panic: pool_do_get: mbufpl free list modified: page 0xfffffd803f02f000; item addr 0xfffffd803f02f400; offset 0x0=0x0 != 0xecd56dae074cb91d Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 37421 43172 0 0x12 0 0 sshd 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_do_get(ffffffff8259b180,2,ffff800014866208) at pool_do_get+0x42a sys/kern/subr_pool.c:746 pool_get(ffffffff8259b180,2) at pool_get+0xb5 sys/kern/subr_pool.c:581 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000a60320) at tcp_output+0x1408 tcp_usrreq(fffffd80363de188,9,fffffd803f02f700,0,0,ffff8000ffff4010) at tcp_usrreq+0xa54 sosend(fffffd80363de188,0,ffff800014866668,0,0,80) at sosend+0x63d sys/kern/uipc_socket.c:524 dofilewritev(ffff8000ffff4010,4,ffff800014866668,0,ffff800014866750) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff8000ffff4010,ffff800014866700,ffff800014866750) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff8000148667d0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,4,1fccbd11616b,4,4,1fcee3efd480) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc1d40, 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> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic pool_do_get: mbufpl free list modified: page 0xfffffd803f02f000; item addr 0xfffffd803f02f400; offset 0x0=0x0 != 0xecd56dae074cb91d ddb> 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_do_get(ffffffff8259b180,2,ffff800014866208) at pool_do_get+0x42a sys/kern/subr_pool.c:746 pool_get(ffffffff8259b180,2) at pool_get+0xb5 sys/kern/subr_pool.c:581 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000a60320) at tcp_output+0x1408 tcp_usrreq(fffffd80363de188,9,fffffd803f02f700,0,0,ffff8000ffff4010) at tcp_usrreq+0xa54 sosend(fffffd80363de188,0,ffff800014866668,0,0,80) at sosend+0x63d sys/kern/uipc_socket.c:524 dofilewritev(ffff8000ffff4010,4,ffff800014866668,0,ffff800014866750) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff8000ffff4010,ffff800014866700,ffff800014866750) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff8000148667d0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,4,1fccbd11616b,4,4,1fcee3efd480) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc1d40, count: -12 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014866070 rbx 0xffff800014866120 rdx 0x2 rcx 0x1 rax 0x1 r8 0xffff800014866030 r9 0x1 r10 0xbfe4e95795d0460 r11 0xbd2676bd8c5b4201 r12 0x3000000008 r13 0xffff800014866080 r14 0x100 r15 0x1 rip 0xffffffff81fe2d68 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014866060 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=37421 stat=onproc flags process=12 proc=0 pri=51, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff58c0,0xffff8000ffff4788 process=0xffff8000148a3458 user=0xffff800014861000, vmspace=0xfffffd803f013770 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 45783 49071 94224 0 3 0x2 biowait syz-executor.0 94224 436676 34847 0 3 0x82 thrsleep syz-execprog 94224 495514 34847 0 2 0x4000002 syz-execprog 94224 345960 34847 0 3 0x4000082 thrsleep syz-execprog 94224 297277 34847 0 3 0x4000082 thrsleep syz-execprog 94224 515205 34847 0 2 0x4000002 syz-execprog 94224 157678 34847 0 3 0x4000082 thrsleep syz-execprog 94224 297955 34847 0 3 0x4000082 thrsleep syz-execprog 34847 235884 43172 0 3 0x10008a pause ksh *43172 37421 21585 0 7 0x12 sshd 52191 402993 1 0 3 0x100083 ttyin getty 21585 331441 1 0 3 0x80 select sshd 26966 378227 24805 73 3 0x100090 kqread syslogd 24805 410332 1 0 3 0x100082 netio syslogd 3691 123257 1 77 3 0x100090 poll dhclient 42626 384261 1 0 3 0x80 poll dhclient 87140 150474 0 0 3 0x14200 pgzero zerothread 12261 186032 0 0 3 0x14200 aiodoned aiodoned 90987 400576 0 0 3 0x14200 syncer update 78230 397630 0 0 3 0x14200 cleaner cleaner 52465 367430 0 0 3 0x14200 reaper reaper 41942 32094 0 0 3 0x14200 pgdaemon pagedaemon 38232 378734 0 0 3 0x14200 bored crynlk 57745 395136 0 0 3 0x14200 bored crypto 81651 263905 0 0 3 0x40014200 acpi0 acpi0 84360 412907 0 0 3 0x14200 bored