login: panic: pool_do_put: mcl64k: double pool_put: 0xffffff007082d000 Stopped at db_enter+0xa: popq %rbp TID PID UID PRFLAGS PFLAGS CPU COMMAND *478795 30599 0 0 0x4000000 0 syz-executor0 db_enter() at db_enter+0xa panic() at panic+0x147 pool_do_put(ffffff007082d000,ffffffff81eb9968) at pool_do_put+0x2e2 pool_put(0,ffffff007163c700) at pool_put+0x37 m_extfree(88ee6d8204e1bf39) at m_extfree+0xb1 m_free(ffffff007163c700) at m_free+0xee m_freem(16) at m_freem+0x2d soreceive(0,ffffff0064499918,ffff80002118a330,1000,ffff80002118a3c0,ffff80002118a2d0) at soreceive+0x1131 recvit(ffff80002118a3f0,ffff80002118a4f8,ffff80002118a4e0,ffff8000ffffc968,0) at recvit+0x28c sys_recvmsg(ffff80002118a580,ffff8000ffffc968,ffff80002105fca8) at sys_recvmsg+0x120 syscall(0) at syscall+0x3e4 Xsyscall(6,0,ffffffffffffffbf,0,3,15ba3060010) at Xsyscall+0x128 end of kernel end trace frame: 0x15df7061db0, 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> show panic pool_do_put: mcl64k: double pool_put: 0xffffff007082d000 ddb> trace db_enter() at db_enter+0xa panic() at panic+0x147 pool_do_put(ffffff007082d000,ffffffff81eb9968) at pool_do_put+0x2e2 pool_put(0,ffffff007163c700) at pool_put+0x37 m_extfree(88ee6d8204e1bf39) at m_extfree+0xb1 m_free(ffffff007163c700) at m_free+0xee m_freem(16) at m_freem+0x2d soreceive(0,ffffff0064499918,ffff80002118a330,1000,ffff80002118a3c0,ffff80002118a2d0) at soreceive+0x1131 recvit(ffff80002118a3f0,ffff80002118a4f8,ffff80002118a4e0,ffff8000ffffc968,0) at recvit+0x28c sys_recvmsg(ffff80002118a580,ffff8000ffffc968,ffff80002105fca8) at sys_recvmsg+0x120 syscall(0) at syscall+0x3e4 Xsyscall(6,0,ffffffffffffffbf,0,3,15ba3060010) at Xsyscall+0x128 end of kernel end trace frame: 0x15df7061db0, count: -12 ddb> show registers rdi 0xffffffff81e1c208 kprintf_mutex rsi 0xffffffff81030129 db_enter+0x9 rbp 0xffff80002118a030 rbx 0xffff80002118a0d0 rdx 0xffff800000ace000 rcx 0x1b7a __ALIGN_SIZE+0xb7a rax 0xffff800000ace000 r8 0xffff80002118a000 r9 0x8080808080808080 r10 0x88ee6d8204e1bf39 r11 0xffffffff81110b20 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff80002118a040 r14 0x100 r15 0xffffffff81c39f85 cy_pio_rec+0x56d5 rip 0xffffffff8103012a db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff80002118a030 ss 0x10 db_enter+0xa: popq %rbp ddb> show proc PROC (syz-executor0) pid=478795 stat=onproc flags process=0 proc=4000000 pri=58, usrpri=58, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffd2c8,0xffffffff81e98cf0 process=0xffff80002105fca8 user=0xffff800021185000, vmspace=0xffffff007f12b000 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 30599 293643 91416 0 2 0 syz-executor0 *30599 478795 91416 0 7 0x4000000 syz-executor0 56412 35413 93377 0 2 0 syz-executor1 56412 141156 93377 0 3 0x4000080 netio syz-executor1 2031 19278 1 0 3 0x100083 ttyin getty 33565 300042 0 0 3 0x14200 bored sosplice 91416 116120 50627 0 3 0x82 nanosleep syz-executor0 93377 410358 50627 0 3 0x82 nanosleep syz-executor1 50627 473457 56383 0 3 0x82 thrsleep syz-fuzzer 50627 288879 56383 0 3 0x4000082 thrsleep syz-fuzzer 50627 130340 56383 0 3 0x4000082 thrsleep syz-fuzzer 50627 233446 56383 0 3 0x4000082 thrsleep syz-fuzzer 50627 93820 56383 0 3 0x4000082 kqread syz-fuzzer 50627 316446 56383 0 3 0x4000082 thrsleep syz-fuzzer 50627 132184 56383 0 3 0x4000082 thrsleep syz-fuzzer 56383 335117 78351 0 3 0x10008a pause ksh 78351 123696 68321 0 3 0x92 select sshd 68321 254116 1 0 3 0x80 select sshd 43616 14139 84592 73 3 0x100090 kqread syslogd 84592 170273 1 0 3 0x100082 netio syslogd 82364 156182 1 77 3 0x100090 poll dhclient 99255 445825 1 0 3 0x80 poll dhclient 39777 181340 0 0 2 0x14200 zerothread 25811 469387 0 0 3 0x14200 aiodoned aiodoned 35900 213564 0 0 3 0x14200 syncer update 49581 215029 0 0 3 0x14200 cleaner cleaner 41475 368105 0 0 3 0x14200 reaper reaper 54221 355084 0 0 3 0x14200 pgdaemon pagedaemon 30131 136807 0 0 3 0x14200 bored crynlk 70757 454169 0 0 3 0x14200 bored crypto 2767 346309 0 0 3 0x40014200 acpi0 acpi0 59158 359793 0 0 3 0x14200 bored softnet 43830 338839 0 0 3 0x14200 bored systqmp 96819 386430 0 0 3 0x14200 bored systq 43339 264482 0 0 3 0x40014200 bored softclock 67871 161666 0 0 3 0x40014200 idle0 1 456308 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper