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,ffff8000211dcdc0,ffff8000210a3c38,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3c38,ffff8000211d8000) 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,ffff800000cd6000,ffffffffffffffff,0,9,ffff8000210a3c38) at alltraps_kern+0x7b ptsignal(17f2,ffff8000210a3c38,ffff8000210b6fe0) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211dd050) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211dd050,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211dd050,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a3c38,3,0,ffff8000210b70a8) at tsleep+0x142 single_thread_set(ffff8000210a3c38,ffff8000210a3c38,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a3c38,ffff8000210a3c38,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a3c38,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211dd220, 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,ffff8000211dcdc0,ffff8000210a3c38,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3c38,ffff8000211d8000) 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,ffff800000cd6000,ffffffffffffffff,0,9,ffff8000210a3c38) at alltraps_kern+0x7b ptsignal(17f2,ffff8000210a3c38,ffff8000210b6fe0) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211dd050) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211dd050,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211dd050,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a3c38,3,0,ffff8000210b70a8) at tsleep+0x142 single_thread_set(ffff8000210a3c38,ffff8000210a3c38,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a3c38,ffff8000210a3c38,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a3c38,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210a3c38) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1500 [inline] postsig(100,ffff8000210a3c38) 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,adfc700a800,53,0,adfc7005c60) at Xsyscall+0x128 end of kernel end trace frame: 0xae0a8ea32f0, count: -18 ddb{1}> show registers rdi 0xffffffff81e337f8 kprintf_mutex rsi 0xffffffff81696879 db_enter+0x9 rbp 0xffff8000211dcd20 rbx 0xffff8000211dcdc0 rdx 0xffff800000cd6000 rcx 0x4551 __ALIGN_SIZE+0x3551 rax 0xffff800000cd6000 r8 0xffff8000211dccf0 r9 0x8080808080808080 r10 0xf8ff344a6c0b0d9e r11 0xffffffff8181f470 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211dcd30 r14 0x100 r15 0xffffffff81bf4e1e cmd0646_9_tim_udma+0x1f12c rip 0xffffffff8169687a db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff8000211dcd20 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor1) pid=153736 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=85, nice=20 forw=0x0, list=0xffff8000210a3080,0xffffffff81eb7cb0 process=0xffff8000210b6fe0 user=0xffff8000211d8000, vmspace=0xffffff0065b20d70 estcpu=35, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 6998 4314 75093 65534 3 0x4081010 biowait syz-executor1 * 6998 153736 75093 65534 3 0x4003010 suspend syz-executor1 71439 144205 65303 65534 3 0x90 nanosleep syz-executor0 71439 230265 65303 65534 3 0x4000090 msgwait syz-executor0 71439 427371 65303 65534 3 0x4000090 fsleep syz-executor0 75093 95896 19099 65534 3 0x90 nanosleep syz-executor1 19099 56571 89418 0 3 0x82 wait syz-executor1 65303 34218 6563 65534 3 0x90 nanosleep syz-executor0 6563 501517 89418 0 3 0x82 wait syz-executor0 67806 461236 0 0 3 0x14200 bored sosplice 89418 373376 73059 0 3 0x82 kqread syz-fuzzer 89418 30457 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 413849 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 25906 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 384226 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 475729 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 507282 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 169869 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 362946 73059 0 3 0x4000082 thrsleep syz-fuzzer 89418 240319 73059 0 3 0x4000082 thrsleep syz-fuzzer 73059 17107 29485 0 3 0x10008a pause ksh 29485 167226 69780 0 3 0x92 select sshd 73702 58158 1 0 3 0x100083 ttyin getty 69780 455571 1 0 3 0x80 select sshd 36195 439689 2111 73 3 0x100090 kqread syslogd 2111 242876 1 0 3 0x100082 netio syslogd 30518 376661 1 77 3 0x100090 poll dhclient 47675 109853 1 0 3 0x80 poll dhclient 38659 359853 0 0 3 0x14200 pgzero zerothread 49073 197696 0 0 3 0x14200 aiodoned aiodoned 57713 405326 0 0 3 0x14200 syncer update 97197 520568 0 0 3 0x14200 cleaner cleaner 40054 355233 0 0 3 0x14200 reaper reaper 99888 41939 0 0 3 0x14200 pgdaemon pagedaemon 26296 94855 0 0 3 0x14200 bored crynlk 24674 308675 0 0 3 0x14200 bored crypto 49431 492890 0 0 3 0x40014200 acpi0 acpi0 58148 227876 0 0 3 0x40014200 idle1 41655 413874 0 0 3 0x14200 bored softnet 62191 18169 0 0 3 0x14200 bored systqmp 32068 279528 0 0 3 0x14200 bored systq 19132 92515 0 0 3 0x40014200 bored softclock 41965 15049 0 0 3 0x40014200 idle0 1 358297 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper