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(ffffffff814de554,ffff800021186d10,ffff8000210a2720,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2720,ffff800021182000) 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,ffff800000ad7000,ffffffffffffffff,0,9,ffff8000210a2720) at alltraps_kern+0x7b ptsignal(22cf,ffff8000210a2720,ffff8000210e72d8) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021186fa0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021186fa0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021186fa0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2720,3,0,ffff8000210e73a0) at tsleep+0x142 single_thread_set(ffff8000210a2720,ffff8000210a2720,0) at single_thread_set+0x26b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210a2720,ffff8000210a2720,0) at single_thread_set+0x26b sys/kern/kern_sig.c:2030 exit1(ffff8000210a2720,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff800021187170, 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(ffffffff814de554,ffff800021186d10,ffff8000210a2720,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2720,ffff800021182000) 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,ffff800000ad7000,ffffffffffffffff,0,9,ffff8000210a2720) at alltraps_kern+0x7b ptsignal(22cf,ffff8000210a2720,ffff8000210e72d8) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021186fa0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021186fa0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021186fa0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2720,3,0,ffff8000210e73a0) at tsleep+0x142 single_thread_set(ffff8000210a2720,ffff8000210a2720,0) at single_thread_set+0x26b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210a2720,ffff8000210a2720,0) at single_thread_set+0x26b sys/kern/kern_sig.c:2030 exit1(ffff8000210a2720,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210a2720) at postsig+0x408 sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff8000210a2720) at postsig+0x408 sys/kern/kern_sig.c:1420 userret(530) at userret+0x11b sys/kern/kern_sig.c:1870 syscall(0) at syscall+0x52f mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(0) at syscall+0x52f sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,58,dd75e75ec00,53,0,dd7eaddfa60) at Xsyscall+0x128 end of kernel end trace frame: 0xdd787ca3f50, count: -18 ddb{1}> show registers rdi 0xffffffff81e155e8 kprintf_mutex rsi 0xffffffff8140a2c9 db_enter+0x9 rbp 0xffff800021186c70 rbx 0xffff800021186d10 rdx 0xffff800000ad7000 rcx 0x3d6d __ALIGN_SIZE+0x2d6d rax 0xffff800000ad7000 r8 0xffff800021186c40 r9 0x8080808080808080 r10 0x7af848c34388b177 r11 0xffffffff81907030 copy_fault r12 0x3000000008 r13 0xffff800021186c80 r14 0x100 r15 0xffffffff81b7dbf1 cmd0646_9_tim_udma+0x1d277 rip 0xffffffff8140a2ca db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff800021186c70 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor1) pid=283521 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=64, nice=20 forw=0x0, list=0xffff8000210a3c38,0xffff8000210a3540 process=0xffff8000210e72d8 user=0xffff800021182000, vmspace=0xffffff00658f3d70 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND * 969 283521 69627 65534 3 0x4003010 suspend syz-executor1 969 89951 69627 65534 2 0x4081090 syz-executor1 86498 82728 87343 65534 2 0x10 syz-executor0 86498 451868 87343 65534 2 0x4000010 syz-executor0 86498 213428 87343 65534 3 0x4000090 fsleep syz-executor0 87343 416604 7028 65534 3 0x90 nanosleep syz-executor0 7028 303714 52014 0 3 0x82 wait syz-executor0 69627 376067 8248 65534 3 0x90 nanosleep syz-executor1 8248 505754 52014 0 3 0x82 wait syz-executor1 75450 389971 0 0 3 0x14200 bored sosplice 52014 502257 26327 0 3 0x82 kqread syz-fuzzer 52014 355129 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 74875 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 40333 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 400380 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 177289 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 440099 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 404945 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 231763 26327 0 3 0x4000082 thrsleep syz-fuzzer 52014 85210 26327 0 3 0x4000082 thrsleep syz-fuzzer 26327 253033 19942 0 3 0x10008a pause ksh 19942 439160 70635 0 3 0x92 select sshd 41282 381892 1 0 3 0x100083 ttyin getty 70635 452628 1 0 3 0x80 select sshd 95570 398447 90893 73 3 0x100090 kqread syslogd 90893 301016 1 0 3 0x100082 netio syslogd 58152 497188 1 77 3 0x100090 poll dhclient 6286 480291 1 0 3 0x80 poll dhclient 89619 368541 0 0 2 0x14200 zerothread 25070 187929 0 0 3 0x14200 aiodoned aiodoned 37367 174835 0 0 3 0x14200 syncer update 27434 358692 0 0 3 0x14200 cleaner cleaner 85011 422080 0 0 3 0x14200 reaper reaper 96267 226435 0 0 3 0x14200 pgdaemon pagedaemon 67979 231509 0 0 3 0x14200 bored crynlk 18410 368794 0 0 3 0x14200 bored crypto 39932 181324 0 0 3 0x40014200 acpi0 acpi0 78242 212852 0 0 3 0x40014200 idle1 11843 477151 0 0 3 0x14200 bored softnet 16299 333626 0 0 3 0x14200 bored systqmp 50005 51823 0 0 3 0x14200 bored systq 40528 186863 0 0 3 0x40014200 bored softclock 65161 67452 0 0 3 0x40014200 idle0 1 378416 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper