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,ffff800021195100,ffff8000210a2bd0,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2bd0,ffff800021190000) 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,ffff8000012d6000,ffffffffffffffff,0,9,ffff8000210a2bd0) at alltraps_kern+0x7b ptsignal(2ad7,ffff8000210a2bd0,ffff8000210b7c80) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021195390) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021195390,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021195390,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2bd0,3,0,ffff8000210b7d48) at tsleep+0x142 single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a2bd0,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff800021195560, 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,ffff800021195100,ffff8000210a2bd0,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2bd0,ffff800021190000) 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,ffff8000012d6000,ffffffffffffffff,0,9,ffff8000210a2bd0) at alltraps_kern+0x7b ptsignal(2ad7,ffff8000210a2bd0,ffff8000210b7c80) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021195390) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021195390,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021195390,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2bd0,3,0,ffff8000210b7d48) at tsleep+0x142 single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a2bd0,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210a2bd0) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1500 [inline] postsig(100,ffff8000210a2bd0) 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(6,58,9b35f792e00,53,0,9b35f78a120) at Xsyscall+0x128 end of kernel end trace frame: 0x9b3f91573d0, count: -18 ddb{1}> show registers rdi 0xffffffff81e337f8 kprintf_mutex rsi 0xffffffff81696879 db_enter+0x9 rbp 0xffff800021195060 rbx 0xffff800021195100 rdx 0xffff8000012d6000 rcx 0x4365 __ALIGN_SIZE+0x3365 rax 0xffff8000012d6000 r8 0xffff800021195030 r9 0x8080808080808080 r10 0x2f4d9a4f53f45392 r11 0xffffffff8181f470 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff800021195070 r14 0x100 r15 0xffffffff81bf4e1e cmd0646_9_tim_udma+0x1f12c rip 0xffffffff8169687a db_enter+0xa cs 0x8 rflags 0x206 rsp 0xffff800021195060 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor0) pid=129412 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210a3788,0xffffffff81eb7cb0 process=0xffff8000210b7c80 user=0xffff800021190000, vmspace=0xffffff0065b44218 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 89569 495286 22088 65534 2 0x10 syz-executor1 89569 490884 22088 65534 3 0x4000010 biowait syz-executor1 29314 368648 73783 65534 2 0x4081090 syz-executor0 *29314 129412 73783 65534 3 0x4003010 suspend syz-executor0 73783 340175 91609 65534 3 0x90 nanosleep syz-executor0 91609 34100 11668 0 3 0x82 wait syz-executor0 22088 96562 99615 65534 3 0x90 nanosleep syz-executor1 99615 119208 11668 0 3 0x82 wait syz-executor1 56369 396918 0 0 3 0x14200 bored sosplice 11668 232044 24130 0 3 0x82 thrsleep syz-fuzzer 11668 473878 24130 0 3 0x4000082 nanosleep syz-fuzzer 11668 163579 24130 0 3 0x4000082 thrsleep syz-fuzzer 11668 162965 24130 0 3 0x4000082 thrsleep syz-fuzzer 11668 206450 24130 0 3 0x4000082 thrsleep syz-fuzzer 11668 177793 24130 0 3 0x4000082 thrsleep syz-fuzzer 11668 89396 24130 0 3 0x4000082 thrsleep syz-fuzzer 11668 140038 24130 0 3 0x4000082 kqread syz-fuzzer 11668 205861 24130 0 3 0x4000082 thrsleep syz-fuzzer 11668 169042 24130 0 3 0x4000082 thrsleep syz-fuzzer 24130 465676 86435 0 3 0x10008a pause ksh 86435 121707 35644 0 3 0x92 select sshd 37851 428331 1 0 3 0x100083 ttyin getty 35644 95552 1 0 3 0x80 select sshd 99954 322634 19771 73 3 0x100090 kqread syslogd 19771 39107 1 0 3 0x100082 netio syslogd 60411 134578 1 77 3 0x100090 poll dhclient 21997 347033 1 0 3 0x80 poll dhclient 58094 421103 0 0 2 0x14200 zerothread 78879 54068 0 0 3 0x14200 aiodoned aiodoned 15990 337320 0 0 3 0x14200 syncer update 50449 25705 0 0 3 0x14200 cleaner cleaner 26041 214232 0 0 3 0x14200 reaper reaper 13064 81087 0 0 3 0x14200 pgdaemon pagedaemon 48197 478893 0 0 3 0x14200 bored crynlk 23910 301710 0 0 3 0x14200 bored crypto 54426 464120 0 0 3 0x40014200 acpi0 acpi0 25241 132489 0 0 3 0x40014200 idle1 4976 275881 0 0 3 0x14200 bored softnet 9458 477404 0 0 3 0x14200 bored systqmp 99508 375635 0 0 3 0x14200 bored systq 73165 14544 0 0 3 0x40014200 bored softclock 38014 508816 0 0 3 0x40014200 idle0 1 125227 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper