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(ffffffff8172be34,ffff80002112b430,ffff800021085778,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff800021085778,ffff800021126000) 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(6,82000,ffffffffffffffff,0,9,ffff800021085778) at alltraps_kern+0x7b ptsignal(17ae,ffff800021085778,ffff800021071620) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff80002112b6c0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff80002112b6c0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff80002112b6c0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff800021085778,3,0,ffff8000210716e8) at tsleep+0x142 single_thread_set(ffff800021085778,ffff800021085778,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff800021085778,ffff800021085778,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff800021085778,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff80002112b890, 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(ffffffff8172be34,ffff80002112b430,ffff800021085778,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff800021085778,ffff800021126000) 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(6,82000,ffffffffffffffff,0,9,ffff800021085778) at alltraps_kern+0x7b ptsignal(17ae,ffff800021085778,ffff800021071620) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff80002112b6c0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff80002112b6c0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff80002112b6c0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff800021085778,3,0,ffff8000210716e8) at tsleep+0x142 single_thread_set(ffff800021085778,ffff800021085778,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff800021085778,ffff800021085778,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff800021085778,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff800021085778) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1500 [inline] postsig(100,ffff800021085778) 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(6,58,3ceb4e87a00,53,0,3cecb9d9a40) at Xsyscall+0x128 end of kernel end trace frame: 0x3cf36212fb0, count: -18 ddb{0}> show registers rdi 0xffffffff81e3d210 kprintf_mutex rsi 0x5 rbp 0xffff80002112b390 rbx 0xffff80002112b430 rdx 0x3fd rcx 0 rax 0x1 r8 0xffff80002112b360 r9 0x8080808080808080 r10 0 r11 0xffffffff816984e0 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff80002112b3a0 r14 0x100 r15 0xffffffff81bf66f0 cmd0646_9_tim_udma+0x1ebfb rip 0xffffffff8188a89a db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff80002112b390 ss 0x10 db_enter+0xa: popq %rbp ddb{0}> show proc PROC (syz-executor5550) pid=119238 stat=sleep flags process=1000 proc=4002000 pri=50, usrpri=50, nice=20 forw=0x0, list=0xffff8000210852c8,0xffff800021084978 process=0xffff800021071620 user=0xffff800021126000, vmspace=0xffffff007f125528 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND *15395 119238 28346 0 3 0x4003000 suspend syz-executor5550 15395 417257 28346 0 2 0x4081000 syz-executor5550 28346 284878 94619 0 3 0x80 nanosleep syz-executor5550 60014 217522 94619 0 3 0x80 nanosleep syz-executor5550 94619 71961 32712 0 3 0x82 nanosleep syz-executor5550 32712 564 76317 0 3 0x10008a pause ksh 76317 67270 53563 0 3 0x92 select sshd 61787 344689 1 0 3 0x100083 ttyin getty 53563 340940 1 0 3 0x80 select sshd 96462 163327 62857 73 3 0x100090 kqread syslogd 62857 51166 1 0 3 0x100082 netio syslogd 82747 423381 1 77 3 0x100090 poll dhclient 61770 477583 1 0 3 0x80 poll dhclient 44288 141028 0 0 2 0x14200 zerothread 2949 95657 0 0 3 0x14200 aiodoned aiodoned 59569 2744 0 0 3 0x14200 syncer update 97615 18787 0 0 3 0x14200 cleaner cleaner 31075 516634 0 0 3 0x14200 reaper reaper 92050 406702 0 0 3 0x14200 pgdaemon pagedaemon 57938 307153 0 0 3 0x14200 bored crynlk 35754 9636 0 0 3 0x14200 bored crypto 28435 50474 0 0 3 0x40014200 acpi0 acpi0 27223 311074 0 0 3 0x40014200 idle1 51849 92683 0 0 3 0x14200 bored softnet 87709 391602 0 0 3 0x14200 bored systqmp 36507 388915 0 0 3 0x14200 bored systq 6364 371912 0 0 3 0x40014200 bored softclock 91853 126411 0 0 3 0x40014200 idle0 1 71431 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}>