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 *476821 60823 0 0 0x4000000 1 syz-executor.1 99432 13345 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(ffffffff82672640,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff82672438) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800020a873f0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd80690e0054,fffffd8062b8ef08) at alltraps_kern_meltdown+0x7b frag6_input(ffff800020a87758,ffff800020a87764,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800020a87758,ffff800020a87764,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800020a87758,ffff800020a87764,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800020a87758,ffff800020a87764,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806f09ed00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806f09ed00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd8065dd8000,ffff800000a98e00,fffffd806f6bb5e8,0,0,fffffd806f6bb578) at ip6_output+0xd59 rip6_output(fffffd8065dd8000,fffffd8075fa1180,ffff800020a87ac8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff800020a87b60, 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(ffffffff82672640,9,0) at witness_checkorder+0x10cc sys/kern/subr_witness.c:820 __mp_lock(ffffffff82672438) at __mp_lock+0xa1 pageflttrap() at pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 kerntrap(ffff800020a873f0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd80690e0054,fffffd8062b8ef08) at alltraps_kern_meltdown+0x7b frag6_input(ffff800020a87758,ffff800020a87764,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800020a87758,ffff800020a87764,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800020a87758,ffff800020a87764,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800020a87758,ffff800020a87764,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806f09ed00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806f09ed00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd8065dd8000,ffff800000a98e00,fffffd806f6bb5e8,0,0,fffffd806f6bb578) at ip6_output+0xd59 rip6_output(fffffd8065dd8000,fffffd8075fa1180,ffff800020a87ac8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd8075fa1180,9,fffffd8065dd8000,0,0,ffff800020ab1920) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd8075fa1180,0,ffff800020a87cf8,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ab1920,5,ffff800020a87cf8,0,ffff800020a87e00) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020ab1920,ffff800020a87d98,ffff800020a87e00) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020a87e70) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020a87e70) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,794d749010) at Xsyscall+0x128 end of kernel end trace frame: 0x7bf8031850, count: -20 ddb{1}> show registers rdi 0xffffffff81be0707 db_enter+0x17 rsi 0x2acf __ALIGN_SIZE+0x1acf rbp 0xffff800020a87150 rbx 0xffff800020a87200 rdx 0x2ad0 __ALIGN_SIZE+0x1ad0 rcx 0xffff800021150000 rax 0xffff800021150000 r8 0xffffffff81da97e3 kprintf+0x173 r9 0x1 r10 0x25 r11 0xe315a664c0343aa2 r12 0x3000000008 r13 0xffff800020a87160 r14 0x100 r15 0x1 rip 0xffffffff81be0708 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a87140 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=476821 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020ab0a50,0xffffffff82655a00 process=0xffff800020a8aa90 user=0xffff800020a82000, vmspace=0xfffffd807f00ccf0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 60823 497261 93248 0 2 0 syz-executor.1 *60823 476821 93248 0 7 0x4000000 syz-executor.1 72752 261030 73271 0 2 0x482 syz-executor.0 93248 166551 73271 0 3 0x82 nanosleep syz-executor.1 24576 223498 0 0 3 0x14200 acct acct 71458 61809 1 0 3 0x100083 ttyin getty 10560 452344 0 0 3 0x14200 bored sosplice 73271 66701 4339 0 3 0x82 thrsleep syz-fuzzer 73271 487552 4339 0 3 0x4000082 nanosleep syz-fuzzer 73271 522162 4339 0 3 0x4000082 thrsleep syz-fuzzer 73271 348569 4339 0 3 0x4000082 kqread syz-fuzzer 73271 446803 4339 0 3 0x4000082 thrsleep syz-fuzzer 73271 214136 4339 0 3 0x4000082 thrsleep syz-fuzzer 73271 44984 4339 0 3 0x4000082 thrsleep syz-fuzzer 73271 24147 4339 0 3 0x4000082 thrsleep syz-fuzzer 73271 149506 4339 0 3 0x4000082 thrsleep syz-fuzzer 73271 518319 4339 0 3 0x4000082 thrsleep syz-fuzzer 4339 502846 17862 0 3 0x10008a pause ksh 17862 440368 46414 0 3 0x92 select sshd 46414 335069 1 0 3 0x80 select sshd 87025 392576 88277 74 3 0x100092 bpf pflogd 88277 328787 1 0 3 0x80 netio pflogd 33271 446763 33244 73 3 0x100090 kqread syslogd 33244 491724 1 0 3 0x100082 netio syslogd 84668 457889 1 77 3 0x100090 poll dhclient 90533 416093 1 0 3 0x80 poll dhclient 71417 279580 0 0 3 0x14200 pgzero zerothread 81236 361986 0 0 3 0x14200 aiodoned aiodoned 6575 90123 0 0 3 0x14200 syncer update 70037 418009 0 0 3 0x14200 cleaner cleaner 79086 473389 0 0 3 0x14200 reaper reaper 90285 134531 0 0 3 0x14200 pgdaemon pagedaemon 31170 394176 0 0 3 0x14200 bored crynlk 70052 430896 0 0 3 0x14200 bored crypto 26968 420012 0 0 3 0x40014200 acpi0 acpi0 27447 24593 0 0 3 0x40014200 idle1 32666 260328 0 0 3 0x14200 bored softnet 23986 116579 0 0 3 0x14200 bored systqmp 37677 443027 0 0 3 0x14200 bored systq 13345 99432 0 0 7 0x40014200 softclock 2934 391485 0 0 3 0x40014200 idle0 26142 294382 0 0 3 0x14200 bored smr 1 376611 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 (0xffffffff82484090) #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 60823 (syz-executor.1) thread 0xffff800020ab1920 (476821) exclusive rwlock netlock r = 0 (0xffffffff824be8a8) #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 (0xffffffff82484090) #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 9664 6500K 15400K 78643K 104749 0 0 pcb 14 8K 8K 78643K 3921 0 0 rtable 119 13K 13K 78643K 11768 0 0 ifaddr 99 37K 49K 78643K 4236 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 3345 0 0 iov 0 0K 32K 78643K 3669 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1199 75K 77K 78643K 34941 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 503 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 4292 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 37320 0 0 sigio 0 0K 0K 78643K 484 0 0 proc 55 51K 83K 78643K 8552 0 0 subproc 32 2K 2K 78643K 2034 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 3215 0 0 in_multi 33 2K 2K 78643K 2436 0 0 ether_multi 1 0K 0K 78643K 190 0 0 mrt 4 0K 0K 78643K 122 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 162 715K 715K 78643K 162 0 0 exec 0 0K 1K 78643K 4905 0 0 pfkey data 0 0K 4K 78643K 6 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 122 23K 33K 78643K 120562 0 0 UVM aobj 130 4K 4K 78643K 156 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 4268 0 0 NDP 25 0K 1K 78643K 1309 0 0 temp 263 3557K 4197K 78643K 511316 0 0 kqueue 0 0K 0K 78643K 262 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 64 256 0 250 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 1492 0 1490 1 0 1 1 0 8 0 rtentry 112 1396 0 1352 3 1 2 2 0 8 0 unpcb 120 11859 0 11849 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 8774 0 8774 2 2 0 1 0 8 0 tcpcb 544 7322 0 7317 1 0 1 1 0 8 0 inpcb 280 21192 0 21181 64 62 2 2 0 8 1 rttmr 72 19 0 19 17 17 0 1 0 8 0 ip6q 72 8 0 7 7 6 1 1 0 8 0 ip6af 48 8 0 7 6 5 1 1 0 8 0 nd6 48 354 0 348 1 0 1 1 0 8 0 pkpcb 40 163 0 163 59 59 0 1 0 8 0 swfcl 56 14 0 0 1 0 1 1 0 8 0 ppxss 1128 767 0 767 74 73 1 1 0 8 1 pffrag 232 50 0 50 30 30 0 1 0 482 0 pffrnode 88 50 0 50 30 30 0 1 0 8 0 pffrent 40 126 0 126 32 32 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 24 963 0 940 1 0 1 1 0 8 0 pfstkey 112 965 0 942 4 2 2 2 0 8 0 pfstate 328 965 0 942 11 8 3 4 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 5732 0 5534 25 12 13 14 0 8 0 art_table 32 5733 0 5534 2 0 2 2 0 8 0 art_node 16 1357 0 1317 1 0 1 1 0 8 0 sysvmsgpl 40 17 0 7 1 0 1 1 0 8 0 semapl 112 4288 0 4278 1 0 1 1 0 8 0 shmpl 112 154 0 26 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 58439 0 56890 52 1 51 51 0 8 0 ffsino 272 58439 0 56890 107 3 104 104 0 8 0 nchpl 144 110098 0 108459 62 0 62 62 0 8 0 uvmvnodes 72 9619 0 0 175 0 175 175 0 8 0 vnodes 200 9619 0 0 507 0 507 507 0 8 0 namei 1024 364696 0 364696 11 10 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 83 0 83 47 47 0 1 0 8 0 scxspl 192 324164 0 324164 158 156 2 7 0 8 2 plimitpl 152 3435 0 3427 1 0 1 1 0 8 0 sigapl 432 37175 0 37160 3 1 2 3 0 8 0 futexpl 56 486453 0 486453 8 7 1 1 0 8 1 knotepl 112 7862 0 7843 1 0 1 1 0 8 0 kqueuepl 104 7623 0 7621 1 0 1 1 0 8 0 pipepl 112 20866 0 20845 36 35 1 2 0 8 0 fdescpl 488 37176 0 37160 3 0 3 3 0 8 0 filepl 152 220609 0 220505 57 52 5 7 0 8 0 lockfpl 104 11556 0 11556 14 13 1 1 0 8 1 lockfspl 48 3902 0 3902 14 13 1 1 0 8 1 sessionpl 112 137 0 126 1 0 1 1 0 8 0 pgrppl 48 489 0 478 1 0 1 1 0 8 0 ucredpl 96 41251 0 41238 1 0 1 1 0 8 0 zombiepl 144 37172 0 37171 10 9 1 1 0 8 0 processpl 896 37205 0 37171 4 0 4 4 0 8 0 procpl 632 113963 0 113919 15 10 5 5 0 8 0 srpgc 64 251 0 251 99 98 1 1 0 8 1 sosppl 128 440 0 440 91 91 0 1 0 8 0 sockpl 384 35094 0 35074 39 36 3 4 0 8 0 mcl64k 65536 2225 0 0 229 168 61 66 0 8 0 mcl16k 16384 57 0 0 7 4 3 3 0 8 0 mcl12k 12288 97 0 0 2 0 2 2 0 8 0 mcl9k 9216 103 0 0 5 3 2 2 0 8 0 mcl8k 8192 42 0 0 6 3 3 3 0 8 1 mcl4k 4096 49 0 0 5 2 3 3 0 8 0 mcl2k2 2112 33 0 0 2 0 2 2 0 8 0 mcl2k 2048 284 0 0 22 15 7 22 0 8 0 mtagpl 80 226 0 0 2 0 2 2 0 8 0 mbufpl 256 2592 0 0 42 6 36 38 0 8 0 bufpl 256 92117 0 82498 602 0 602 602 0 8 0 anonpl 16 3269038 0 3258042 635 567 68 85 0 124 9 amapchunkpl 152 220027 0 219910 163 154 9 19 0 158 3 amappl16 192 184922 0 184212 824 780 44 56 0 8 7 amappl15 184 3214 0 3213 12 11 1 1 0 8 0 amappl14 176 3191 0 3183 1 0 1 1 0 8 0 amappl13 168 11380 0 11379 1 0 1 1 0 8 0 amappl12 160 5772 0 5771 4 3 1 1 0 8 0 amappl11 152 3407 0 3390 1 0 1 1 0 8 0 amappl10 144 4694 0 4687 1 0 1 1 0 8 0 amappl9 136 6491 0 6488 1 0 1 1 0 8 0 amappl8 128 5595 0 5553 2 0 2 2 0 8 0 amappl7 120 4748 0 4738 1 0 1 1 0 8 0 amappl6 112 3108 0 3097 1 0 1 1 0 8 0 amappl5 104 6874 0 6860 1 0 1 1 0 8 0 amappl4 96 39335 0 39304 2 1 1 2 0 8 0 amappl3 88 5780 0 5770 1 0 1 1 0 8 0 amappl2 80 294915 0 294842 4 1 3 3 0 8 0 amappl1 72 806350 0 805916 26 16 10 20 0 8 0 amappl 80 116210 0 116169 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 64 155 0 26 3 0 3 3 0 8 0 uaddrrnd 24 37176 0 37160 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 37176 0 37160 1 0 1 1 0 8 0 vmmpekpl 168 268085 0 268052 2 0 2 2 0 8 0 vmmpepl 168 4503917 0 4502054 1278 1165 113 114 0 357 24 vmsppl 368 37175 0 37160 2 0 2 2 0 8 0 pdppl 4096 74359 0 74320 7 1 6 6 0 8 0 pvpl 32 8685318 0 8671054 1324 1157 167 183 0 265 28 pmappl 232 37175 0 37160 8 6 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 1074 0 227 25 0 25 25 0 8 0