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(ffffffff81487d04,ffff8000211e9390,ffff80002109d2d8,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff80002109d2d8,ffff8000211e4000) 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,ffff8000042db000,ffffffffffffffff,0,9,ffff80002109d2d8) at alltraps_kern+0x7b ptsignal(2764,ffff80002109d2d8,ffff8000210cafe0) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211e9620) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211e9620,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211e9620,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff80002109d2d8,3,0,ffff8000210cb0a8) at tsleep+0x142 single_thread_set(ffff80002109d2d8,ffff80002109d2d8,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff80002109d2d8,ffff80002109d2d8,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff80002109d2d8,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211e97f0, 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(ffffffff81487d04,ffff8000211e9390,ffff80002109d2d8,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff80002109d2d8,ffff8000211e4000) 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,ffff8000042db000,ffffffffffffffff,0,9,ffff80002109d2d8) at alltraps_kern+0x7b ptsignal(2764,ffff80002109d2d8,ffff8000210cafe0) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211e9620) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211e9620,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211e9620,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff80002109d2d8,3,0,ffff8000210cb0a8) at tsleep+0x142 single_thread_set(ffff80002109d2d8,ffff80002109d2d8,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff80002109d2d8,ffff80002109d2d8,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff80002109d2d8,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff80002109d2d8) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff80002109d2d8) 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,f9c8abf2000,53,0,f9bf9a882a0) at Xsyscall+0x128 end of kernel end trace frame: 0xf9c48ff50e0, count: -18 ddb{1}> show registers rdi 0xffffffff81e28590 kprintf_mutex rsi 0xffffffff815b4b89 db_enter+0x9 rbp 0xffff8000211e92f0 rbx 0xffff8000211e9390 rdx 0xffff8000042db000 rcx 0x3ec2 __ALIGN_SIZE+0x2ec2 rax 0xffff8000042db000 r8 0xffff8000211e92c0 r9 0x8080808080808080 r10 0x8dcaeeda2fa6c1be r11 0xffffffff81349670 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211e9300 r14 0x100 r15 0xffffffff81bf5a22 cmd0646_9_tim_udma+0x1f0e5 rip 0xffffffff815b4b8a db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff8000211e92f0 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor0) pid=493376 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff80002109c720,0xffffffff81ee7e68 process=0xffff8000210cafe0 user=0xffff8000211e4000, vmspace=0xffffff007bd89958 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 15868 303473 40289 65534 2 0x4081090 syz-executor0 *15868 493376 40289 65534 3 0x4003010 suspend syz-executor0 43117 497408 15813 65534 3 0x90 nanosleep syz-executor1 43117 425127 15813 65534 3 0x4000090 nanosleep syz-executor1 43117 398872 15813 65534 3 0x4000090 fsleep syz-executor1 40289 133019 56794 65534 3 0x90 nanosleep syz-executor0 56794 465320 33408 0 3 0x82 wait syz-executor0 15813 23472 28657 65534 3 0x90 nanosleep syz-executor1 28657 135882 33408 0 3 0x82 wait syz-executor1 76511 17875 0 0 3 0x14200 bored sosplice 33408 147878 9011 0 3 0x82 thrsleep syz-fuzzer 33408 503228 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 162075 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 461463 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 107172 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 194035 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 358720 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 140644 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 104060 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 244160 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 172213 9011 0 3 0x4000082 thrsleep syz-fuzzer 33408 393357 9011 0 3 0x4000082 kqread syz-fuzzer 9011 142692 98702 0 3 0x10008a pause ksh 98702 283858 35426 0 3 0x92 select sshd 26601 363526 1 0 3 0x100083 ttyin getty 35426 326673 1 0 3 0x80 select sshd 62453 348063 64664 73 3 0x100090 kqread syslogd 64664 503852 1 0 3 0x100082 netio syslogd 24014 395043 1 77 3 0x100090 poll dhclient 94674 257325 1 0 3 0x80 poll dhclient 47171 255559 0 0 3 0x14200 pgzero zerothread 30752 345531 0 0 3 0x14200 aiodoned aiodoned 2096 481234 0 0 3 0x14200 syncer update 65895 66071 0 0 3 0x14200 cleaner cleaner 77551 264518 0 0 3 0x14200 reaper reaper 83350 277943 0 0 3 0x14200 pgdaemon pagedaemon 38713 212392 0 0 3 0x14200 bored crynlk 3482 49226 0 0 3 0x14200 bored crypto 54376 380222 0 0 3 0x40014200 acpi0 acpi0 51710 273096 0 0 3 0x40014200 idle1 87178 241532 0 0 3 0x14200 bored softnet 14453 138632 0 0 3 0x14200 bored systqmp 57242 97713 0 0 3 0x14200 bored systq 63455 76833 0 0 3 0x40014200 bored softclock 42649 105107 0 0 3 0x40014200 idle0 1 401086 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper