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(ffffffff81603364,ffff8000211c74a0,ffff8000210844b8,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210844b8,ffff8000211c2000) 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,ffff8000018d7000,ffffffffffffffff,0,9,ffff8000210844b8) at alltraps_kern+0x7b ptsignal(20f6,ffff8000210844b8,ffff8000210b7310) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211c7730) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211c7730,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211c7730,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210844b8,3,0,ffff8000210b73d8) 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: 0xffff8000211c7900, 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(ffffffff81603364,ffff8000211c74a0,ffff8000210844b8,ffff800000038e80) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210844b8,ffff8000211c2000) 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,ffff8000018d7000,ffffffffffffffff,0,9,ffff8000210844b8) at alltraps_kern+0x7b ptsignal(20f6,ffff8000210844b8,ffff8000210b7310) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff8000211c7730) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff8000211c7730,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff8000211c7730,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210844b8,3,0,ffff8000210b73d8) 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(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(6,58,908c3b35600,53,0,908de718aa0) at Xsyscall+0x128 end of kernel end trace frame: 0x908d0df2d70, count: -18 ddb{1}> show registers rdi 0xffffffff81e32f30 kprintf_mutex rsi 0xffffffff819edaf9 db_enter+0x9 rbp 0xffff8000211c7400 rbx 0xffff8000211c74a0 rdx 0xffff8000018d7000 rcx 0x401d __ALIGN_SIZE+0x301d rax 0xffff8000018d7000 r8 0xffff8000211c73d0 r9 0x8080808080808080 r10 0xbdea69b4cd0d96ae r11 0xffffffff810fe130 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff8000211c7410 r14 0x100 r15 0xffffffff81bf37d3 cmd0646_9_tim_udma+0x1f579 rip 0xffffffff819edafa db_enter+0xa cs 0x8 rflags 0x206 rsp 0xffff8000211c7400 ss 0x10 db_enter+0xa: popq %rbp ddb{1}> show proc PROC (syz-executor0) pid=188268 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff800021084e18,0xffffffff81ec3358 process=0xffff8000210b7310 user=0xffff8000211c2000, vmspace=0xffffff00661cdb68 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 93560 352035 58186 65534 2 0x4081090 syz-executor0 *93560 188268 58186 65534 3 0x4003010 suspend syz-executor0 58186 219277 15275 65534 3 0x90 nanosleep syz-executor0 15275 10626 86037 0 3 0x82 wait syz-executor0 45806 445503 65905 65534 3 0x90 nanosleep syz-executor1 65905 275788 86037 0 3 0x82 wait syz-executor1 478 509551 0 0 3 0x14200 bored sosplice 86037 299798 83830 0 3 0x82 thrsleep syz-fuzzer 86037 502132 83830 0 3 0x4000082 thrsleep syz-fuzzer 86037 142346 83830 0 3 0x4000082 thrsleep syz-fuzzer 86037 460579 83830 0 3 0x4000082 thrsleep syz-fuzzer 86037 455758 83830 0 3 0x4000082 thrsleep syz-fuzzer 86037 511230 83830 0 3 0x4000082 thrsleep syz-fuzzer 86037 369963 83830 0 3 0x4000082 thrsleep syz-fuzzer 86037 303631 83830 0 3 0x4000082 thrsleep syz-fuzzer 86037 400896 83830 0 3 0x4000082 kqread syz-fuzzer 86037 57286 83830 0 3 0x4000082 thrsleep syz-fuzzer 83830 71937 39966 0 3 0x10008a pause ksh 39966 148414 90244 0 3 0x92 select sshd 85678 46922 1 0 3 0x100083 ttyin getty 90244 503072 1 0 3 0x80 select sshd 82135 274033 27766 73 3 0x100090 kqread syslogd 27766 375955 1 0 3 0x100082 netio syslogd 99449 271749 1 77 3 0x100090 poll dhclient 7453 398046 1 0 3 0x80 poll dhclient 86525 301183 0 0 3 0x14200 pgzero zerothread 66519 154097 0 0 3 0x14200 aiodoned aiodoned 57115 436786 0 0 3 0x14200 syncer update 84090 307860 0 0 3 0x14200 cleaner cleaner 79919 476855 0 0 3 0x14200 reaper reaper 47846 309774 0 0 3 0x14200 pgdaemon pagedaemon 95564 264900 0 0 3 0x14200 bored crynlk 14908 506781 0 0 3 0x14200 bored crypto 60981 472349 0 0 3 0x40014200 acpi0 acpi0 18037 173883 0 0 3 0x40014200 idle1 80659 293801 0 0 3 0x14200 bored softnet 20101 500712 0 0 3 0x14200 bored systqmp 88239 358604 0 0 3 0x14200 bored systq 57256 437545 0 0 3 0x40014200 bored softclock 97401 433273 0 0 3 0x40014200 idle0 1 441472 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper