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(ffffffff8183de84,ffff800021196f50,ffff800021084968,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff800021084968,ffff800021192000) 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,ffff800001ad7000,ffffffffffffffff,0,9,ffff800021084968) at alltraps_kern+0x7b ptsignal(1fd4,ffff800021084968,ffff8000210e6fe0) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211971e0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211971e0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211971e0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff800021084968,3,0,ffff8000210e70a8) at tsleep+0x142 single_thread_set(ffff800021084968,ffff800021084968,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff800021084968,ffff800021084968,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff800021084968,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211973b0, 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{0}> ddb{0}> set $lines = 0 ddb{0}> 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{0}> 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(ffffffff8183de84,ffff800021196f50,ffff800021084968,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff800021084968,ffff800021192000) 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,ffff800001ad7000,ffffffffffffffff,0,9,ffff800021084968) at alltraps_kern+0x7b ptsignal(1fd4,ffff800021084968,ffff8000210e6fe0) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211971e0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211971e0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211971e0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff800021084968,3,0,ffff8000210e70a8) at tsleep+0x142 single_thread_set(ffff800021084968,ffff800021084968,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff800021084968,ffff800021084968,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff800021084968,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff800021084968) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff800021084968) 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,daa01e63a00,53,0,daa02052940) at Xsyscall+0x128 end of kernel end trace frame: 0xda9b8a5a390, count: -18 ddb{0}> show registers rdi 0xffffffff81e404d8 kprintf_mutex rsi 0xffffffff8194aba9 db_enter+0x9 rbp 0xffff800021196eb0 rbx 0xffff800021196f50 rdx 0xffff800001ad7000 rcx 0x3cd2 __ALIGN_SIZE+0x2cd2 rax 0xffff800001ad7000 r8 0xffff800021196e80 r9 0x8080808080808080 r10 0x54a3077c6bb89b1d r11 0xffffffff81a74690 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff800021196ec0 r14 0x100 r15 0xffffffff81bf6660 cmd0646_9_tim_udma+0x20e62 rip 0xffffffff8194abaa db_enter+0xa cs 0x8 rflags 0x206 rsp 0xffff800021196eb0 ss 0x10 db_enter+0xa: popq %rbp ddb{0}> show proc PROC (syz-executor0) pid=304126 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff800021085778,0xffffffff81ef9af8 process=0xffff8000210e6fe0 user=0xffff800021192000, vmspace=0xffffff00657c4848 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 96423 344379 38666 65534 2 0x10 syz-executor1 96423 269368 38666 65534 2 0x4000010 syz-executor1 77297 159503 28094 65534 2 0x4081090 syz-executor0 *77297 304126 28094 65534 3 0x4003010 suspend syz-executor0 28094 291376 37150 65534 3 0x90 nanosleep syz-executor0 37150 477261 79335 0 3 0x82 wait syz-executor0 38666 386567 55914 65534 3 0x90 nanosleep syz-executor1 55914 25996 79335 0 3 0x82 wait syz-executor1 30015 501073 0 0 3 0x14200 bored sosplice 79335 393940 57806 0 3 0x82 thrsleep syz-fuzzer 79335 364809 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 440304 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 88251 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 339469 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 111707 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 301049 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 215981 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 247537 57806 0 3 0x4000082 thrsleep syz-fuzzer 79335 53849 57806 0 3 0x4000082 kqread syz-fuzzer 79335 379248 57806 0 3 0x4000082 thrsleep syz-fuzzer 57806 302398 19408 0 3 0x10008a pause ksh 19408 402002 74743 0 3 0x92 select sshd 51202 257529 1 0 3 0x100083 ttyin getty 74743 221321 1 0 3 0x80 select sshd 60800 297923 75193 73 3 0x100090 kqread syslogd 75193 379030 1 0 3 0x100082 netio syslogd 61511 190540 1 77 3 0x100090 poll dhclient 198 452337 1 0 3 0x80 poll dhclient 12145 174081 0 0 2 0x14200 zerothread 53198 222262 0 0 3 0x14200 aiodoned aiodoned 27665 66540 0 0 3 0x14200 syncer update 41513 332748 0 0 3 0x14200 cleaner cleaner 21740 336076 0 0 3 0x14200 reaper reaper 14630 152220 0 0 3 0x14200 pgdaemon pagedaemon 80220 163378 0 0 3 0x14200 bored crynlk 60841 348772 0 0 3 0x14200 bored crypto 47660 117626 0 0 3 0x40014200 acpi0 acpi0 61294 157183 0 0 3 0x40014200 idle1 25695 451054 0 0 3 0x14200 bored softnet 46448 371274 0 0 3 0x14200 bored systqmp 38590 296031 0 0 3 0x14200 bored systq 54311 248594 0 0 3 0x40014200 bored softclock 43205 236673 0 0 3 0x40014200 idle0 1 49103 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper