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 261429 36984 0 0 0 1 syz-executor.0 *351047 36984 0 0 0x4000000 0 syz-executor.0 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(ffff800021b6a6e0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dfe054,fffffd8067edaf40) at alltraps_kern_meltdown+0x7b frag6_input(ffff800021b6aa48,ffff800021b6aa54,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800021b6aa48,ffff800021b6aa54,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800021b6aa48,ffff800021b6aa54,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800021b6aa48,ffff800021b6aa54,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd80695b1700) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd80695b1700,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806a658f00,ffff800000a9c080,fffffd806f6c6ea8,0,0,fffffd806f6c6e38) at ip6_output+0xd59 rip6_output(fffffd806a658f00,fffffd8068a541a8,ffff800021b6adb8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 end trace frame: 0xffff800021b6ae50, 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(ffff800021b6a6e0) at kerntrap+0xec sys/arch/amd64/amd64/trap.c:287 alltraps_kern_meltdown(6,0,600,0,fffffd8007dfe054,fffffd8067edaf40) at alltraps_kern_meltdown+0x7b frag6_input(ffff800021b6aa48,ffff800021b6aa54,2c,18) at frag6_input+0x7d2 sys/netinet6/frag6.c:321 ip_deliver(ffff800021b6aa48,ffff800021b6aa54,2c,18) at ip_deliver+0x353 sys/netinet/ip_input.c:665 ip6_input_if(ffff800021b6aa48,ffff800021b6aa54,29,0,ffff80000066d000) at ip6_input_if+0x17d4 ip6_ours sys/netinet6/ip6_input.c:518 [inline] ip6_input_if(ffff800021b6aa48,ffff800021b6aa54,29,0,ffff80000066d000) at ip6_input_if+0x17d4 sys/netinet6/ip6_input.c:340 ipv6_input(ffff80000066d000,fffffd80695b1700) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff80000066d000,fffffd80695b1700,18) at if_input_local+0x121 sys/net/if.c:783 ip6_output(fffffd806a658f00,ffff800000a9c080,fffffd806f6c6ea8,0,0,fffffd806f6c6e38) at ip6_output+0xd59 rip6_output(fffffd806a658f00,fffffd8068a541a8,ffff800021b6adb8,0) at rip6_output+0x4c0 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd8068a541a8,9,fffffd806a658f00,0,0,ffff800020abfb40) at rip6_usrreq+0x5cd sys/netinet6/raw_ip6.c:670 sosend(fffffd8068a541a8,0,ffff800021b6afe8,0,0,0) at sosend+0x668 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020abfb40,4,ffff800021b6afe8,0,ffff800021b6b0f0) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020abfb40,ffff800021b6b088,ffff800021b6b0f0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800021b6b160) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800021b6b160) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,c,0,3,cf061ee5010) at Xsyscall+0x128 end of kernel end trace frame: 0xcf2f5b3cca0, count: -20 ddb{0}> show registers rdi 0xffffffff81d56a37 db_enter+0x17 rsi 0x2f77 __ALIGN_SIZE+0x1f77 rbp 0xffff800021b6a440 rbx 0xffff800021b6a4f0 rdx 0x2f78 __ALIGN_SIZE+0x1f78 rcx 0xffff800023b88000 rax 0xffff800023b88000 r8 0xffffffff812e94e3 kprintf+0x173 r9 0x1 r10 0x25 r11 0x88cfc1be01a4974b r12 0x3000000008 r13 0xffff800021b6a450 r14 0x100 r15 0x1 rip 0xffffffff81d56a38 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021b6a430 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=351047 stat=onproc flags process=0 proc=4000000 pri=81, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff800020abeee8,0xffffffff826641e8 process=0xffff800020add180 user=0xffff800021b66000, vmspace=0xfffffd807f00b730 estcpu=31, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 36984 261429 72591 0 7 0 syz-executor.0 *36984 351047 72591 0 7 0x4000000 syz-executor.0 55736 520526 85358 0 3 0x82 nanosleep syz-executor.1 72591 197810 85358 0 3 0x82 nanosleep syz-executor.0 57629 203421 1 0 3 0x100083 ttyin getty 94021 469523 0 0 3 0x14200 bored sosplice 85358 40231 44266 0 3 0x82 thrsleep syz-fuzzer 85358 123599 44266 0 3 0x4000082 nanosleep syz-fuzzer 85358 435397 44266 0 3 0x4000082 thrsleep syz-fuzzer 85358 122007 44266 0 3 0x4000082 kqread syz-fuzzer 85358 265886 44266 0 3 0x4000082 thrsleep syz-fuzzer 85358 270631 44266 0 3 0x4000082 thrsleep syz-fuzzer 85358 147938 44266 0 3 0x4000082 thrsleep syz-fuzzer 85358 263004 44266 0 3 0x4000082 thrsleep syz-fuzzer 85358 264055 44266 0 3 0x4000082 thrsleep syz-fuzzer 85358 8349 44266 0 3 0x4000082 thrsleep syz-fuzzer 44266 342763 87959 0 3 0x10008a pause ksh 87959 249982 17529 0 3 0x92 select sshd 17529 353678 1 0 3 0x80 select sshd 53640 238261 38628 74 3 0x100092 bpf pflogd 38628 251052 1 0 3 0x80 netio pflogd 80714 394119 20955 73 3 0x100090 kqread syslogd 20955 128527 1 0 3 0x100082 netio syslogd 51009 372509 1 77 3 0x100090 poll dhclient 29511 92063 1 0 3 0x80 poll dhclient 22386 91382 0 0 3 0x14200 pgzero zerothread 80333 38877 0 0 3 0x14200 aiodoned aiodoned 30658 197536 0 0 3 0x14200 syncer update 93038 143689 0 0 3 0x14200 cleaner cleaner 59592 195368 0 0 3 0x14200 reaper reaper 44439 81818 0 0 3 0x14200 pgdaemon pagedaemon 80320 455737 0 0 3 0x14200 bored crynlk 21334 361878 0 0 3 0x14200 bored crypto 83450 423140 0 0 3 0x40014200 acpi0 acpi0 51375 369720 0 0 3 0x40014200 idle1 33330 160378 0 0 3 0x14200 bored softnet 17202 63474 0 0 3 0x14200 bored systqmp 31269 58007 0 0 3 0x14200 bored systq 97196 144256 0 0 3 0x40014200 bored softclock 53735 390607 0 0 3 0x40014200 idle0 80550 156244 0 0 3 0x14200 bored smr 1 337202 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 36984 (syz-executor.0) thread 0xffff800020abfb40 (351047) 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 9563 6696K 7075K 78643K 15604 0 0 pcb 14 8K 8K 78643K 591 0 0 rtable 115 12K 13K 78643K 797 0 0 ifaddr 70 16K 16K 78643K 278 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1573 0 0 iov 0 0K 16K 78643K 144 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1216 76K 77K 78643K 2966 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 21 0 0 VM map 2 1K 1K 78643K 7 0 0 sem 12 0K 0K 78643K 180 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 2392 0 0 sigio 0 0K 0K 78643K 32 0 0 proc 54 51K 83K 78643K 826 0 0 subproc 32 2K 2K 78643K 119 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 178 0 0 in_multi 33 2K 2K 78643K 158 0 0 ether_multi 1 0K 0K 78643K 8 0 0 mrt 0 0K 0K 78643K 7 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 404 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 99 21K 25K 78643K 8189 0 0 UVM aobj 63 3K 3K 78643K 70 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 847 0 0 NDP 15 0K 0K 78643K 82 0 0 temp 195 3556K 3624K 78643K 30999 0 0 kqueue 0 0K 0K 78643K 10 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 16 0 10 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 110 0 108 1 0 1 1 0 8 0 rtentry 112 106 0 62 2 0 2 2 0 8 0 unpcb 120 542 0 532 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 9837 0 9837 2 2 0 2 0 8 0 tcpcb 544 943 0 938 1 0 1 1 0 8 0 inpcb 280 2670 0 2662 2 1 1 2 0 8 0 rttmr 72 2 0 2 1 1 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 21 0 15 1 0 1 1 0 8 0 pkpcb 40 16 0 16 5 5 0 1 0 8 0 ppxss 1128 39 0 38 5 4 1 1 0 8 0 pffrag 232 3 0 3 2 2 0 1 0 482 0 pffrnode 88 3 0 3 2 2 0 1 0 8 0 pffrent 40 8 0 8 2 2 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 89 0 61 1 0 1 1 0 8 0 pfstkey 112 89 0 61 1 0 1 1 0 8 0 pfstate 328 89 0 61 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 256 457 0 262 15 2 13 14 0 8 0 art_table 32 458 0 262 2 0 2 2 0 8 0 art_node 16 101 0 61 1 0 1 1 0 8 0 sysvmsgpl 40 14 0 8 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 176 0 166 1 0 1 1 0 8 0 shmpl 112 68 0 7 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4851 0 3425 47 0 47 47 0 8 0 ffsino 272 4851 0 3425 96 0 96 96 0 8 0 nchpl 144 8216 0 6582 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 24907 0 24907 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 552 5 0 5 2 2 0 1 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 23078 0 23078 17 14 3 7 0 8 3 plimitpl 152 201 0 193 1 0 1 1 0 8 0 sigapl 432 2579 0 2564 3 1 2 3 0 8 0 futexpl 56 31429 0 31429 1 0 1 1 0 8 1 knotepl 112 467 0 448 1 0 1 1 0 8 0 kqueuepl 104 396 0 394 1 0 1 1 0 8 0 pipepl 112 1292 0 1273 2 1 1 2 0 8 0 fdescpl 488 2580 0 2564 3 0 3 3 0 8 0 filepl 152 14600 0 14499 7 2 5 6 0 8 1 lockfpl 104 663 0 663 3 2 1 1 0 8 1 lockfspl 48 221 0 221 3 2 1 1 0 8 1 sessionpl 112 25 0 14 1 0 1 1 0 8 0 pgrppl 48 59 0 48 1 0 1 1 0 8 0 ucredpl 96 2244 0 2234 1 0 1 1 0 8 0 zombiepl 144 2564 0 2563 3 2 1 1 0 8 0 processpl 896 2596 0 2563 4 0 4 4 0 8 0 procpl 632 7166 0 7123 12 7 5 5 0 8 1 srpgc 64 12 0 12 5 4 1 1 0 8 1 sosppl 128 24 0 24 7 6 1 1 0 8 1 sockpl 384 3358 0 3338 6 3 3 4 0 8 0 mcl64k 65536 258 0 0 33 4 29 33 0 8 1 mcl16k 16384 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 10 0 0 1 0 1 1 0 8 0 mcl8k 8192 11 0 0 2 0 2 2 0 8 0 mcl4k 4096 10 0 0 2 0 2 2 0 8 0 mcl2k2 2112 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 203 0 0 25 2 23 25 0 8 0 mtagpl 80 37 0 0 1 0 1 1 0 8 0 mbufpl 256 451 0 0 23 0 23 23 0 8 0 bufpl 256 11000 0 3981 439 0 439 439 0 8 0 anonpl 16 222133 0 211089 92 24 68 68 0 124 12 amapchunkpl 152 13856 0 13748 19 12 7 10 0 158 1 amappl16 192 11843 0 11083 68 21 47 51 0 8 8 amappl15 184 621 0 620 1 0 1 1 0 8 0 amappl14 176 87 0 81 1 0 1 1 0 8 0 amappl13 168 447 0 447 3 3 0 1 0 8 0 amappl12 160 514 0 513 2 1 1 1 0 8 0 amappl11 152 343 0 325 1 0 1 1 0 8 0 amappl10 144 551 0 547 1 0 1 1 0 8 0 amappl9 136 671 0 667 1 0 1 1 0 8 0 amappl8 128 195 0 174 1 0 1 1 0 8 0 amappl7 120 531 0 523 1 0 1 1 0 8 0 amappl6 112 317 0 309 1 0 1 1 0 8 0 amappl5 104 682 0 668 1 0 1 1 0 8 0 amappl4 96 2637 0 2607 2 1 1 2 0 8 0 amappl3 88 752 0 742 1 0 1 1 0 8 0 amappl2 80 20167 0 20092 3 1 2 3 0 8 0 amappl1 72 63305 0 62869 26 16 10 20 0 8 0 amappl 80 7503 0 7465 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 69 0 7 1 0 1 1 0 8 0 uaddrrnd 24 2585 0 2564 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2585 0 2564 1 0 1 1 0 8 0 vmmpekpl 168 22414 0 22383 2 0 2 2 0 8 0 vmmpepl 168 314292 0 312406 197 87 110 110 0 357 23 vmsppl 368 2579 0 2564 2 0 2 2 0 8 0 pdppl 4096 5177 0 5138 7 1 6 6 0 8 0 pvpl 32 636641 0 622406 223 56 167 167 0 265 28 pmappl 232 2584 0 2569 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 657 0 14 19 0 19 19 0 8 0