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 * 17940 8646 0 0 0x4000000 0 syz-executor.0 155926 64279 0 0x14000 0x200 1 reaper 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(ffff800022d80880) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007e04854,fffffd80662eff40) at alltraps_kern_meltdown+0x7b frag6_input(ffff800022d80be8,ffff800022d80bf4,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800022d80be8,ffff800022d80bf4,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800022d80be8,ffff800022d80bf4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800022d80be8,ffff800022d80bf4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806f207e00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806f207e00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806950a000,ffff800000ae3280,fffffd806f6ba2a0,0,0,fffffd806f6ba230) at ip6_output+0xd59 rip6_output(fffffd806950a000,fffffd807da36ac0,ffff800022d80f58,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff800022d80ff0, 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(ffff800022d80880) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007e04854,fffffd80662eff40) at alltraps_kern_meltdown+0x7b frag6_input(ffff800022d80be8,ffff800022d80bf4,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800022d80be8,ffff800022d80bf4,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800022d80be8,ffff800022d80bf4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800022d80be8,ffff800022d80bf4,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd806f207e00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd806f207e00,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806950a000,ffff800000ae3280,fffffd806f6ba2a0,0,0,fffffd806f6ba230) at ip6_output+0xd59 rip6_output(fffffd806950a000,fffffd807da36ac0,ffff800022d80f58,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd807da36ac0,9,fffffd806950a000,0,0,ffff800020abf650) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd807da36ac0,0,ffff800022d81188,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020abf650,3,ffff800022d81188,0,ffff800022d81290) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020abf650,ffff800022d81228,ffff800022d81290) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800022d81300) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800022d81300) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,669ab96010) at Xsyscall+0x128 end of kernel end trace frame: 0x699210f250, count: -20 ddb{0}> show registers rdi 0xffffffff81d56a37 db_enter+0x17 rsi 0x32aa __ALIGN_SIZE+0x22aa rbp 0xffff800022d805e0 rbx 0xffff800022d80690 rdx 0x32ab __ALIGN_SIZE+0x22ab rcx 0xffff800023992000 rax 0xffff800023992000 r8 0xffffffff812e94e3 kprintf+0x173 r9 0x1 r10 0x25 r11 0xa98f78079dd02cdc r12 0x3000000008 r13 0xffff800022d805f0 r14 0x100 r15 0x1 rip 0xffffffff81d56a38 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022d805d0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=17940 stat=onproc flags process=0 proc=4000000 pri=78, usrpri=78, nice=20 forw=0xffffffffffffffff, list=0xffff800020a5fb30,0xffffffff826641e8 process=0xffff800020a8ae10 user=0xffff800022d7c000, vmspace=0xfffffd807f00b8a0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 8646 500147 18797 0 2 0 syz-executor.0 * 8646 17940 18797 0 7 0x4000000 syz-executor.0 35757 473128 57266 0 3 0x82 nanosleep syz-executor.1 18797 293848 57266 0 3 0x82 nanosleep syz-executor.0 53605 360574 0 0 3 0x14200 acct acct 67358 167145 1 0 3 0x100083 ttyin getty 38110 16526 0 0 3 0x14200 bored sosplice 57266 104029 26801 0 3 0x82 thrsleep syz-fuzzer 57266 447410 26801 0 3 0x4000082 thrsleep syz-fuzzer 57266 149312 26801 0 3 0x4000082 thrsleep syz-fuzzer 57266 7437 26801 0 3 0x4000082 thrsleep syz-fuzzer 57266 118303 26801 0 3 0x4000082 thrsleep syz-fuzzer 57266 409163 26801 0 3 0x4000082 thrsleep syz-fuzzer 57266 378737 26801 0 3 0x4000082 kqread syz-fuzzer 57266 464345 26801 0 3 0x4000082 thrsleep syz-fuzzer 57266 311757 26801 0 3 0x4000082 thrsleep syz-fuzzer 57266 506147 26801 0 3 0x4000082 thrsleep syz-fuzzer 26801 211664 50832 0 3 0x10008a pause ksh 50832 362404 76027 0 3 0x92 select sshd 76027 377952 1 0 3 0x80 select sshd 41557 222693 63714 74 3 0x100092 bpf pflogd 63714 381154 1 0 3 0x80 netio pflogd 82185 19489 76030 73 3 0x100090 kqread syslogd 76030 244687 1 0 3 0x100082 netio syslogd 80233 83073 1 77 3 0x100090 poll dhclient 26573 483104 1 0 3 0x80 poll dhclient 60603 32186 0 0 2 0x14200 zerothread 33933 141048 0 0 3 0x14200 aiodoned aiodoned 39147 275314 0 0 3 0x14200 syncer update 75225 262655 0 0 3 0x14200 cleaner cleaner 64279 155926 0 0 7 0x14200 reaper 39715 412287 0 0 3 0x14200 pgdaemon pagedaemon 4292 388481 0 0 3 0x14200 bored crynlk 35867 203024 0 0 3 0x14200 bored crypto 21227 307580 0 0 3 0x40014200 acpi0 acpi0 9071 37829 0 0 3 0x40014200 idle1 28533 153064 0 0 3 0x14200 bored softnet 83711 323152 0 0 3 0x14200 bored systqmp 2476 491494 0 0 3 0x14200 bored systq 42541 287814 0 0 3 0x40014200 bored softclock 11940 4673 0 0 3 0x40014200 idle0 755 521478 0 0 3 0x14200 bored smr 1 364929 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 CPU 1: kernel: protection fault trap, code=0 Faulted in DDB; continuing... ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9590 6444K 7095K 78643K 20093 0 0 pcb 14 8K 8K 78643K 466 0 0 rtable 115 12K 13K 78643K 1265 0 0 ifaddr 81 17K 18K 78643K 475 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1679 0 0 iov 0 0K 16K 78643K 380 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1203 76K 77K 78643K 4635 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 60 0 0 VM map 2 1K 1K 78643K 11 0 0 sem 12 0K 0K 78643K 469 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 3829 0 0 sigio 0 0K 0K 78643K 48 0 0 proc 54 51K 71K 78643K 1120 0 0 subproc 32 2K 2K 78643K 191 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 311 0 0 in_multi 33 2K 2K 78643K 223 0 0 ether_multi 1 0K 0K 78643K 11 0 0 mrt 0 0K 0K 78643K 20 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 108 477K 477K 78643K 108 0 0 exec 0 0K 1K 78643K 674 0 0 pfkey data 0 0K 4K 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 105 22K 31K 78643K 13115 0 0 UVM aobj 130 4K 4K 78643K 155 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 486 0 0 NDP 19 0K 0K 78643K 140 0 0 temp 221 3556K 3646K 78643K 72920 0 0 kqueue 0 0K 0K 78643K 29 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 24 0 18 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 143 0 141 1 0 1 1 0 8 0 rtentry 112 157 0 113 2 0 2 2 0 8 0 unpcb 120 1242 0 1232 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 6488 0 6488 1 1 0 1 0 8 0 tcpcb 544 820 0 815 1 0 1 1 0 8 0 inpcb 280 2234 0 2226 4 3 1 2 0 8 0 rttmr 72 5 0 5 3 3 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 33 0 27 1 0 1 1 0 8 0 pkpcb 40 21 0 21 8 7 1 1 0 8 1 ppxss 1128 76 0 76 9 8 1 1 0 8 1 pffrag 232 9 0 9 5 5 0 1 0 482 0 pffrnode 88 9 0 9 5 5 0 1 0 8 0 pffrent 40 24 0 24 6 6 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 24 112 0 86 1 0 1 1 0 8 0 pfstkey 112 112 0 86 1 0 1 1 0 8 0 pfstate 328 112 0 86 3 0 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 256 658 0 464 15 2 13 14 0 8 0 art_table 32 659 0 464 2 0 2 2 0 8 0 art_node 16 148 0 108 1 0 1 1 0 8 0 sysvmsgpl 40 15 0 9 1 0 1 1 0 8 0 semapl 112 467 0 457 1 0 1 1 0 8 0 shmpl 112 153 0 25 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 7344 0 5929 47 0 47 47 0 8 0 ffsino 272 7344 0 5929 96 0 96 96 0 8 0 nchpl 144 12890 0 11256 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 41349 0 41349 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 552 9 0 9 4 4 0 1 0 8 0 scsiplug 64 7 0 7 4 4 0 1 0 8 0 scxspl 192 37611 0 37611 23 22 1 7 0 8 1 plimitpl 152 355 0 347 1 0 1 1 0 8 0 sigapl 432 4003 0 3988 3 1 2 3 0 8 0 futexpl 56 49018 0 49018 2 1 1 1 0 8 1 knotepl 112 750 0 731 1 0 1 1 0 8 0 kqueuepl 104 755 0 753 1 0 1 1 0 8 0 pipepl 112 2314 0 2295 6 4 2 2 0 8 1 fdescpl 488 4004 0 3988 3 0 3 3 0 8 0 filepl 152 23772 0 23672 13 8 5 7 0 8 1 lockfpl 104 997 0 997 3 2 1 1 0 8 1 lockfspl 48 354 0 354 3 2 1 1 0 8 1 sessionpl 112 28 0 17 1 0 1 1 0 8 0 pgrppl 48 60 0 49 1 0 1 1 0 8 0 ucredpl 96 4388 0 4379 1 0 1 1 0 8 0 zombiepl 144 3988 0 3987 2 1 1 1 0 8 0 processpl 896 4021 0 3987 4 0 4 4 0 8 0 procpl 632 11872 0 11828 9 4 5 5 0 8 1 srpgc 64 23 0 23 10 9 1 1 0 8 1 sosppl 128 44 0 44 13 13 0 1 0 8 0 sockpl 384 3675 0 3655 9 5 4 4 0 8 1 mcl64k 65536 19 0 0 3 0 3 3 0 8 0 mcl16k 16384 7 0 0 1 0 1 1 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 25 0 0 2 0 2 2 0 8 0 mcl8k 8192 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 184 0 0 21 3 18 21 0 8 0 mtagpl 80 52 0 0 1 0 1 1 0 8 0 mbufpl 256 346 0 0 12 0 12 12 0 8 0 bufpl 256 15692 0 8673 439 0 439 439 0 8 0 anonpl 16 359231 0 348726 129 70 59 69 0 124 4 amapchunkpl 152 23127 0 23012 28 19 9 10 0 158 3 amappl16 192 18757 0 18043 111 74 37 48 0 8 1 amappl15 184 1723 0 1723 1 0 1 1 0 8 1 amappl14 176 909 0 903 1 0 1 1 0 8 0 amappl13 168 237 0 237 4 4 0 1 0 8 0 amappl12 160 419 0 418 4 3 1 1 0 8 0 amappl11 152 169 0 153 1 0 1 1 0 8 0 amappl10 144 400 0 393 1 0 1 1 0 8 0 amappl9 136 1212 0 1208 1 0 1 1 0 8 0 amappl8 128 735 0 711 1 0 1 1 0 8 0 amappl7 120 388 0 381 1 0 1 1 0 8 0 amappl6 112 144 0 134 1 0 1 1 0 8 0 amappl5 104 634 0 620 1 0 1 1 0 8 0 amappl4 96 3737 0 3705 2 1 1 2 0 8 0 amappl3 88 1884 0 1874 1 0 1 1 0 8 0 amappl2 80 32025 0 31951 3 1 2 3 0 8 0 amappl1 72 94761 0 94323 26 15 11 20 0 8 0 amappl 80 12287 0 12247 2 1 1 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 64 154 0 25 3 0 3 3 0 8 0 uaddrrnd 24 4013 0 3988 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4013 0 3988 1 0 1 1 0 8 0 vmmpekpl 168 33114 0 33082 2 0 2 2 0 8 0 vmmpepl 168 490130 0 488277 248 141 107 107 0 357 21 vmsppl 368 4003 0 3988 2 0 2 2 0 8 0 pdppl 4096 8033 0 7994 7 1 6 6 0 8 0 pvpl 32 994865 0 981155 296 146 150 172 0 265 17 pmappl 232 4012 0 3997 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 613 0 11 18 0 18 18 0 8 0