login: panic: kernel diagnostic assertion "__mp_lock_held(&sched_lock, curcpu()) == 0" failed: file "/syzkaller/managers/multicore/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(ffffffff81609d74,ffff80002119f6f0,ffff8000210b6be0,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210b6be0,ffff80002119a000) 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(6,0,ffffffffffffffff,0,9,ffff8000210b72e8) at alltraps_kern+0x7b ptsignal(4349,ffff8000210b6be0,ffff8000210a6010) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff80002119f980) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff80002119f980,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff80002119f980,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a6010,ffff8000210b6be0,0,ffff8000210a6030) at tsleep+0x142 exit1(ffff8000210b6be0,0,0) at exit1+0x17b sys/kern/kern_exit.c:166 single_thread_check(ffff8000210b6be0,3) at single_thread_check+0xd6 sys/kern/kern_sig.c:1925 end trace frame: 0xffff80002119faa0, 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/multicore/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(ffffffff81609d74,ffff80002119f6f0,ffff8000210b6be0,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210b6be0,ffff80002119a000) 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(6,0,ffffffffffffffff,0,9,ffff8000210b72e8) at alltraps_kern+0x7b ptsignal(4349,ffff8000210b6be0,ffff8000210a6010) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff80002119f980) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff80002119f980,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff80002119f980,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a6010,ffff8000210b6be0,0,ffff8000210a6030) at tsleep+0x142 exit1(ffff8000210b6be0,0,0) at exit1+0x17b sys/kern/kern_exit.c:166 single_thread_check(ffff8000210b6be0,3) at single_thread_check+0xd6 sys/kern/kern_sig.c:1925 single_thread_set(ffff8000210b6be0,ffff8000210b6be0,0) at single_thread_set+0x36 sys/kern/kern_sig.c:1955 exit1(ffff8000210b6be0,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210b6be0) at postsig+0x408 sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff8000210b6be0) at postsig+0x408 sys/kern/kern_sig.c:1420 userret(5b0) at userret+0x11b sys/kern/kern_sig.c:1870 syscall(0) at syscall+0x52f mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(0) at syscall+0x52f sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,4,bf9a831ac90,5b,54490,bfbd17b6000) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4910, count: -20 ddb{1}> show registers rdi 0xffffffff81e2a6f8 kprintf_mutex rsi 0x5 rbp 0xffff80002119f650 rbx 0xffff80002119f6f0 rdx 0x3fd rcx 0 rax 0 r8 0xffff80002119f620 r9 0x8080808080808080 r10 0 r11 0xffffffff8167c2b0 copy_fault r12 0x3000000008 r13 0xffff80002119f660 r14 0x100 r15 0xffffffff81b7f7d9 cmd0646_9_tim_udma+0x20575 rip 0xffffffff81a8981a db_enter+0xa cs 0x8 rflags 0x246 rsp 0xffff80002119f650 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor1) pid=343287 stat=sleep flags process=1000 proc=82000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210b7798,0xffff8000210b72f8 process=0xffff8000210a6010 user=0xffff80002119a000, vmspace=0xffffff007f124c60 estcpu=36, cpticks=21, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 29970 183707 96361 0 2 0x4081080 syz-executor1 29970 291267 96361 0 2 0x4081080 syz-executor1 29970 394677 96361 0 2 0x4081080 syz-executor1 29970 336161 96361 0 3 0x4003000 suspend syz-executor1 89119 107518 29263 0 3 0x80 nanosleep syz-executor0 89119 257666 29263 0 3 0x4000080 lockf syz-executor0 89119 225473 29263 0 3 0x4000080 lockf syz-executor0 89119 274057 29263 0 3 0x4000080 lockf syz-executor0 89119 416115 29263 0 3 0x4000080 fsleep syz-executor0 96361 277922 34369 0 3 0x82 nanosleep syz-executor1 29263 7388 34369 0 3 0x82 nanosleep syz-executor0 34369 477236 52182 0 3 0x82 thrsleep syz-fuzzer 34369 79880 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 422683 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 133511 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 405180 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 141885 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 213033 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 68481 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 225082 52182 0 3 0x4000082 thrsleep syz-fuzzer 34369 351254 52182 0 3 0x4000082 kqread syz-fuzzer 52182 187116 66629 0 3 0x10008a pause ksh 66629 57831 32111 0 3 0x92 select sshd 75915 34813 1 0 3 0x100083 ttyin getty 32111 73309 1 0 3 0x80 select sshd 55222 231503 18011 73 3 0x100090 kqread syslogd 18011 57628 1 0 3 0x100082 netio syslogd 75897 489262 1 77 3 0x100090 poll dhclient 63449 284341 1 0 3 0x80 poll dhclient 69636 267699 0 0 3 0x14200 pgzero zerothread 52048 191771 0 0 3 0x14200 aiodoned aiodoned 48454 83566 0 0 3 0x14200 syncer update 95662 153763 0 0 3 0x14200 cleaner cleaner 65523 44458 0 0 3 0x14200 reaper reaper 85135 49968 0 0 3 0x14200 pgdaemon pagedaemon 38521 455681 0 0 3 0x14200 bored crynlk 27491 359767 0 0 3 0x14200 bored crypto 74203 61596 0 0 3 0x40014200 acpi0 acpi0 64844 335988 0 0 3 0x40014200 idle1 83987 132423 0 0 3 0x14200 bored softnet 83546 484575 0 0 3 0x14200 bored systqmp 79100 328554 0 0 3 0x14200 bored systq 42689 265231 0 0 3 0x40014200 bored softclock 66914 362861 0 0 3 0x40014200 idle0 1 279543 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper