rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=9604/1/0x4000000000000000 softirq=89060/89060 fqs=0 (detected by 1, t=10502 jiffies, g=125541, q=813 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3539 Comm: syz-fuzzer Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x36/0xb0 kernel/rcu/tree.c:721 Code: e8 2f f0 16 09 89 c3 83 f8 08 73 76 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 50 08 b1 8c 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 60 bd 6e 00 48 c7 c3 a8 56 03 00 49 03 1e 48 89 RSP: 0018:ffffc90000007b40 EFLAGS: 00000046 RAX: 1ffffffff196210a RBX: 0000000000000000 RCX: ffffffff816a53fb RDX: 0000000000000000 RSI: ffffffff8b3d2d00 RDI: ffffffff8b3d2cc0 RBP: ffffc90000007ca8 R08: dffffc0000000000 R09: fffffbfff1ce6d46 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000000f74 R13: dffffc0000000000 R14: ffffffff8cb10850 R15: dffffc0000000000 FS: 000000000240c890(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffa462af68 CR3: 000000001f678000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xfa/0x5a0 kernel/locking/lockdep.c:5633 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] advance_sched+0x6ec/0x970 net/sched/sch_taprio.c:753 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:274 [inline] RIP: 0010:_raw_write_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:358 Code: 81 b2 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 0e 14 d6 f6 48 89 df e8 06 63 d7 f6 e8 11 e2 fc f6 fb bf 01 00 00 00 26 de c9 f6 65 8b 05 c7 09 6e 75 85 c0 74 02 5b c3 e8 04 28 6c RSP: 0018:ffffc900039efb50 EFLAGS: 00000282 RAX: cca0f8f917953900 RBX: ffff888019f27940 RCX: ffffffff816ac11a RDX: dffffc0000000000 RSI: ffffffff8aebeec0 RDI: 0000000000000001 RBP: ffffc900039efdd8 R08: dffffc0000000000 R09: fffffbfff209305a R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff110033e4f27 R13: dffffc0000000000 R14: ffffc900039efcc0 R15: ffff888019f27938 ep_start_scan fs/eventpoll.c:626 [inline] ep_send_events fs/eventpoll.c:1658 [inline] ep_poll fs/eventpoll.c:1827 [inline] do_epoll_wait+0xa1d/0x1e60 fs/eventpoll.c:2262 do_epoll_pwait+0x56/0x1d0 fs/eventpoll.c:2296 __do_sys_epoll_pwait fs/eventpoll.c:2309 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2303 [inline] __x64_sys_epoll_pwait+0x2b4/0x300 fs/eventpoll.c:2303 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:00007ffef490b2d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000040720e RDX: 0000000000000080 RSI: 00007ffef490b3a8 RDI: 0000000000000004 RBP: 00007ffef490b320 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffef490b3b0 R13: 0000000000000007 R14: 000000000240a520 R15: 0000000000000009 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g125541 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=56085 rcu: rcu_preempt kthread starved for 10502 jiffies! g125541 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:27032 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1120 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3539 Comm: syz-fuzzer Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4724 [inline] RIP: 0010:__lock_acquire+0x552/0x1f80 kernel/locking/lockdep.c:4999 Code: 41 8b 1e 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 20 82 49 90 be 08 00 00 00 e8 d6 9f 77 00 48 0f a3 1d de 22 df 0e <73> 1f 48 8d 04 5b 48 c1 e0 06 48 8d 98 20 e1 18 90 48 ba 00 00 00 RSP: 0018:ffffc90000007a00 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816a5f3a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90498220 RBP: 0000000000000002 R08: dffffc0000000000 R09: fffffbfff2093045 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807c2be418 R13: ffff88807c2bd940 R14: ffff88807c2be490 R15: 1ffff1100f857c92 FS: 000000000240c890(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffa462af68 CR3: 000000001f678000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x63/0x380 lib/debugobjects.c:752 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:481 __run_hrtimer kernel/time/hrtimer.c:1654 [inline] __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:274 [inline] RIP: 0010:_raw_write_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:358 Code: 81 b2 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 0e 14 d6 f6 48 89 df e8 06 63 d7 f6 e8 11 e2 fc f6 fb bf 01 00 00 00 26 de c9 f6 65 8b 05 c7 09 6e 75 85 c0 74 02 5b c3 e8 04 28 6c RSP: 0018:ffffc900039efb50 EFLAGS: 00000282 RAX: cca0f8f917953900 RBX: ffff888019f27940 RCX: ffffffff816ac11a RDX: dffffc0000000000 RSI: ffffffff8aebeec0 RDI: 0000000000000001 RBP: ffffc900039efdd8 R08: dffffc0000000000 R09: fffffbfff209305a R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff110033e4f27 R13: dffffc0000000000 R14: ffffc900039efcc0 R15: ffff888019f27938 ep_start_scan fs/eventpoll.c:626 [inline] ep_send_events fs/eventpoll.c:1658 [inline] ep_poll fs/eventpoll.c:1827 [inline] do_epoll_wait+0xa1d/0x1e60 fs/eventpoll.c:2262 do_epoll_pwait+0x56/0x1d0 fs/eventpoll.c:2296 __do_sys_epoll_pwait fs/eventpoll.c:2309 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2303 [inline] __x64_sys_epoll_pwait+0x2b4/0x300 fs/eventpoll.c:2303 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:00007ffef490b2d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000040720e RDX: 0000000000000080 RSI: 00007ffef490b3a8 RDI: 0000000000000004 RBP: 00007ffef490b320 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffef490b3b0 R13: 0000000000000007 R14: 000000000240a520 R15: 0000000000000009