kern.securelevel: 0 -> 1 creating runtime link editor directory cache. preserving editor files. starting network daemons: sshd. starting local daemons:. Sat Dec 1 01:26:54 PST 2018 OpenBSD/amd64 (worker.syzkaller) (tty00) Warning: Permanently added '10.128.10.12' (ECDSA) to the list of known hosts. executing program login: kernel: protection fault trap, code=0 Stopped at m_extfree+0x3d: movq %rax,0x90(%r15) ddb> ddb> set $lines = 0 ddb> show panic the kernel did not panic ddb> trace m_extfree(eeae323926dacfb9) at m_extfree+0x3d m_free(ffffff006e3b2800) at m_free+0xee m_freem(16) at m_freem+0x2d soreceive(0,ffffff006e708908,0,0,ffff8000210fa960,ffff8000210fa870) at soreceive+0x1131 recvit(ffff8000210fa990,ffff8000210faa98,ffff8000210faa80,ffff8000210c3078,0) at recvit+0x28c sys_recvmsg(ffff8000210fab20,ffff8000210c3078,ffff8000210a5660) at sys_recvmsg+0x120 syscall(0) at syscall+0x3e4 Xsyscall(6,0,0,0,1,7f7ffffd8118) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd80d0, count: -8 ddb> show registers rdi 0x7 rsi 0x42 rbp 0xffff8000210fa760 rbx 0 rdx 0x4110 __ALIGN_SIZE+0x3110 rcx 0xffffffff81e5dcc0 mbstat_boot_boot_cpumem rax 0xe1311bd068d226d1 r8 0 r9 0xffff8000210c3078 r10 0xeeae323926dacfb9 r11 0xffffffff815aaa10 pool_lock_mtx_leave r12 0xdead __ALIGN_SIZE+0xcead r13 0xffffff006e708908 r14 0xffffff006e3b2800 r15 0x19fd241911c88e48 rip 0xffffffff8151b69d m_extfree+0x3d cs 0x8 rflags 0x10246 __ALIGN_SIZE+0xf246 rsp 0xffff8000210fa750 ss 0x10 m_extfree+0x3d: movq %rax,0x90(%r15) ddb> show proc PROC (syz-executor2746) pid=43702 stat=onproc flags process=2 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000210c32d0,0xffffffff81e98cf0 process=0xffff8000210a5660 user=0xffff8000210f5000, vmspace=0xffffff007f12b738 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND *79018 43702 95832 0 7 0x2 syz-executor2746 95832 427331 55680 0 3 0x10008a pause ksh 55680 313355 24267 0 3 0x92 select sshd 10602 288144 1 0 3 0x100083 ttyin getty 24267 237753 1 0 3 0x80 select sshd 90806 332710 7968 73 3 0x100090 kqread syslogd 7968 520884 1 0 3 0x100082 netio syslogd 88963 201487 1 77 3 0x100090 poll dhclient 12226 54954 1 0 3 0x80 poll dhclient 16290 426033 0 0 2 0x14200 zerothread 78023 377457 0 0 3 0x14200 aiodoned aiodoned 65835 304055 0 0 3 0x14200 syncer update 25536 172965 0 0 3 0x14200 cleaner cleaner 52190 319551 0 0 3 0x14200 reaper reaper 95903 297620 0 0 3 0x14200 pgdaemon pagedaemon 67386 496933 0 0 3 0x14200 bored crynlk 78545 3126 0 0 3 0x14200 bored crypto 24821 162148 0 0 3 0x40014200 acpi0 acpi0 44462 326116 0 0 3 0x14200 bored softnet 67132 455602 0 0 3 0x14200 bored systqmp 23929 228998 0 0 3 0x14200 bored systq 68458 210791 0 0 3 0x40014200 bored softclock 45918 497678 0 0 3 0x40014200 idle0 1 494986 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb>