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,ffff8000211d8df0,ffff8000210a3530,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3530,ffff8000211d4000) 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,ffff800001cd7000,ffffffffffffffff,0,9,ffff8000210a3530) at alltraps_kern+0x7b ptsignal(2651,ffff8000210a3530,ffff8000210b6340) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211d9080) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211d9080,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211d9080,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a3530,3,0,ffff8000210b6408) at tsleep+0x142 single_thread_set(ffff8000210a3530,ffff8000210a3530,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210a3530,ffff8000210a3530,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff8000210a3530,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211d9250, 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,ffff8000211d8df0,ffff8000210a3530,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3530,ffff8000211d4000) 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,ffff800001cd7000,ffffffffffffffff,0,9,ffff8000210a3530) at alltraps_kern+0x7b ptsignal(2651,ffff8000210a3530,ffff8000210b6340) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211d9080) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211d9080,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211d9080,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a3530,3,0,ffff8000210b6408) at tsleep+0x142 single_thread_set(ffff8000210a3530,ffff8000210a3530,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210a3530,ffff8000210a3530,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff8000210a3530,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210a3530) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff8000210a3530) 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,a2ccfac5a00,53,0,a2cfc812a80) at Xsyscall+0x128 end of kernel end trace frame: 0xa2cd325bc20, count: -18 ddb{1}> show registers rdi 0xffffffff81e291a8 kprintf_mutex rsi 0xffffffff81a8b5c9 db_enter+0x9 rbp 0xffff8000211d8d50 rbx 0xffff8000211d8df0 rdx 0xffff800001cd7000 rcx 0x3fcb __ALIGN_SIZE+0x2fcb rax 0xffff800001cd7000 r8 0xffff8000211d8d20 r9 0x8080808080808080 r10 0xfaa61cf3c7b2fff9 r11 0xffffffff813a7780 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211d8d60 r14 0x100 r15 0xffffffff81bf3c19 cmd0646_9_tim_udma+0x20790 rip 0xffffffff81a8b5ca db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff8000211d8d50 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor1) pid=97818 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210a3080,0xffffffff81edc2c0 process=0xffff8000210b6340 user=0xffff8000211d4000, vmspace=0xffffff0074d36320 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 76530 296943 66344 65534 2 0x4081090 syz-executor1 *76530 97818 66344 65534 3 0x4003010 suspend syz-executor1 38702 470918 9081 65534 3 0x90 nanosleep syz-executor0 38702 326680 9081 65534 3 0x4000090 ttyout syz-executor0 38702 508315 9081 65534 3 0x4000090 ttyin syz-executor0 66344 246743 40416 65534 3 0x90 nanosleep syz-executor1 40416 221128 28028 0 3 0x82 wait syz-executor1 9081 435227 75287 65534 3 0x90 nanosleep syz-executor0 75287 464662 28028 0 3 0x82 wait syz-executor0 75752 85207 0 0 3 0x14200 bored sosplice 28028 220779 29946 0 3 0x82 thrsleep syz-fuzzer 28028 279373 29946 0 3 0x4000082 thrsleep syz-fuzzer 28028 489102 29946 0 3 0x4000082 thrsleep syz-fuzzer 28028 14363 29946 0 3 0x4000082 kqread syz-fuzzer 28028 100956 29946 0 3 0x4000082 thrsleep syz-fuzzer 28028 128745 29946 0 3 0x4000082 thrsleep syz-fuzzer 28028 330972 29946 0 3 0x4000082 thrsleep syz-fuzzer 28028 433475 29946 0 3 0x4000082 thrsleep syz-fuzzer 28028 250766 29946 0 3 0x4000082 thrsleep syz-fuzzer 28028 292826 29946 0 3 0x4000082 thrsleep syz-fuzzer 29946 136322 47006 0 3 0x10008a pause ksh 47006 81546 92587 0 3 0x92 select sshd 11236 281897 1 0 3 0x100083 ttyin getty 92587 10453 1 0 3 0x80 select sshd 26115 378342 92024 73 3 0x100090 kqread syslogd 92024 508850 1 0 3 0x100082 netio syslogd 59029 287294 1 77 3 0x100090 poll dhclient 65399 143044 1 0 3 0x80 poll dhclient 12483 385514 0 0 3 0x14200 pgzero zerothread 6562 9453 0 0 3 0x14200 aiodoned aiodoned 14037 306052 0 0 3 0x14200 syncer update 61128 29629 0 0 3 0x14200 cleaner cleaner 69278 292258 0 0 3 0x14200 reaper reaper 32798 274429 0 0 3 0x14200 pgdaemon pagedaemon 14689 437867 0 0 3 0x14200 bored crynlk 55815 506471 0 0 3 0x14200 bored crypto 62046 357818 0 0 3 0x40014200 acpi0 acpi0 67723 351668 0 0 3 0x40014200 idle1 45439 293237 0 0 3 0x14200 bored softnet 96158 210579 0 0 3 0x14200 bored systqmp 33984 109048 0 0 3 0x14200 bored systq 50466 234728 0 0 3 0x40014200 bored softclock 31586 38845 0 0 3 0x40014200 idle0 1 378475 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper