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,ffff8000211db560,ffff8000210a2bd0,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2bd0,ffff8000211d6000) 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,ffff800002edd000,ffffffffffffffff,0,9,ffff8000210a2bd0) at alltraps_kern+0x7b ptsignal(1de2,ffff8000210a2bd0,ffff8000210b7958) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211db7f0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211db7f0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211db7f0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2bd0,3,0,ffff8000210b7a20) at tsleep+0x142 single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a2bd0,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211db9c0, 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,ffff8000211db560,ffff8000210a2bd0,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a2bd0,ffff8000211d6000) 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,ffff800002edd000,ffffffffffffffff,0,9,ffff8000210a2bd0) at alltraps_kern+0x7b ptsignal(1de2,ffff8000210a2bd0,ffff8000210b7958) at ptsignal+0x115 sys/kern/kern_sig.c:944 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211db7f0) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211db7f0,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211db7f0,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a2bd0,3,0,ffff8000210b7a20) at tsleep+0x142 single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b single_thread_wait sys/kern/kern_sig.c:2051 [inline] single_thread_set(ffff8000210a2bd0,ffff8000210a2bd0,0) at single_thread_set+0x28b sys/kern/kern_sig.c:2042 exit1(ffff8000210a2bd0,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210a2bd0) at postsig+0x3ea sigexit sys/kern/kern_sig.c:1500 [inline] postsig(100,ffff8000210a2bd0) 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,bb5c9ce0c00,53,0,bb557f4a7e0) at Xsyscall+0x128 end of kernel end trace frame: 0xbb5de5ba320, count: -18 ddb{1}> show registers rdi 0xffffffff81e337f8 kprintf_mutex rsi 0xffffffff81696879 db_enter+0x9 rbp 0xffff8000211db4c0 rbx 0xffff8000211db560 rdx 0xffff800002edd000 rcx 0x468e __ALIGN_SIZE+0x368e rax 0xffff800002edd000 r8 0xffff8000211db490 r9 0x8080808080808080 r10 0xcda75dcf83e71f9e r11 0xffffffff8181f470 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211db4d0 r14 0x100 r15 0xffffffff81bf4e1e cmd0646_9_tim_udma+0x1f12c rip 0xffffffff8169687a db_enter+0xa cs 0x8 rflags 0x206 rsp 0xffff8000211db4c0 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor1) pid=20747 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210a24c8,0xffffffff81eb7cb0 process=0xffff8000210b7958 user=0xffff8000211d6000, vmspace=0xffffff0065afac68 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 14080 263943 76414 65534 2 0x10 syz-executor0 14080 429944 76414 65534 2 0x4000010 syz-executor0 66600 102027 33226 65534 2 0x4081090 syz-executor1 *66600 20747 33226 65534 3 0x4003010 suspend syz-executor1 76414 295567 874 65534 3 0x90 nanosleep syz-executor0 874 239354 7367 0 3 0x82 wait syz-executor0 33226 61950 61070 65534 3 0x90 nanosleep syz-executor1 61070 498841 7367 0 3 0x82 wait syz-executor1 5409 327886 0 0 3 0x14200 bored sosplice 7367 246724 41522 0 3 0x82 thrsleep syz-fuzzer 7367 392736 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 474480 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 444157 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 333926 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 445510 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 180541 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 210017 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 401913 41522 0 3 0x4000082 thrsleep syz-fuzzer 7367 457113 41522 0 3 0x4000082 kqread syz-fuzzer 7367 238142 41522 0 3 0x4000082 thrsleep syz-fuzzer 41522 127701 15440 0 3 0x10008a pause ksh 15440 446843 34850 0 3 0x92 select sshd 86173 274034 1 0 3 0x100083 ttyin getty 34850 251594 1 0 3 0x80 select sshd 47447 211651 60340 73 3 0x100090 kqread syslogd 60340 522663 1 0 3 0x100082 netio syslogd 43234 166703 1 77 3 0x100090 poll dhclient 59776 121306 1 0 3 0x80 poll dhclient 52124 37246 0 0 2 0x14200 zerothread 45761 416156 0 0 3 0x14200 aiodoned aiodoned 35772 203533 0 0 3 0x14200 syncer update 98640 465471 0 0 3 0x14200 cleaner cleaner 84889 409043 0 0 3 0x14200 reaper reaper 67379 389429 0 0 3 0x14200 pgdaemon pagedaemon 40714 519334 0 0 3 0x14200 bored crynlk 87949 235170 0 0 3 0x14200 bored crypto 13356 50278 0 0 3 0x40014200 acpi0 acpi0 74094 416080 0 0 3 0x40014200 idle1 47019 495451 0 0 3 0x14200 bored softnet 31718 241933 0 0 3 0x14200 bored systqmp 35481 282173 0 0 3 0x14200 bored systq 9971 97582 0 0 3 0x40014200 bored softclock 20418 491324 0 0 3 0x40014200 idle0 1 142411 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper