rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15069/1:b..l rcu: (detected by 1, t=10502 jiffies, g=166905, q=169 ncpus=2) task:syz-executor state:S stack:24048 pid:15069 tgid:15069 ppid:15068 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline] RIP: 0010:read_seqbegin include/linux/seqlock.h:772 [inline] RIP: 0010:read_seqbegin_or_lock_irqsave include/linux/seqlock.h:1133 [inline] RIP: 0010:thread_group_cputime+0x184/0x820 kernel/sched/cputime.c:336 Code: 31 f6 4c 89 e7 e8 ec d0 04 00 48 8b b4 24 30 01 00 00 4c 89 e7 e8 5c c1 04 00 9c 58 f6 c4 02 5a 4c 8b 14 24 0f 85 bc 04 00 00 <4d> 8d 8a d8 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ca 48 c1 RSP: 0018:ffffc90003b57920 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffc90003b57a70 RCX: 1ffffffff2025621 RDX: 0000000000000000 RSI: ffffffff8163b021 RDI: ffffffff8bb098c0 RBP: 1ffff9200076af33 R08: 0000000000000001 R09: 0000000000000001 R10: ffff88802a0af2c0 R11: 0000000000000000 R12: ffff88802a0af4a0 R13: ffff88807d8e9e00 R14: dffffc0000000000 R15: ffff88807d8ea360 thread_group_cputime_adjusted+0x91/0x110 kernel/sched/cputime.c:639 wait_task_zombie kernel/exit.c:1147 [inline] wait_consider_task+0x2289/0x4100 kernel/exit.c:1420 do_wait_thread kernel/exit.c:1483 [inline] __do_wait+0x1e2/0x890 kernel/exit.c:1601 do_wait+0x219/0x570 kernel/exit.c:1635 kernel_wait4+0x16c/0x280 kernel/exit.c:1794 __do_sys_wait4+0x15f/0x170 kernel/exit.c:1822 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdf55b700d7 RSP: 002b:00007ffef8c89090 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 0000000000000422 RCX: 00007fdf55b700d7 RDX: 0000000040000000 RSI: 00007ffef8c890ec RDI: 00000000ffffffff RBP: 00007ffef8c890ec R08: 0000000000000000 R09: 00007fdf568fe080 R10: 0000000000000000 R11: 0000000000000293 R12: 00005555832c55eb R13: 00005555832c5590 R14: 000000000017d520 R15: 00007ffef8c89140 rcu: rcu_preempt kthread timer wakeup didn't happen for 10481 jiffies! g166905 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=112522 rcu: rcu_preempt kthread starved for 10482 jiffies! g166905 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:27680 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 21400 Comm: syz.0.4869 Not tainted 6.11.0-rc4-syzkaller-00019-gb311c1b497e5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline] RIP: 0010:do_raw_spin_unlock+0x75/0x230 kernel/locking/spinlock_debug.c:141 Code: 48 89 df e8 dd c4 7e 00 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 6c 01 00 00 8b 03 85 c0 0f 84 f5 00 00 00 4c 8d 63 10 RSP: 0018:ffffc90000007d50 EFLAGS: 00000006 RAX: 0000000000000003 RBX: ffff8880615da2e8 RCX: ffffffff8168e7a3 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880615da2e8 RBP: ffff88804a458410 R08: 0000000000000000 R09: ffffed100c2bb45d R10: ffff8880615da2eb R11: 0000000000000000 R12: 0000000000000002 R13: ffff88804a458400 R14: ffff8880615da340 R15: ffff88804a45a400 FS: 00007f1e543de6c0(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c356770 CR3: 000000005f5b6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_unlock+0x1e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] advance_sched+0x611/0xc60 net/sched/sch_taprio.c:981 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x20c/0xcc0 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x10f/0x450 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x66/0x70 kernel/kcov.c:234 Code: 82 f8 15 00 00 83 f8 02 75 20 48 8b 8a 00 16 00 00 8b 92 fc 15 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90003d574a8 EFLAGS: 00000283 RAX: 0000000000001358 RBX: ffffc90003d57578 RCX: ffffc9001346d000 RDX: 0000000000040000 RSI: ffffffff813cdd20 RDI: 0000000000000005 RBP: ffffc90003d57900 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffc90003d57580 R13: ffffc90003d57588 R14: ffffc90003d50000 R15: 0000000000000001 on_stack arch/x86/include/asm/stacktrace.h:58 [inline] stack_access_ok+0xa0/0x270 arch/x86/kernel/unwind_orc.c:393 deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] unwind_next_frame+0x1b94/0x23a0 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:541 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:3106 dentry_free+0xc2/0x160 fs/dcache.c:383 __dentry_kill+0x498/0x600 fs/dcache.c:629 dput.part.0+0x4b1/0x9b0 fs/dcache.c:852 dput+0x1f/0x30 fs/dcache.c:842 handle_mounts fs/namei.c:1579 [inline] step_into+0x1199/0x2230 fs/namei.c:1877 open_last_lookups fs/namei.c:3674 [inline] path_openat+0x44a/0x2d20 fs/namei.c:3883 do_filp_open+0x1dc/0x430 fs/namei.c:3913 do_sys_openat2+0x17a/0x1e0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_open fs/open.c:1439 [inline] __se_sys_open fs/open.c:1435 [inline] __x64_sys_open+0x154/0x1e0 fs/open.c:1435 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1e54979e79 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1e543de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f1e54b16058 RCX: 00007f1e54979e79 RDX: 0000000000000054 RSI: 0000000000044200 RDI: 0000000020000780 RBP: 00007f1e549e7916 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1e54b16058 R15: 00007ffd19ca6be8