panic(ffffffff821cc112) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826314f8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff826314f8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get(ffffffff826314f8,1) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(1,1) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 m_getuio(ffff800020b02d88,0,44bc,ffff800020b02f08) at m_getuio+0xe4 sys/kern/uipc_socket.c:570 sosend(fffffd806e970a88,0,ffff800020b02f08,0,0,80) at sosend+0x54e sys/kern/uipc_socket.c:525 dofilewritev(ffff800020ad9648,4,ffff800020b02f08,0,ffff800020b02ff0) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ad9648,ffff800020b02fa0,ffff800020b02ff0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03070) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020b03070) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe5bd0, count: 4 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 pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806d646800+16 0x0!=0x801600a07f145ec6 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821cc112) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826314f8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff826314f8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get(ffffffff826314f8,1) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(1,1) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 m_getuio(ffff800020b02d88,0,44bc,ffff800020b02f08) at m_getuio+0xe4 sys/kern/uipc_socket.c:570 sosend(fffffd806e970a88,0,ffff800020b02f08,0,0,80) at sosend+0x54e sys/kern/uipc_socket.c:525 dofilewritev(ffff800020ad9648,4,ffff800020b02f08,0,ffff800020b02ff0) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ad9648,ffff800020b02fa0,ffff800020b02ff0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03070) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020b03070) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe5bd0, count: -11 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b02ab0 rbx 0xffff800020b02b60 rdx 0xffff800020ad9648 rcx 0 rax 0 r8 0xffffffff81d817ff kprintf+0x16f r9 0x1 r10 0x25 r11 0xa9e548273c5c71e7 r12 0x3000000008 r13 0xffff800020b02ac0 r14 0x100 r15 0x1 rip 0xffffffff81172258 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b02aa0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (sshd) pid=64147 stat=onproc flags process=12 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020ad8288,0xffff800020ad8c78 process=0xffff800020aa3c10 user=0xffff800020afe000, vmspace=0xfffffd806e7a2008 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 67994 385404 95079 0 2 0 syz-executor.0 67994 90062 95079 0 3 0x4000080 ttyout syz-executor.0 67809 35190 15854 0 7 0x2 syz-executor.1 95079 405457 15854 0 3 0x82 nanosleep syz-executor.0 15854 331206 75303 0 3 0x82 thrsleep syz-fuzzer 15854 285305 75303 0 3 0x4000082 nanosleep syz-fuzzer 15854 360249 75303 0 3 0x4000082 thrsleep syz-fuzzer 15854 415123 75303 0 3 0x4000082 nanosleep syz-fuzzer 15854 484403 75303 0 3 0x4000082 kqread syz-fuzzer 15854 47784 75303 0 3 0x4000082 thrsleep syz-fuzzer 15854 28277 75303 0 3 0x4000082 thrsleep syz-fuzzer 15854 51587 75303 0 3 0x4000082 thrsleep syz-fuzzer 15854 218979 75303 0 3 0x4000082 thrsleep syz-fuzzer 15854 245570 75303 0 3 0x4000082 thrsleep syz-fuzzer 15854 64247 75303 0 3 0x4000082 thrsleep syz-fuzzer 75303 423889 72430 0 3 0x10008a pause ksh *72430 64147 51239 0 7 0x12 sshd 19095 253100 1 0 3 0x100083 ttyin getty 51239 61715 1 0 3 0x80 select sshd 32514 193693 7330 74 3 0x100092 bpf pflogd 7330 298264 1 0 3 0x80 netio pflogd 38783 431029 10300 73 3 0x100090 kqread syslogd 10300 14607 1 0 3 0x100082 netio syslogd 17713 486651 1 77 3 0x100090 poll dhclient 53881 378876 1 0 3 0x80 poll dhclient 78135 164123 0 0 2 0x14200 zerothread 33478 476132 0 0 3 0x14200 aiodoned aiodoned 62901 154964 0 0 3 0x14200 syncer update 75063 401534 0 0 3 0x14200 cleaner cleaner 11593 57171 0 0 3 0x14200 reaper reaper 6696 22866 0 0 3 0x14200 pgdaemon pagedaemon 77792 462152 0 0 3 0x14200 bored crynlk 63362 294863 0 0 3 0x14200 bored crypto 99854 53162 0 0 3 0x40014200 acpi0 acpi0 94165 12563 0 0 3 0x40014200 idle1 99266 204209 0 0 3 0x14200 bored softnet 53765 141359 0 0 3 0x14200 bored systqmp 80675 315233 0 0 3 0x14200 bored systq 18811 203144 0 0 3 0x40014200 bored softclock 79939 354539 0 0 3 0x40014200 idle0 40640 56954 0 0 3 0x14200 bored smr 1 284396 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 67994 (syz-executor.0) thread 0xffff800020ad6c70 (385404) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8265d820) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 intr_handler+0x5e sys/arch/amd64/amd64/intr.c:525 #2 Xintr_ioapic_edge4_untramp+0x19f #3 Xspllower+0x19 #4 ast+0x107 mi_ast sys/sys/syscall_mi.h:164 [inline] #4 ast+0x107 sys/arch/amd64/amd64/trap.c:491 #5 Xsyscall+0x156 Process 67809 (syz-executor.1) thread 0xffff800020ad6508 (35190) exclusive rrwlock inode r = 0 (0xfffffd80630f8810) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 VOP_LOCK+0xf9 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #5 vget+0x1c8 sys/kern/vfs_subr.c:671 #6 ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1323 #8 ufs_lookup+0x14b7 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:91 #10 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568 #11 namei+0x63c sys/kern/vfs_lookup.c:249 #12 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1776 #13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806acc35e8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 VOP_LOCK+0xf9 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #5 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1776 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9490 6408K 6988K 78643K 10856 0 pcb 13 8K 8K 78643K 45 0 rtable 108 4K 4K 78643K 227 0 ifaddr 59 13K 13K 78643K 73 0 counters 39 33K 33K 78643K 39 0 ioctlops 0 0K 4K 78643K 1481 0 iov 0 0K 16K 78643K 21 0 mount 1 1K 1K 78643K 1 0 vnodes 1223 77K 77K 78643K 1301 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 5 0 VM map 2 1K 1K 78643K 2 0 sem 11 0K 1K 78643K 23 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 143 0 sigio 0 0K 0K 78643K 3 0 proc 61 63K 83K 78643K 451 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 22 0 in_multi 53 3K 3K 78643K 70 0 ether_multi 1 0K 0K 78643K 4 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 55 254K 254K 78643K 55 0 exec 0 0K 1K 78643K 224 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 120 54K 54K 78643K 1451 0 UVM aobj 15 4K 4K 78643K 17 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 30 0 NDP 8 0K 0K 78643K 14 0 temp 83 3002K 3066K 78643K 