softnet 17536 171861 0 0 3 0x14200 bored systqmp 45421 72601 0 0 3 0x14200 bored systq 51615 397449 0 0 3 0x40014200 bored softclock 26376 264078 0 0 3 0x40014200 idle0 57723 193862 0 0 3 0x14200 bored smr 1 375900 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9433 6309K 6309K 78643K 10526 0 0 pcb 13 8K 8K 78643K 13 0 0 rtable 77 2K 2K 78643K 155 0 0 ifaddr 28 8K 8K 78643K 1624 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 14 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1180 74K 74K 78643K 1185 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 1K 78643K 2 0 0 VM map 2 0K 0K 78643K 2 0 0 sem 2 0K 0K 78643K 2 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 2 4K 12K 78643K 1614 0 0 proc 47 38K 54K 78643K 307 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 in_multi 22 1K 1K 78643K 22 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 18 79K 79K 78643K 18 0 0 exec 0 0K 1K 78643K 172 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 65 11K 11K 78643K 2450 0 0 UVM aobj 2 2K 2K 78643K 2 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 NDP 4 0K 0K 78643K 6 0 0 temp 39 3517K 3581K 78643K 6252 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 4 0 1 1 0 1 1 0 8 0 rtpcb 80 17 0 15 1 0 1 1 0 8 0 rtentry 112 34 0 4 1 0 1 1 0 8 0 unpcb 120 27 0 19 1 0 1 1 0 8 0 syncache 264 5 0 5 1 1 0 1 0 8 0 tcpcb 544 8 0 5 1 0 1 1 0 8 0 inpcb 280 1623 0 1617 1 0 1 1 0 8 0 nd6 48 2 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 168 0 2 11 0 11 11 0 8 0 art_table 32 169 0 2 2 0 2 2 0 8 0 art_node 16 33 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3009 0 1615 45 0 45 45 0 8 0 ffsino 240 3009 0 1615 83 0 83 83 0 8 1 nchpl 144 4845 0 3242 60 0 60 60 0 8 0 uvmvnodes 72 3018 0 0 55 0 55 55 0 8 0 vnodes 208 3018 0 0 159 0 159 159 0 8 0 namei 1024 10225 0 10225 2 1 1 1 0 8 1 scxspl 192 13725 0 13724 8 7 1 7 0 8 0 plimitpl 152 14 0 8 1 0 1 1 0 8 0 sigapl 432 1793 0 1782 2 0 2 2 0 8 0 knotepl 112 39 0 28 1 0 1 1 0 8 0 kqueuepl 104 2 0 0 1 0 1 1 0 8 0 pipepl 112 138 0 125 2 1 1 1 0 8 0 fdescpl 424 1794 0 1782 2 0 2 2 0 8 0 filepl 120 4170 0 4117 2 0 2 2 0 8 0 lockfpl 104 5 0 4 1 0 1 1 0 8 0 lockfspl 48 3 0 2 1 0 1 1 0 8 0 sessionpl 112 18 0 9 1 0 1 1 0 8 0 pgrppl 48 18 0 9 1 0 1 1 0 8 0 ucredpl 96 47 0 40 1 0 1 1 0 8 0 zombiepl 144 1782 0 1782 2 1 1 1 0 8 1 processpl 864 1808 0 1782 4 0 4 4 0 8 0 procpl 632 1814 0 1782 3 0 3 3 0 8 0 sockpl 384 1667 0 1651 2 0 2 2 0 8 0 mcl4k 4096 10 0 10 1 1 0 1 0 8 0 mcl2k 2048 5481 0 5448 8 3 5 8 0 8 0 mtagpl 80 2 0 2 1 1 0 1 0 8 0 mbufpl 256 12707 0 12647 8 3 5 6 0 8 0 mbufpl: pool(0xffffffff8259b180:mbufpl): free list modified: page 0xfffffd803f02f000; item ordinal 0; addr 0xfffffd803f02f400 (p 0xfffffd803f7cc000); offset 0x0=0x0 bufpl 256 7381 0 2922 279 0 279 279 0 8 0 anonpl 16 62484 0 60081 17 7 10 13 0 62 0 amapchunkpl 152 2474 0 2415 5 2 3 5 0 158 0 amappl16 192 6617 0 6529 5 0 5 5 0 8 0 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 21 0 19 2 1 1 1 0 8 0 amappl13 168 1598 0 1597 1 0 1 1 0 8 0 amappl12 160 8 0 6 1 0 1 1 0 8 0 amappl11 152 43 0 32 1 0 1 1 0 8 0 amappl10 144 11 0 9 2 1 1 1 0 8 0 amappl9 136 427 0 421 1 0 1 1 0 8 0 amappl8 128 116 0 107 1 0 1 1 0 8 0 amappl7 120 30 0 26 1 0 1 1 0 8 0 amappl6 112 71 0 64 1 0 1 1 0 8 0 amappl5 104 122 0 113 1 0 1 1 0 8 0 amappl4 96 3619 0 3592 1 0 1 1 0 8 0 amappl3 88 117 0 112 1 0 1 1 0 8 0 amappl2 80 4037 0 3984 4 2 2 3 0 8 0 amappl1 72 26102 0 25716 27 18 9 20 0 8 0 amappl 80 2028 0 2003 1 0 1 1 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 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1794 0 1782 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1794 0 1782 1 0 1 1 0 8 0 vmmpekpl 168 9375 0 9360 1 0 1 1 0 8 0 vmmpepl 168 99110 0 98215 89 39 50 77 0 357 10 vmsppl 272 1793 0 1782 1 0 1 1 0 8 0 pdppl 4096 3594 0 3564 5 0 5 5 0 8 0 pvpl 32 269188 0 264457 115 30 85 112 0 265 46 pmappl 200 1793 0 1782 1 0 1 1 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 405 0 10 12 0 12 12 0 8 0