panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd8068085300+24 0xd8dd75ab02d47f85!=0x2722882b6adc2f85 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 174069 29105 0 0x2 0 1K syz-executor.0 *501898 24399 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff82407a62) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828c6318) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828c6318) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828c6318,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000adb280) at tcp_output+0x14e6 tcp_usrreq(fffffd806eaf2c88,9,fffffd8068085c00,0,0,ffff8000fffff648) at tcp_usrreq+0xa55 sosend(fffffd806eaf2c88,0,ffff800020e02878,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff8000fffff648,4,ffff800020e02878,0,ffff800020e02960) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff8000fffff648,ffff800020e02910,ffff800020e02960) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e029e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e029e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffed280, count: 3 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 pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd8068085300+24 0xd8dd75ab02d47f85!=0x2722882b6adc2f85 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff82407a62) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828c6318) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828c6318) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828c6318,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000adb280) at tcp_output+0x14e6 tcp_usrreq(fffffd806eaf2c88,9,fffffd8068085c00,0,0,ffff8000fffff648) at tcp_usrreq+0xa55 sosend(fffffd806eaf2c88,0,ffff800020e02878,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff8000fffff648,4,ffff800020e02878,0,ffff800020e02960) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff8000fffff648,ffff800020e02910,ffff800020e02960) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e029e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e029e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffed280, count: -12 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020e02270 rbx 0xffff800020e02320 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff800020e02230 r9 0xffffffff82193d9f kprintf+0x16f r10 0x1 r11 0xd8d7ad9dff407727 r12 0x3000000008 r13 0xffff800020e02280 r14 0x100 r15 0x1 rip 0xffffffff820d5aa8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020e02260 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (sshd) pid=501898 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffe778,0xffff8000ffffe020 process=0xffff8000ffffc000 user=0xffff800020dfd000, vmspace=0xfffffd806e910458 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 43146 479741 0 0 3 0x14200 bored sosplice 97444 200374 11499 0 3 0x82 piperd syz-executor.1 29105 174069 11499 0 7 0x2 syz-executor.0 11499 177659 1153 0 3 0x82 thrsleep syz-fuzzer 11499 359911 1153 0 3 0x4000082 nanosleep syz-fuzzer 11499 23302 1153 0 3 0x4000082 thrsleep syz-fuzzer 11499 83761 1153 0 3 0x4000082 thrsleep syz-fuzzer 11499 260175 1153 0 3 0x4000082 thrsleep syz-fuzzer 11499 191155 1153 0 3 0x4000082 thrsleep syz-fuzzer 11499 177828 1153 0 2 0x4000002 syz-fuzzer 11499 404875 1153 0 3 0x4000082 kqread syz-fuzzer 1153 193121 24399 0 3 0x10008a pause ksh *24399 501898 96456 0 7 0x12 sshd 50161 253556 1 0 3 0x100083 ttyin getty 96456 157272 1 0 3 0x80 select sshd 87533 523508 61010 74 3 0x100092 bpf pflogd 61010 456995 1 0 3 0x80 netio pflogd 94862 172492 8542 73 3 0x100090 kqread syslogd 8542 171171 1 0 3 0x100082 netio syslogd 68454 382804 1 77 3 0x100090 poll dhclient 44119 51236 1 0 3 0x80 poll dhclient 34009 52285 0 0 3 0x14200 bored smr 7420 342276 0 0 3 0x14200 pgzero zerothread 53172 417502 0 0 3 0x14200 aiodoned aiodoned 44582 491381 0 0 3 0x14200 syncer update 35125 170711 0 0 3 0x14200 cleaner cleaner 20873 149335 0 0 3 0x14200 reaper reaper 68211 475661 0 0 3 0x14200 pgdaemon pagedaemon 74146 249069 0 0 3 0x14200 bored crynlk 92482 1793 0 0 3 0x14200 bored crypto 79906 384796 0 0 3 0x40014200 acpi0 acpi0 83305 464414 0 0 3 0x40014200 idle1 99339 163713 0 0 3 0x14200 bored softnet 48219 23581 0 0 3 0x14200 bored systqmp 91919 393888 0 0 3 0x14200 bored systq 44620 459891 0 0 3 0x40014200 bored softclock 26691 133783 0 0 3 0x40014200 idle0 1 199465 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 24399 (sshd) thread 0xffff8000fffff648 (501898) ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9509 6427K 6792K 78643K 11029 0 pcb 13 8K 8K 78643K 55 0 rtable 109 4K 7K 78643K 335 0 ifaddr 72 14K 14K 78643K 117 0 sysctl 2 0K 0K 78643K 2 0 counters 43 33K 34K 78643K 51 0 ioctlops 0 0K 4K 78643K 1513 0 iov 0 0K 16K 78643K 25 0 mount 1 1K 1K 78643K 1 0 vnodes 1220 77K 77K 78643K 1360 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 6 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 72 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 4 9K 25K 78643K 334 0 proc 63 63K 95K 78643K 467 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 26 0 in_multi 52 2K 2K 78643K 93 0 ether_multi 1 0K 0K 78643K 6 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 218 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 164 25K 42K 78643K 2001 0 UVM aobj 17 6K 6K 78643K 22 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 32 0 NDP 12 0K 0K 78643K 25 0 temp 127 3870K 3934K 78643K 2904 0 kqueue 3 4K 8K 78643K 7 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> 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 88 33 0 31 1 0 1 1 0 8 0 rtentry 112 56 0 12 2 0 2 2 0 8 0 unpcb 120 263 0 253 1 0 1 1 0 8 0 syncache 272 7 0 7 2 2 0 1 0 8 0 tcpqe 32 583 0 583 1 1 0 1 0 8 0 tcpcb 592 72 0 68 1 0 1 1 0 8 0 inpcb 296 248 0 241 3 1 2 2 0 8 1 rttmr 72 2 0 1 1 0 1 1 0 8 0 nd6 48 12 0 7 1 0 1 1 0 8 0 pkpcb 40 8 0 8 1 0 1 1 0 8 1 pfstscr 40 6 0 3 1 0 1 1 0 8 0 pffrag 232 6 0 6 2 1 1 1 0 482 1 pffrnode 88 6 0 6 2 1 1 1 0 8 1 pffrent 40 102 0 102 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 pfrktable 1344 26 0 26 2 1 1 1 0 8 1 pfstitem 24 47 0 7 1 0 1 1 0 8 0 pfstkey 112 51 0 11 2 0 2 2 0 8 0 pfstate 328 47 0 9 4 0 4 4 0 8 0 pfrule 1360 26 0 22 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 236 0 40 13 0 13 13 0 8 0 art_table 32 237 0 40 2 0 2 2 0 8 0 art_node 16 55 0 15 1 0 1 1 0 8 0 sysvmsgpl 40 58 0 18 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 66 0 56 1 0 1 1 0 8 0 shmpl 112 19 0 5 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1824 0 427 88 0 88 88 0 8 0 ffsino 272 1824 0 427 94 0 94 94 0 8 0 nchpl 144 2646 0 1036 60 0 60 60 