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(ffffffff818e4124,ffff8000211dd580,ffff8000210a2e28,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2e28,ffff8000211d8000) 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,ffff800000ad6000,ffffffffffffffff,0,9,ffff8000210a2e28) at alltraps_kern+0x7b ptsignal(1ae3,ffff8000210a2e28,ffff8000210b6340) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211dd810) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211dd810,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211dd810,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2e28,3,0,ffff8000210b6408) at tsleep+0x142 single_thread_set(ffff8000210a2e28,ffff8000210a2e28,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a2e28,ffff8000210a2e28,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a2e28,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211dd9e0, 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(ffffffff818e4124,ffff8000211dd580,ffff8000210a2e28,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2e28,ffff8000211d8000) 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,ffff800000ad6000,ffffffffffffffff,0,9,ffff8000210a2e28) at alltraps_kern+0x7b ptsignal(1ae3,ffff8000210a2e28,ffff8000210b6340) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211dd810) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211dd810,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211dd810,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2e28,3,0,ffff8000210b6408) at tsleep+0x142 single_thread_set(ffff8000210a2e28,ffff8000210a2e28,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a2e28,ffff8000210a2e28,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a2e28,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210a2e28) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1500 [inline] postsig(100,ffff8000210a2e28) at postsig+0x3ea sys/kern/kern_sig.c:1432 userret(0) at userret+0x11b sys/kern/kern_sig.c:1882 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(6,58,9ba81420000,53,0,9ba81419560) at Xsyscall+0x128 end of kernel end trace frame: 0x9ba9e4f0150, count: -18 ddb{1}> show registers rdi 0xffffffff81e337f8 kprintf_mutex rsi 0xffffffff81696879 db_enter+0x9 rbp 0xffff8000211dd4e0 rbx 0xffff8000211dd580 rdx 0xffff800000ad6000 rcx 0x3bf9 __ALIGN_SIZE+0x2bf9 rax 0xffff800000ad6000 r8 0xffff8000211dd4b0 r9 0x8080808080808080 r10 0x52b972a19a4823b3 r11 0xffffffff8181f470 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211dd4f0 r14 0x100 r15 0xffffffff81bf4e1e cmd0646_9_tim_udma+0x1f12c rip 0xffffffff8169687a db_enter+0xa cs 0x8 rflags 0x206 rsp 0xffff8000211dd4e0 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor1) pid=90046 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210a3788,0xffffffff81eb7cb0 process=0xffff8000210b6340 user=0xffff8000211d8000, vmspace=0xffffff00714daa60 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 29048 224470 83877 65534 2 0x4081010 syz-executor1 *29048 90046 83877 65534 3 0x4003010 suspend syz-executor1 9395 244615 55642 65534 2 0x10 syz-executor0 9395 440154 55642 65534 3 0x4000090 poll syz-executor0 9395 286559 55642 65534 2 0x4000010 syz-executor0 55642 2792 75868 65534 3 0x90 nanosleep syz-executor0 75868 86758 2942 0 3 0x82 wait syz-executor0 83877 147060 38037 65534 3 0x90 nanosleep syz-executor1 38037 317032 2942 0 3 0x82 wait syz-executor1 82540 193768 0 0 3 0x14200 bored sosplice 2942 206645 77018 0 3 0x82 thrsleep syz-fuzzer 2942 491451 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 201327 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 352697 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 497728 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 469178 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 442389 77018 0 3 0x4000082 kqread syz-fuzzer 2942 299241 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 179417 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 151917 77018 0 3 0x4000082 thrsleep syz-fuzzer 2942 521009 77018 0 3 0x4000082 thrsleep syz-fuzzer 77018 123629 62120 0 3 0x10008a pause ksh 62120 399208 25581 0 3 0x92 select sshd 87798 204088 1 0 3 0x100083 ttyin getty 25581 157192 1 0 3 0x80 select sshd 20768 106125 49024 73 3 0x100090 kqread syslogd 49024 232528 1 0 3 0x100082 netio syslogd 30493 454528 1 77 3 0x100090 poll dhclient 39152 500137 1 0 3 0x80 poll dhclient 18478 203768 0 0 2 0x14200 zerothread 19592 365662 0 0 3 0x14200 aiodoned aiodoned 62272 338141 0 0 3 0x14200 syncer update 89568 336605 0 0 3 0x14200 cleaner cleaner 33246 224111 0 0 3 0x14200 reaper reaper 49394 75689 0 0 3 0x14200 pgdaemon pagedaemon 67002 104618 0 0 3 0x14200 bored crynlk 70798 482900 0 0 3 0x14200 bored crypto 26477 405435 0 0 3 0x40014200 acpi0 acpi0 58263 178953 0 0 3 0x40014200 idle1 94662 393506 0 0 3 0x14200 bored softnet 92504 468882 0 0 3 0x14200 bored systqmp 22107 293948 0 0 3 0x14200 bored systq 46318 418987 0 0 3 0x40014200 bored softclock 89504 70475 0 0 3 0x40014200 idle0 1 44576 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper