panic: kernel diagnostic assertion "__mp_lock_held(&sched_lock, curcpu()) == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_lock.c", line 63 Stopped at db_enter+0xa: popq %rbp TID PID UID PRFLAGS PFLAGS CPU COMMAND db_enter() at db_enter+0xa sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x147 sys/kern/subr_prf.c:208 __assert(ffffffff813e52b4,ffff800021189570,ffff8000210d8270,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210d8270,ffff800021184000) at _kernel_lock+0x125 sys/kern/kern_lock.c:63 pageflttrap() at pageflttrap+0x6c sys/arch/amd64/amd64/trap.c:163 kerntrap(9) at kerntrap+0x8d sys/arch/amd64/amd64/trap.c:294 alltraps_kern(6,ffff8000028d7000,ffffffffffffffff,0,9,ffff8000210d8270) at alltraps_kern+0x7b ptsignal(18f6,ffff8000210d8270,ffff8000210e6668) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021189800) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021189800,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021189800,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210d8270,3,0,ffff8000210e6730) at tsleep+0x142 single_thread_set(ffff8000210d8270,ffff8000210d8270,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210d8270,ffff8000210d8270,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff8000210d8270,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211899d0, 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{1}> ddb{1}> set $lines = 0 ddb{1}> show panic kernel diagnostic assertion "__mp_lock_held(&sched_lock, curcpu()) == 0" failed: file "/syzkaller/managers/setuid/kernel/sys/kern/kern_lock.c", line 63 ddb{1}> trace db_enter() at db_enter+0xa sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x147 sys/kern/subr_prf.c:208 __assert(ffffffff813e52b4,ffff800021189570,ffff8000210d8270,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210d8270,ffff800021184000) at _kernel_lock+0x125 sys/kern/kern_lock.c:63 pageflttrap() at pageflttrap+0x6c sys/arch/amd64/amd64/trap.c:163 kerntrap(9) at kerntrap+0x8d sys/arch/amd64/amd64/trap.c:294 alltraps_kern(6,ffff8000028d7000,ffffffffffffffff,0,9,ffff8000210d8270) at alltraps_kern+0x7b ptsignal(18f6,ffff8000210d8270,ffff8000210e6668) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021189800) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021189800,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021189800,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210d8270,3,0,ffff8000210e6730) at tsleep+0x142 single_thread_set(ffff8000210d8270,ffff8000210d8270,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210d8270,ffff8000210d8270,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff8000210d8270,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210d8270) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff8000210d8270) at postsig+0x3ea sys/kern/kern_sig.c:1420 userret(0) at userret+0x11b sys/kern/kern_sig.c:1870 syscall(0) at syscall+0x54d mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(0) at syscall+0x54d sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,58,2c9b6d3bc00,53,0,2ca14480600) at Xsyscall+0x128 end of kernel end trace frame: 0x2ca32173240, count: -18 ddb{1}> show registers rdi 0xffffffff81e291a8 kprintf_mutex rsi 0xffffffff81a8b5c9 db_enter+0x9 rbp 0xffff8000211894d0 rbx 0xffff800021189570 rdx 0xffff8000028d7000 rcx 0x3ef8 __ALIGN_SIZE+0x2ef8 rax 0xffff8000028d7000 r8 0xffff8000211894a0 r9 0x8080808080808080 r10 0xffa1bf7d4e1faa16 r11 0xffffffff813a7780 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211894e0 r14 0x100 r15 0xffffffff81bf3c19 cmd0646_9_tim_udma+0x20790 rip 0xffffffff81a8b5ca db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff8000211894d0 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor0) pid=422336 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210d9530,0xffffffff81edc2c0 process=0xffff8000210e6668 user=0xffff800021184000, vmspace=0xffffff00657e4218 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 90062 64883 65179 65534 3 0x10 biowait syz-executor1 79386 49967 71345 65534 2 0x4081090 syz-executor0 *79386 422336 71345 65534 3 0x4003010 suspend syz-executor0 65179 366641 78389 0 3 0x82 wait syz-executor1 71345 284009 60781 65534 3 0x90 nanosleep syz-executor0 60781 298117 78389 0 3 0x82 wait syz-executor0 44571 139056 0 0 3 0x14200 bored sosplice 78389 26498 69049 0 3 0x82 thrsleep syz-fuzzer 78389 207813 69049 0 3 0x4000082 nanosleep syz-fuzzer 78389 482273 69049 0 3 0x4000082 thrsleep syz-fuzzer 78389 374803 69049 0 3 0x4000082 thrsleep syz-fuzzer 78389 132680 69049 0 3 0x4000082 thrsleep syz-fuzzer 78389 59408 69049 0 3 0x4000082 thrsleep syz-fuzzer 78389 472006 69049 0 3 0x4000082 thrsleep syz-fuzzer 78389 461447 69049 0 3 0x4000082 thrsleep syz-fuzzer 78389 366243 69049 0 3 0x4000082 thrsleep syz-fuzzer 78389 384255 69049 0 3 0x4000082 kqread syz-fuzzer 69049 134022 71272 0 3 0x10008a pause ksh 71272 257036 61467 0 3 0x92 select sshd 49127 268585 1 0 3 0x100083 ttyin getty 61467 255364 1 0 3 0x80 select sshd 22547 420643 16401 73 3 0x100090 kqread syslogd 16401 135712 1 0 3 0x100082 netio syslogd 52179 521897 1 77 3 0x100090 poll dhclient 85174 178685 1 0 3 0x80 poll dhclient 596 327435 0 0 3 0x14200 pgzero zerothread 18410 456544 0 0 3 0x14200 aiodoned aiodoned 91884 424427 0 0 3 0x14200 syncer update 66046 456531 0 0 3 0x14200 cleaner cleaner 85961 223202 0 0 3 0x14200 reaper reaper 66289 9355 0 0 3 0x14200 pgdaemon pagedaemon 70784 244608 0 0 3 0x14200 bored crynlk 66651 483363 0 0 3 0x14200 bored crypto 25524 152375 0 0 3 0x40014200 acpi0 acpi0 59495 13727 0 0 3 0x40014200 idle1 61380 495453 0 0 3 0x14200 bored softnet 7107 290091 0 0 3 0x14200 bored systqmp 71963 507036 0 0 3 0x14200 bored systq 67626 475645 0 0 3 0x40014200 bored softclock 41518 275948 0 0 3 0x40014200 idle0 1 463774 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper