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(ffffffff8111c7f4,ffff800021152c80,ffff8000210a3080,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3080,ffff80002114e000) 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,ffff800000cd7000,ffffffffffffffff,0,9,ffff8000210a3080) at alltraps_kern+0x7b ptsignal(1cad,ffff8000210a3080,ffff8000210b6cb8) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021152f10) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021152f10,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021152f10,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a3080,3,0,ffff8000210b6d80) at tsleep+0x142 single_thread_set(ffff8000210a3080,ffff8000210a3080,0) at single_thread_set+0x26b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210a3080,ffff8000210a3080,0) at single_thread_set+0x26b sys/kern/kern_sig.c:2030 exit1(ffff8000210a3080,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 end trace frame: 0xffff8000211530e0, 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(ffffffff8111c7f4,ffff800021152c80,ffff8000210a3080,ffff80000002f180) at __assert+0x24 sys/kern/subr_prf.c:155 _kernel_lock(ffff8000210a3080,ffff80002114e000) 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,ffff800000cd7000,ffffffffffffffff,0,9,ffff8000210a3080) at alltraps_kern+0x7b ptsignal(1cad,ffff8000210a3080,ffff8000210b6cb8) at ptsignal+0x115 sys/kern/kern_sig.c:932 mi_switch() at mi_switch+0x1fb sys/kern/sched_bsd.c:392 sleep_finish(1,ffff800021152f10) at sleep_finish+0xd3 sys/kern/kern_synch.c:312 sleep_finish_all(ffff800021152f10,32) at sleep_finish_all+0x22 sleep_finish_timeout sys/kern/kern_synch.c:336 [inline] sleep_finish_all(ffff800021152f10,32) at sleep_finish_all+0x22 sys/kern/kern_synch.c:157 tsleep(ffff8000210a3080,3,0,ffff8000210b6d80) at tsleep+0x142 single_thread_set(ffff8000210a3080,ffff8000210a3080,0) at single_thread_set+0x26b single_thread_wait sys/kern/kern_sig.c:2039 [inline] single_thread_set(ffff8000210a3080,ffff8000210a3080,0) at single_thread_set+0x26b sys/kern/kern_sig.c:2030 exit1(ffff8000210a3080,9,0) at exit1+0x84 sys/kern/kern_exit.c:137 postsig(100,ffff8000210a3080) at postsig+0x408 sigexit sys/kern/kern_sig.c:1488 [inline] postsig(100,ffff8000210a3080) at postsig+0x408 sys/kern/kern_sig.c:1420 userret(530) 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(6,58,f220e51ac00,53,0,f21d073b640) at Xsyscall+0x128 end of kernel end trace frame: 0xf228ee536f0, count: -18 ddb{0}> show registers rdi 0xffffffff81e08fc0 kprintf_mutex rsi 0xffffffff812c1619 db_enter+0x9 rbp 0xffff800021152be0 rbx 0xffff800021152c80 rdx 0xffff800000cd7000 rcx 0x3e9e __ALIGN_SIZE+0x2e9e rax 0xffff800000cd7000 r8 0xffff800021152bb0 r9 0x8080808080808080 r10 0x7c36d301dc82559b r11 0xffffffff81b2b680 copy_fault r12 0x3000000008 r13 0xffff800021152bf0 r14 0x100 r15 0xffffffff81b7e6a6 cmd0646_9_tim_udma+0x1c34e rip 0xffffffff812c161a db_enter+0xa cs 0x8 rflags 0x202 rsp 0xffff800021152be0 ss 0x10 db_enter+0xa: popq %rbp ddb{0}> show proc PROC (syz-executor1) pid=145909 stat=sleep flags process=1010 proc=4002000 pri=50, usrpri=86, nice=20 forw=0x0, list=0xffff8000210a2978,0xffffffff81eade68 process=0xffff8000210b6cb8 user=0xffff80002114e000, vmspace=0xffffff00659f0320 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 64102 465659 31293 65534 2 0x4081090 syz-executor1 *64102 145909 31293 65534 3 0x4003010 suspend syz-executor1 40390 425474 70323 65534 3 0x90 nanosleep syz-executor0 70323 523213 32738 0 3 0x82 wait syz-executor0 31293 441916 99520 65534 3 0x90 nanosleep syz-executor1 99520 119659 32738 0 3 0x82 wait syz-executor1 35060 480157 0 0 3 0x14200 bored sosplice 32738 138311 49913 0 3 0x82 thrsleep syz-fuzzer 32738 397974 49913 0 3 0x4000082 thrsleep syz-fuzzer 32738 489360 49913 0 3 0x4000082 thrsleep syz-fuzzer 32738 243785 49913 0 3 0x4000082 thrsleep syz-fuzzer 32738 356148 49913 0 3 0x4000082 thrsleep syz-fuzzer 32738 192582 49913 0 3 0x4000082 thrsleep syz-fuzzer 32738 401979 49913 0 3 0x4000082 thrsleep syz-fuzzer 32738 154026 49913 0 3 0x4000082 kqread syz-fuzzer 32738 519142 49913 0 3 0x4000082 thrsleep syz-fuzzer 32738 136596 49913 0 3 0x4000082 thrsleep syz-fuzzer 49913 379308 93646 0 3 0x10008a pause ksh 93646 415636 7943 0 3 0x92 select sshd 26620 474088 1 0 3 0x100083 ttyin getty 7943 192814 1 0 3 0x80 select sshd 99092 269798 516 73 3 0x100090 kqread syslogd 516 505105 1 0 3 0x100082 netio syslogd 93870 420727 1 77 3 0x100090 poll dhclient 38042 116796 1 0 3 0x80 poll dhclient 6067 229570 0 0 3 0x14200 pgzero zerothread 94701 205999 0 0 3 0x14200 aiodoned aiodoned 16714 439334 0 0 3 0x14200 syncer update 60029 423354 0 0 3 0x14200 cleaner cleaner 7349 94813 0 0 3 0x14200 reaper reaper 3237 175785 0 0 3 0x14200 pgdaemon pagedaemon 57471 214782 0 0 3 0x14200 bored crynlk 74214 440257 0 0 3 0x14200 bored crypto 10498 116919 0 0 3 0x40014200 acpi0 acpi0 46978 193224 0 0 3 0x40014200 idle1 81362 302763 0 0 3 0x14200 bored softnet 27710 338131 0 0 3 0x14200 bored systqmp 49125 146023 0 0 3 0x14200 bored systq 67428 90712 0 0 3 0x40014200 bored softclock 8843 377578 0 0 3 0x40014200 idle0 1 411553 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper