panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd80669f5f00+16 0x0!=0xa4026219b98aa89d Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 463986 15049 0 0 0 0 syz-executor.1 *374842 15049 0 0 0x4000000 1 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 pool_cache_get(ffffffff8262f140) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff8262f140) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd80643f8000,3854,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd80643f8000,3854,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd80643f8000,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd80643f8000,0,fffffd806f6ce700,20,0,fffffd806f6ce690) at ip_output+0xfc1 sys/netinet/ip_output.c:501 rip_output(fffffd80643f8000,fffffd807d466310,ffff800023da75d8,ffff800021b82000) at rip_output+0x252 sys/netinet/raw_ip.c:289 rip_usrreq(fffffd807d466310,9,fffffd80643f8000,0,0,ffff800020ab0290) at rip_usrreq+0x46a sys/netinet/raw_ip.c:538 sosend(fffffd807d466310,0,ffff800023da7740,0,0,80) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020ab0290,8,ffff800023da7820,0,ffff800023da7900) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020ab0290,ffff800023da78b8,ffff800023da7900) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800023da7980) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023da7980) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,ffffffffffffffd7,0,6,f8108741010) at Xsyscall+0x128 end of kernel end trace frame: 0xf84076f60f0, count: 1 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 0xfffffd80669f5f00+16 0x0!=0xa4026219b98aa89d 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 pool_cache_get(ffffffff8262f140) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff8262f140) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd80643f8000,3854,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd80643f8000,3854,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd80643f8000,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd80643f8000,0,fffffd806f6ce700,20,0,fffffd806f6ce690) at ip_output+0xfc1 sys/netinet/ip_output.c:501 rip_output(fffffd80643f8000,fffffd807d466310,ffff800023da75d8,ffff800021b82000) at rip_output+0x252 sys/netinet/raw_ip.c:289 rip_usrreq(fffffd807d466310,9,fffffd80643f8000,0,0,ffff800020ab0290) at rip_usrreq+0x46a sys/netinet/raw_ip.c:538 sosend(fffffd807d466310,0,ffff800023da7740,0,0,80) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020ab0290,8,ffff800023da7820,0,ffff800023da7900) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020ab0290,ffff800023da78b8,ffff800023da7900) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800023da7980) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023da7980) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,ffffffffffffffd7,0,6,f8108741010) at Xsyscall+0x128 end of kernel end trace frame: 0xf84076f60f0, count: -14 ddb{1}> show registers rdi 0xffffffff8101a1f7 db_enter+0x17 rsi 0x6771 __ALIGN_SIZE+0x5771 rbp 0xffff800023da7100 rbx 0xffff800023da71b0 rdx 0x6772 __ALIGN_SIZE+0x5772 rcx 0xffff800021b82000 rax 0xffff800021b82000 r8 0xffffffff812be63f kprintf+0x16f r9 0x1 r10 0x25 r11 0xea1d3d2ab5562c6d r12 0x3000000008 r13 0xffff800023da7110 r14 0x100 r15 0x1 rip 0xffffffff8101a1f8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800023da70f0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=374842 stat=onproc flags process=0 proc=4000000 pri=52, usrpri=52, nice=20 forw=0xffffffffffffffff, list=0xffff800020ab1b40,0xffffffff8262b978 process=0xffff800020adca80 user=0xffff800023da2000, vmspace=0xfffffd807f00bb80 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 15049 463986 53389 0 7 0 syz-executor.1 *15049 374842 53389 0 7 0x4000000 syz-executor.1 53389 337125 28215 0 3 0x82 nanosleep syz-executor.1 16859 3470 0 0 3 0x14200 acct acct 79631 123923 0 0 3 0x14200 bored sosplice 30494 64431 28215 0 3 0x82 piperd syz-executor.0 28215 201486 78789 0 3 0x82 thrsleep syz-fuzzer 28215 486808 78789 0 2 0x4000482 syz-fuzzer 28215 225952 78789 0 3 0x4000082 thrsleep syz-fuzzer 28215 357771 78789 0 3 0x4000082 thrsleep syz-fuzzer 28215 377116 78789 0 3 0x4000082 thrsleep syz-fuzzer 28215 51469 78789 0 3 0x4000082 thrsleep syz-fuzzer 28215 209238 78789 0 3 0x4000082 thrsleep syz-fuzzer 28215 143821 78789 0 3 0x4000082 thrsleep syz-fuzzer 28215 303512 78789 0 3 0x4000082 kqread syz-fuzzer 28215 437516 78789 0 2 0x4000482 syz-fuzzer 78789 242396 24297 0 3 0x10008a pause ksh 24297 337413 43325 0 3 0x92 select sshd 52528 188890 1 0 3 0x100083 ttyin getty 43325 96757 1 0 3 0x80 select sshd 91504 50745 11930 74 3 0x100092 bpf pflogd 11930 119419 1 0 3 0x80 netio pflogd 47504 360066 52604 73 3 0x100090 kqread syslogd 52604 344023 1 0 3 0x100082 netio syslogd 55658 101316 1 77 3 0x100090 poll dhclient 61901 232198 1 0 3 0x80 poll dhclient 79125 283254 0 0 2 0x14200 zerothread 76796 56801 0 0 3 0x14200 aiodoned aiodoned 74487 502896 0 0 3 0x14200 syncer update 78902 331459 0 0 3 0x14200 cleaner cleaner 82157 69242 0 0 3 0x14200 reaper reaper 73616 296459 0 0 3 0x14200 pgdaemon pagedaemon 99402 335029 0 0 3 0x14200 bored crynlk 82270 257647 0 0 3 0x14200 bored crypto 3831 497493 0 0 3 0x40014200 acpi0 acpi0 34274 501586 0 0 3 0x40014200 idle1 18787 374275 0 0 3 0x14200 bored softnet 20022 190952 0 0 3 0x14200 bored systqmp 5013 423070 0 0 3 0x14200 bored systq 65757 270905 0 0 3 0x40014200 bored softclock 34674 181084 0 0 3 0x40014200 idle0 21032 150738 0 0 3 0x14200 bored smr 1 439521 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 15049 (syz-executor.1) thread 0xffff800020ab0290 (374842) exclusive rwlock netlock r = 0 (0xffffffff824b9ff8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x51b sys/kern/uipc_socket.c:512 #3 sendit+0x52b sys/kern/uipc_syscalls.c:662 #4 sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 #5 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #5 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #6 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9511 6411K 7632K 78643K 12430 0 0 pcb 13 8K 8K 78643K 81 0 0 rtable 108 4K 4K 78643K 398 0 0 ifaddr 58 13K 13K 78643K 110 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1497 0 0 iov 0 0K 32K 78643K 80 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1229 77K 78K 78643K 1749 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 5 0 0 VM map 6 3K 3K 78643K 10 0 0 sem 12 0K 0K 78643K 164 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 368 0 0 sigio 0 0K 0K 78643K 5 0 0 proc 61 63K 95K 78643K 548 0 0 subproc 32 2K 2K 78643K 68 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 34 0 0 in_multi 34 2K 2K 78643K 64 0 0 ether_multi 1 0K 0K 78643K 4 0 0 mrt 0 0K 0K 78643K 3 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 54 238K 238K 78643K 54 0 0 exec 0 0K 1K 78643K 276 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 108 55K 55K 78643K 2235 0 0 UVM aobj 84 3K 3K 78643K 84 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 47 0 0 NDP 13 0K 0K 78643K 31 0 0 temp 164 3555K 3624K 78643K 14098 0 0 kqueue 0 0K 0K 78643K 2 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 13 0 7 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 39 0 37 1 0 1 1 0 8 0 rtentry 112 77 0 33 2 0 2 2 0 8 0 unpcb 120 177 0 164 1 0 1 1 0 8 0 syncache 264 6 0 6 2 1 1 1 0 8 1 tcpcb 544 365 0 360 1 0 1 1 0 8 0 inpcb 280 665 0 656 3 1 2 3 0 8 1 rttmr 72 1 0 1 1 1 0 1 0 8 0 nd6 48 8 0 4 1 0 1 1 0 8 0 ppxss 1128 7 0 7 3 2 1 1 0 8 1 pffrag 232 8 0 8 3 2 1 1 0 482 1 pffrnode 88 8 0 8 3 2 1 1 0 8 1 pffrent 40 185 0 185 3 2 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 41 0 5 1 0 1 1 0 8 0 pfstkey 112 41 0 5 2 0 2 2 0 8 0 pfstate 328 41 0 5 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 256 315 0 95 14 0 14 14 0 8 0 art_table 32 316 0 95 2 0 2 2 0 8 0 art_node 16 74 0 34 1 0 1 1 0 8 0 sysvmsgpl 40 47 0 26 1 0 1 1 0 8 0 semupl 112 4 0 4 1 1 0 1 0 8 0 semapl 112 160 0 150 1 0 1 1 0 8 0 shmpl 112 82 0 0 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1920 0 514 46 0 46 46 0 8 0 ffsino 272 1920 0 514 94 0 94 94 0 8 0 nchpl 144 2657 0 1051 61 0 61 61 0 8 0 uvmvnodes 72 2413 0 0 44 0 44 44 0 8 0 vnodes 208 2413 0 0 127 0 127 127 0 8 0 namei 1024 8082 0 8082 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 4 0 0 1 0 1 1 0 8 0 vmpool 552 8 0 4 1 0 1 1 0 8 0 scxspl 192 7734 0 7734 8 7 1 7 0 8 1 plimitpl 152 51 0 43 1 0 1 1 0 8 0 sigapl 432 562 0 547 3 1 2 3 0 8 0 futexpl 56 8180 0 8180 1 0 1 1 0 8 1 knotepl 112 133 0 114 1 0 1 1 0 8 0 kqueuepl 104 84 0 82 1 0 1 1 0 8 0 pipepl 112 328 0 309 2 1 1 2 0 8 0 fdescpl 488 563 0 547 3 0 3 3 0 8 0 filepl 152 4139 0 4036 6 1 5 6 0 8 1 lockfpl 104 156 0 155 1 0 1 1 0 8 0 lockfspl 48 48 0 47 1 0 1 1 0 8 0 sessionpl 112 20 0 9 1 0 1 1 0 8 0 pgrppl 48 28 0 17 1 0 1 1 0 8 0 ucredpl 96 497 0 488 1 0 1 1 0 8 0 zombiepl 144 547 0 547 1 0 1 1 0 8 1 processpl 896 580 0 547 4 0 4 4 0 8 0 procpl 632 1366 0 1323 5 0 5 5 0 8 1 srpgc 64 4 0 4 2 1 1 1 0 8 1 sosppl 128 13 0 13 1 1 0 1 0 8 0 sockpl 384 894 0 870 5 1 4 5 0 8 1 mcl64k 65536 8 0 0 1 0 1 1 0 8 0 mcl16k 16384 5 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 10 0 0 2 0 2 2 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 203 0 0 25 0 25 25 0 8 0 mtagpl 80 20 0 0 1 0 1 1 0 8 0 mbufpl 256 343 0 0 21 0 21 21 0 8 0 bufpl 256 9228 0 2180 441 0 441 441 0 8 0 anonpl 16 73768 0 58902 93 13 80 92 0 124 3 amapchunkpl 152 3514 0 3387 14 7 7 13 0 158 0 amappl16 192 3024 0 1956 69 15 54 65 0 8 0 amappl15 184 2 0 0 1 0 1 1 0 8 0 amappl14 176 48 0 46 1 0 1 1 0 8 0 amappl12 160 173 0 172 2 1 1 1 0 8 0 amappl11 152 59 0 44 1 0 1 1 0 8 0 amappl10 144 162 0 156 1 0 1 1 0 8 0 amappl9 136 646 0 640 1 0 1 1 0 8 0 amappl8 128 196 0 171 1 0 1 1 0 8 0 amappl7 120 197 0 187 1 0 1 1 0 8 0 amappl6 112 85 0 74 1 0 1 1 0 8 0 amappl5 104 301 0 287 1 0 1 1 0 8 0 amappl4 96 816 0 788 1 0 1 1 0 8 0 amappl3 88 149 0 141 1 0 1 1 0 8 0 amappl2 80 3438 0 3366 3 1 2 3 0 8 0 amappl1 72 22495 0 22049 25 15 10 20 0 8 0 amappl 80 1660 0 1619 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 17 0 17 1 1 0 1 0 8 0 aobjpl 64 83 0 0 2 0 2 2 0 8 0 uaddrrnd 24 571 0 547 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 571 0 547 1 0 1 1 0 8 0 vmmpekpl 168 8644 0 8609 2 0 2 2 0 8 0 vmmpepl 168 78037 0 75832 163 24 139 139 0 357 39 vmsppl 368 562 0 547 2 0 2 2 0 8 0 pdppl 4096 1149 0 1106 6 0 6 6 0 8 0 pvpl 32 226128 0 208269 218 12 206 218 0 265 26 pmappl 232 570 0 551 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 618 0 3 18 0 18 18 0 8 0