0 8 0 uvmvnodes 72 1970 0 0 36 0 36 36 0 8 0 vnodes 208 1970 0 0 104 0 104 104 0 8 0 namei 1024 7105 0 7105 1 0 1 1 0 8 1 percpumem 16 36 0 4 1 0 1 1 0 8 0 vmpool 560 2 0 2 1 1 0 1 0 8 0 pfiaddrpl 120 7 0 7 2 1 1 1 0 8 1 scsiplug 72 1 0 1 1 0 1 1 0 8 1 scxspl 200 7027 0 7026 8 7 1 7 0 8 0 plimitpl 152 31 0 23 1 0 1 1 0 8 0 sigapl 424 550 0 519 4 0 4 4 0 8 0 futexpl 56 4927 0 4927 1 0 1 1 0 8 1 knotepl 112 66 0 46 1 0 1 1 0 8 0 kqueuepl 152 27 0 25 1 0 1 1 0 8 0 pipepl 304 121 0 110 2 0 2 2 0 8 1 fdescpl 496 534 0 519 3 0 3 3 0 8 0 filepl 152 3124 0 3022 5 0 5 5 0 8 1 lockfpl 104 41 0 40 1 0 1 1 0 8 0 lockfspl 48 15 0 14 1 0 1 1 0 8 0 sessionpl 120 18 0 7 1 0 1 1 0 8 0 pgrppl 48 24 0 13 1 0 1 1 0 8 0 ucredpl 96 219 0 210 1 0 1 1 0 8 0 zombiepl 144 519 0 519 1 0 1 1 0 8 1 processpl 1008 550 0 519 5 0 5 5 0 8 0 procpl 632 1175 0 1137 5 1 4 5 0 8 0 sosppl 144 5 0 5 1 1 0 1 0 8 0 sockpl 400 552 0 533 6 2 4 5 0 8 2 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 5 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 10 0 0 2 0 2 2 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 200 0 0 24 0 24 24 0 8 0 mtagpl 96 37 0 0 1 0 1 1 0 8 0 mbufpl 256 381 0 0 22 0 22 22 0 8 0 bufpl 280 3653 0 129 252 0 252 252 0 8 0 anonpl 16 76009 0 57981 100 10 90 90 0 124 17 amapchunkpl 152 3411 0 3114 26 12 14 26 0 158 0 amappl16 192 2818 0 1987 66 16 50 54 0 8 8 amappl15 184 2 0 1 1 0 1 1 0 8 0 amappl14 176 1 0 0 1 0 1 1 0 8 0 amappl13 168 90 0 84 1 0 1 1 0 8 0 amappl12 160 80 0 74 1 0 1 1 0 8 0 amappl11 152 52 0 37 1 0 1 1 0 8 0 amappl10 144 264 0 261 1 0 1 1 0 8 0 amappl9 136 366 0 364 1 0 1 1 0 8 0 amappl8 128 361 0 316 2 0 2 2 0 8 0 amappl7 120 364 0 351 1 0 1 1 0 8 0 amappl6 112 36 0 25 1 0 1 1 0 8 0 amappl5 104 435 0 419 1 0 1 1 0 8 0 amappl4 96 481 0 457 1 0 1 1 0 8 0 amappl3 88 142 0 134 1 0 1 1 0 8 0 amappl2 80 3385 0 3325 2 0 2 2 0 8 0 amappl1 72 24241 0 23818 23 13 10 18 0 8 0 amappl 80 1468 0 1392 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 21 0 5 1 0 1 1 0 8 0 uaddrrnd 24 536 0 521 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 536 0 521 1 0 1 1 0 8 0 vmmpekpl 168 7990 0 7954 2 0 2 2 0 8 0 vmmpepl 168 75461 0 73533 123 22 101 115 0 357 10 vmsppl 368 535 0 521 2 0 2 2 0 8 0 pdppl 4096 1079 0 1042 6 0 6 6 0 8 0 pvpl 32 223501 0 202391 224 10 214 214 0 265 41 pmappl 232 535 0 521 3 2 1 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 271 0 7 8 0 8 8 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff82407a62) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828c6318) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828c6318) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828c6318,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000adb280) at tcp_output+0x14e6 tcp_usrreq(fffffd806eaf2c88,9,fffffd8068085c00,0,0,ffff8000fffff648) at tcp_usrreq+0xa55 sosend(fffffd806eaf2c88,0,ffff800020e02878,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff8000fffff648,4,ffff800020e02878,0,ffff800020e02960) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff8000fffff648,ffff800020e02910,ffff800020e02960) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e029e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e029e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffed280, count: -12 ddb{0}> machine ddbcpu 1