7650 0 kqueue 3 4K 8K 78643K 11 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 6 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 23 0 21 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 201 0 191 2 0 2 2 0 8 1 syncache 264 5 0 5 2 1 1 1 0 8 1 tcpqe 32 41 0 41 1 1 0 1 0 8 0 tcpcb 544 62 0 58 1 0 1 1 0 8 0 inpcb 280 305 0 298 2 0 2 2 0 8 1 nd6 48 4 0 0 1 0 1 1 0 8 0 pkpcb 40 67 0 67 1 0 1 1 0 8 1 ppxss 1128 2 0 2 1 0 1 1 0 8 1 pffrag 232 3 0 3 1 0 1 1 0 482 1 pffrnode 88 3 0 3 1 0 1 1 0 8 1 pffrent 40 93 0 93 1 0 1 1 0 8 1 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 1 1 0 1 1 0 8 0 pfstkey 112 31 0 1 1 0 1 1 0 8 0 pfstate 328 31 0 1 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 256 212 0 0 14 0 14 14 0 8 0 art_table 32 213 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 4 1 0 1 1 0 8 1 semupl 112 2 0 2 1 0 1 1 0 8 1 semapl 112 21 0 12 1 0 1 1 0 8 0 shmpl 112 15 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1617 0 205 46 0 46 46 0 8 0 ffsino 272 1617 0 205 95 0 95 95 0 8 0 nchpl 144 2032 0 415 61 0 61 61 0 8 0 uvmvnodes 72 1726 0 0 32 0 32 32 0 8 0 vnodes 208 1726 0 0 91 0 91 91 0 8 0 namei 1024 5527 0 5527 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 560 4 0 2 1 0 1 1 0 8 0 scxspl 192 5727 0 5727 7 1 6 6 0 8 6 plimitpl 152 26 0 18 1 0 1 1 0 8 0 sigapl 432 342 0 327 3 1 2 3 0 8 0 futexpl 56 2802 0 2802 1 0 1 1 0 8 1 knotepl 112 64 0 45 1 0 1 1 0 8 0 kqueuepl 104 58 0 56 1 0 1 1 0 8 0 pipelkpl 48 113 0 103 1 0 1 1 0 8 0 pipepl 120 226 0 207 2 0 2 2 0 8 1 fdescpl 496 343 0 327 3 0 3 3 0 8 0 filepl 152 2433 0 2332 7 1 6 6 0 8 2 lockfpl 104 53 0 52 1 0 1 1 0 8 0 lockfspl 48 16 0 15 1 0 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 22 0 11 1 0 1 1 0 8 0 ucredpl 96 209 0 199 1 0 1 1 0 8 0 zombiepl 144 327 0 327 2 1 1 1 0 8 1 processpl 896 358 0 327 4 0 4 4 0 8 0 procpl 632 662 0 620 5 0 5 5 0 8 1 sockpl 384 601 0 582 6 1 5 5 0 8 3 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 216 0 0 26 0 26 26 0 8 0 mtagpl 80 7 0 0 1 0 1 1 0 8 0 mbufpl 256 227 0 0 14 0 14 14 0 8 0 bufpl 280 6586 0 1342 375 0 375 375 0 8 0 anonpl 16 45577 0 30257 64 1 63 63 0 125 0 amapchunkpl 152 1661 0 1523 8 0 8 8 0 158 0 amappl16 192 1366 0 539 43 0 43 43 0 8 1 amappl15 184 58 0 55 1 0 1 1 0 8 0 amappl14 176 37 0 30 1 0 1 1 0 8 0 amappl13 168 9 0 8 2 1 1 1 0 8 0 amappl12 160 58 0 57 2 1 1 1 0 8 0 amappl11 152 62 0 46 1 0 1 1 0 8 0 amappl10 144 26 0 19 1 0 1 1 0 8 0 amappl9 136 659 0 654 1 0 1 1 0 8 0 amappl8 128 169 0 148 1 0 1 1 0 8 0 amappl7 120 99 0 90 1 0 1 1 0 8 0 amappl6 112 56 0 50 1 0 1 1 0 8 0 amappl5 104 190 0 175 1 0 1 1 0 8 0 amappl4 96 596 0 566 1 0 1 1 0 8 0 amappl3 88 117 0 109 1 0 1 1 0 8 0 amappl2 80 1840 0 1766 3 1 2 3 0 8 0 amappl1 72 17443 0 16994 25 15 10 20 0 8 0 amappl 80 921 0 873 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 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 64 16 0 2 1 0 1 1 0 8 0 uaddrrnd 24 347 0 329 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 347 0 329 1 0 1 1 0 8 0 vmmpekpl 168 6771 0 6740 2 0 2 2 0 8 0 vmmpepl 168 49466 0 47462 116 9 107 109 0 357 18 vmsppl 368 346 0 329 2 0 2 2 0 8 0 pdppl 4096 701 0 660 7 1 6 6 0 8 0 pvpl 32 156678 0 138173 158 1 157 157 0 265 5 pmappl 232 346 0 329 2 0 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 173 0 5 5 0 5 5 0 8 0