panic: pr_find_pagehead: mbufpl: page header missing Stopped at db_enter+0xa: popq %rbp TID PID UID PRFLAGS PFLAGS CPU COMMAND db_enter() at db_enter+0xa panic() at panic+0x147 pool_do_put(ffffff0006000100,ffffffff81e99280) at pool_do_put+0x339 pool_put(0,ffffff0006000100) at pool_put+0x37 m_free(ffffff0006000100) at m_free+0x12c mq_purge(ffff800000ad3480) at mq_purge+0x6d switchclose(ffff8000ffffd070,ffff800014aaa048,ffffffff81245447,ffff800014aa9ff0) at switchclose+0x77 spec_close(ffffffff81e300a8) at spec_close+0x271 VOP_CLOSE(ffffff0037cca670,ffff8000ffffd070,ffffff003f7c76c0,42) at VOP_CLOSE+0x5f vn_closefile(ffff8000ffffd070,ffffff00376901e0) at vn_closefile+0xfc fdrop(ffffff00376901e0,ffff8000ffffd070) at fdrop+0xa4 closef(ffff8000ffffd070,ffffff00365ef1b0) at closef+0xd5 fdfree(ffff8000149d0620) at fdfree+0x98 exit1(ffff800014aaa310,ffff8000ffffd070,ffff8000149d0620) at exit1+0x22f end trace frame: 0xffff800014aaa230, 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> ddb> set $lines = 0 ddb> show panic pr_find_pagehead: mbufpl: page header missing ddb> trace db_enter() at db_enter+0xa panic() at panic+0x147 pool_do_put(ffffff0006000100,ffffffff81e99280) at pool_do_put+0x339 pool_put(0,ffffff0006000100) at pool_put+0x37 m_free(ffffff0006000100) at m_free+0x12c mq_purge(ffff800000ad3480) at mq_purge+0x6d switchclose(ffff8000ffffd070,ffff800014aaa048,ffffffff81245447,ffff800014aa9ff0) at switchclose+0x77 spec_close(ffffffff81e300a8) at spec_close+0x271 VOP_CLOSE(ffffff0037cca670,ffff8000ffffd070,ffffff003f7c76c0,42) at VOP_CLOSE+0x5f vn_closefile(ffff8000ffffd070,ffffff00376901e0) at vn_closefile+0xfc fdrop(ffffff00376901e0,ffff8000ffffd070) at fdrop+0xa4 closef(ffff8000ffffd070,ffffff00365ef1b0) at closef+0xd5 fdfree(ffff8000149d0620) at fdfree+0x98 exit1(ffff800014aaa310,ffff8000ffffd070,ffff8000149d0620) at exit1+0x22f sys_exit(ffffffff814c2af3,ffff800014aaa230,ffff800014aaa310) at sys_exit+0x13 syscall(0) at syscall+0x3e4 Xsyscall(6,1,0,1,0,7f7ffffdf360) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffdf310, count: -17 ddb> show registers rdi 0xffffffff81e28ee0 kprintf_mutex rsi 0x5 rbp 0xffff800014aa9e00 rbx 0xffff800014aa9ea0 rdx 0x3fd rcx 0 rax 0 r8 0xffff800014aa9dd0 r9 0x8080808080808080 r10 0xdfc28b95e4904ae6 r11 0xffffffff8142ad10 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff800014aa9e10 r14 0x100 r15 0xffffffff81c161b0 apollo_udma100_tim+0x6a2d rip 0xffffffff81a90bda db_enter+0xa cs 0x8 rflags 0x246 rsp 0xffff800014aa9e00 ss 0x10 db_enter+0xa: popq %rbp ddb> show proc PROC (syz-executor0) pid=231034 stat=onproc flags process=1018 proc=2000 pri=50, usrpri=66, nice=20 forw=0xffffffffffffffff, list=0xffff800014a332d0,0xffffffff81e94fe8 process=0xffff8000149d0620 user=0xffff800014aa5000, vmspace=0xffffff003f12b000 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 52896 97390 51156 0 3 0x82 nanosleep syz-executor0 51156 402951 85978 0 3 0x82 thrsleep syz-execprog 51156 192893 85978 0 3 0x4000082 thrsleep syz-execprog 51156 512975 85978 0 3 0x4000082 thrsleep syz-execprog 51156 440696 85978 0 3 0x4000082 thrsleep syz-execprog 51156 449065 85978 0 3 0x4000082 kqread syz-execprog 51156 482514 85978 0 3 0x4000082 thrsleep syz-execprog 51156 263884 85978 0 3 0x4000082 thrsleep syz-execprog 85978 410770 72445 0 3 0x10008a pause ksh 72445 500055 61029 0 3 0x92 select sshd 15118 505558 1 0 3 0x100083 ttyin getty 61029 421953 1 0 3 0x80 select sshd 63065 252719 37417 73 3 0x100090 kqread syslogd 37417 402341 1 0 3 0x100082 netio syslogd 7525 275074 1 77 3 0x100090 poll dhclient 67726 108035 1 0 3 0x80 poll dhclient 94050 276981 0 0 2 0x14200 zerothread 84868 423868 0 0 3 0x14200 aiodoned aiodoned 68206 241820 0 0 3 0x14200 syncer update 23873 324315 0 0 3 0x14200 cleaner cleaner 24826 425688 0 0 3 0x14200 reaper reaper 7681 198275 0 0 3 0x14200 pgdaemon pagedaemon 13116 69064 0 0 3 0x14200 bored crynlk 8816 401733 0 0 3 0x14200 bored crypto 69649 292631 0 0 3 0x40014200 acpi0 acpi0 11140 131677 0 0 3 0x14200 bored softnet 7736 204232 0 0 3 0x14200 bored systqmp 21324 298616 0 0 3 0x14200 bored systq 77400 430837 0 0 3 0x40014200 bored softclock 7060 291622 0 0 3 0x40014200 idle0 1 503016 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper