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(ffffffff813b6fb4,ffff800021125780,ffff8000210844b8,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210844b8,ffff800021120000) 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(6,4082000,ffffffffffffffff,0,9,ffff800021084008) at alltraps_kern+0x7b ptsignal(25ef,ffff8000210844b8,ffff800021070008) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021125a10) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021125a10,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021125a10,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210844b8,3,0,ffff8000210700d0) at tsleep+0x142 single_thread_set(ffff8000210844b8,ffff8000210844b8,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210844b8,ffff8000210844b8,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff8000210844b8,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff800021125be0, 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(ffffffff813b6fb4,ffff800021125780,ffff8000210844b8,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210844b8,ffff800021120000) 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(6,4082000,ffffffffffffffff,0,9,ffff800021084008) at alltraps_kern+0x7b ptsignal(25ef,ffff8000210844b8,ffff800021070008) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021125a10) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021125a10,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021125a10,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210844b8,3,0,ffff8000210700d0) at tsleep+0x142 single_thread_set(ffff8000210844b8,ffff8000210844b8,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210844b8,ffff8000210844b8,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2030 exit1(ffff8000210844b8,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210844b8) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff8000210844b8) at postsig+0x3ea sys/kern/kern_sig.c:1420 userret(4) 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(0,4,0,5b,8aa50de50f8,8ac9bfb3000) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe4bf0, count: -18 ddb{0}> show registers rdi 0xffffffff81e27fd8 kprintf_mutex rsi 0x5 rbp 0xffff8000211256e0 rbx 0xffff800021125780 rdx 0x3fd rcx 0 rax 0x1 r8 0xffff8000211256b0 r9 0x8080808080808080 r10 0 r11 0xffffffff812b1590 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211256f0 r14 0x100 r15 0xffffffff81bf6fef cmd0646_9_tim_udma+0x1ccc6 rip 0xffffffff8180d0ca db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff8000211256e0 ss 0x10 db_enter+0xa: popq %rbp ddb{0}> show proc PROC (syz-executor5188) pid=278464 stat=sleep flags process=1000 proc=2000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210a4268,0xffff800021084bd0 process=0xffff800021070008 user=0xffff800021120000, vmspace=0xffffff007f125d68 estcpu=36, cpticks=6, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 66853 3188 82214 0 2 0 syz-executor5188 66853 285753 82214 0 2 0x4000000 syz-executor5188 66853 409970 82214 0 2 0x4000000 syz-executor5188 * 2227 278464 22754 0 3 0x3000 suspend syz-executor5188 2227 378103 22754 0 2 0x4081000 syz-executor5188 82214 434144 97786 0 3 0x80 nanosleep syz-executor5188 22754 291231 97786 0 3 0x80 nanosleep syz-executor5188 97786 326636 76596 0 3 0x82 nanosleep syz-executor5188 76596 404328 44335 0 3 0x10008a pause ksh 44335 213151 20627 0 3 0x92 select sshd 48486 317805 1 0 3 0x100083 ttyin getty 20627 454646 1 0 3 0x80 select sshd 24814 143825 21834 73 3 0x100090 kqread syslogd 21834 128170 1 0 3 0x100082 netio syslogd 11078 282038 1 77 3 0x100090 poll dhclient 32570 485575 1 0 3 0x80 poll dhclient 62157 435882 0 0 2 0x14200 zerothread 77651 227550 0 0 3 0x14200 aiodoned aiodoned 33305 442185 0 0 3 0x14200 syncer update 18223 156886 0 0 3 0x14200 cleaner cleaner 32030 317104 0 0 3 0x14200 reaper reaper 12306 73830 0 0 3 0x14200 pgdaemon pagedaemon 85352 70320 0 0 3 0x14200 bored crynlk 88717 35408 0 0 3 0x14200 bored crypto 72092 404617 0 0 3 0x40014200 acpi0 acpi0 36610 288976 0 0 3 0x40014200 idle1 77393 268240 0 0 3 0x14200 bored softnet 45317 512453 0 0 3 0x14200 bored systqmp 97032 238928 0 0 3 0x14200 bored systq 95893 166655 0 0 3 0x40014200 bored softclock 55700 432381 0 0 3 0x40014200 idle0 1 444557 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper