 0 2 2 0 8 0 pdppl 4096 6803 0 6762 7 1 6 6 0 8 0 pvpl 32 880493 0 865726 291 148 143 171 0 265 7 pmappl 232 3397 0 3381 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 657 0 34 19 0 19 19 0 8 0