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(ffffffff81816b64,ffff80002119ab50,ffff8000210a3c38,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3c38,ffff800021196000) 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,ffff8000016d7000,ffffffffffffffff,0,9,ffff8000210a3c38) at alltraps_kern+0x7b ptsignal(22a3,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,ffff80002119ade0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff80002119ade0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff80002119ade0,32) 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: 0xffff80002119afb0, 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(ffffffff81816b64,ffff80002119ab50,ffff8000210a3c38,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3c38,ffff800021196000) 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,ffff8000016d7000,ffffffffffffffff,0,9,ffff8000210a3c38) at alltraps_kern+0x7b ptsignal(22a3,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,ffff80002119ade0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff80002119ade0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff80002119ade0,32) 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(6,58,884a14f0800,53,0,884387a3740) at Xsyscall+0x128 end of kernel end trace frame: 0x8843bc0c320, count: -18 ddb{0}> show registers rdi 0xffffffff81e467e0 kprintf_mutex rsi 0xffffffff81224279 db_enter+0x9 rbp 0xffff80002119aab0 rbx 0xffff80002119ab50 rdx 0xffff8000016d7000 rcx 0x497d __ALIGN_SIZE+0x397d rax 0xffff8000016d7000 r8 0xffff80002119aa80 r9 0x8080808080808080 r10 0xec9793983816d6a2 r11 0xffffffff81a4e5a0 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff80002119aac0 r14 0x100 r15 0xffffffff81bf3dec cmd0646_9_tim_udma+0x205cb rip 0xffffffff8122427a db_enter+0xa cs 0x8 rflags 0x206 rsp 0xffff80002119aab0 ss 0x10 db_enter+0xa: popq %rbp ddb{0}> show proc PROC (syz-executor1) pid=474756 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210a32d8,0xffff8000210a3540 process=0xffff8000210b6fe0 user=0xffff800021196000, vmspace=0xffffff0067f2ab68 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 74939 185928 75122 65534 3 0x90 nanosleep syz-executor0 74939 185634 75122 65534 3 0x4000090 fsleep syz-executor0 74939 141283 75122 65534 3 0x4000090 fsleep syz-executor0 75735 350247 97571 65534 2 0x4081090 syz-executor1 *75735 474756 97571 65534 3 0x4003010 suspend syz-executor1 75122 290464 93405 65534 3 0x90 nanosleep syz-executor0 93405 115566 11085 0 3 0x82 wait syz-executor0 97571 27316 87147 65534 3 0x90 nanosleep syz-executor1 87147 93427 11085 0 3 0x82 wait syz-executor1 94088 42108 0 0 3 0x14200 bored sosplice 11085 340274 66867 0 3 0x82 thrsleep syz-fuzzer 11085 17806 66867 0 3 0x4000082 thrsleep syz-fuzzer 11085 316935 66867 0 3 0x4000082 thrsleep syz-fuzzer 11085 80501 66867 0 3 0x4000082 thrsleep syz-fuzzer 11085 385902 66867 0 3 0x4000082 thrsleep syz-fuzzer 11085 298980 66867 0 3 0x4000082 thrsleep syz-fuzzer 11085 40444 66867 0 3 0x4000082 thrsleep syz-fuzzer 11085 434095 66867 0 3 0x4000082 thrsleep syz-fuzzer 11085 112255 66867 0 3 0x4000082 kqread syz-fuzzer 11085 346340 66867 0 3 0x4000082 thrsleep syz-fuzzer 66867 510557 75 0 3 0x10008a pause ksh 75 38967 51212 0 3 0x92 select sshd 75756 358008 1 0 3 0x100083 ttyin getty 51212 97639 1 0 3 0x80 select sshd 8993 183567 8646 73 3 0x100090 kqread syslogd 8646 415726 1 0 3 0x100082 netio syslogd 74470 27612 1 77 3 0x100090 poll dhclient 10564 137561 1 0 3 0x80 poll dhclient 4633 443069 0 0 2 0x14200 zerothread 46427 179936 0 0 3 0x14200 aiodoned aiodoned 67013 412220 0 0 3 0x14200 syncer update 85897 207341 0 0 3 0x14200 cleaner cleaner 43376 239654 0 0 3 0x14200 reaper reaper 6348 187230 0 0 3 0x14200 pgdaemon pagedaemon 51134 519895 0 0 3 0x14200 bored crynlk 39584 36848 0 0 3 0x14200 bored crypto 86859 306706 0 0 3 0x40014200 acpi0 acpi0 92642 153367 0 0 3 0x40014200 idle1 41153 144797 0 0 3 0x14200 bored softnet 39317 57309 0 0 3 0x14200 bored systqmp 79725 241665 0 0 3 0x14200 bored systq 25991 104918 0 0 3 0x40014200 bored softclock 75150 422967 0 0 3 0x40014200 idle0 1 194016 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper