rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=ecf/1/0x4000000000000000 softirq=50515/50515 fqs=0 (detected by 1, t=10506 jiffies, g=71941, q=651) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15757 Comm: syz.0.4610 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:mark_lock+0xfd/0x320 kernel/locking/lockdep.c:4610 Code: 83 c7 50 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 24 9d 60 00 b8 01 00 00 00 45 85 27 74 50 48 83 c4 08 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 e8 f6 bd 7b 02 85 c0 74 c1 48 c7 c0 88 df RSP: 0018:ffffc900000078b8 EFLAGS: 00000082 RAX: 0000000000000001 RBX: ffff88802b9b6428 RCX: ffffffff815c9cb4 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ff9b0c8 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ff361a R10: fffffbfff1ff361a R11: 1ffffffff1ff3619 R12: ffff88802b9b6450 R13: dffffc0000000000 R14: ffff88802b9b6430 R15: ffffffff8f927590 FS: 00007f78e9baa6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdf91405000 CR3: 000000007afff000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4483 [inline] __lock_acquire+0xc11/0x7c60 kernel/locking/lockdep.c:4966 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1694 [inline] __hrtimer_run_queues+0x5ff/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 9a b1 f7 48 89 df e8 56 6f b2 f7 e8 a1 13 d3 f7 fb bf 01 00 00 00 86 93 a6 f7 65 8b 05 27 a3 57 76 85 c0 74 02 5b c3 e8 d4 ad 55 RSP: 0018:ffffc9000328fd20 EFLAGS: 00000282 RAX: 5d83ea0dc0b2c400 RBX: ffff88805fd6bc88 RCX: 5d83ea0dc0b2c400 RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001 RBP: 7fffffffffffffff R08: dffffc0000000000 R09: ffffed100bfad792 R10: ffffed100bfad792 R11: 1ffff1100bfad791 R12: 1ffff1100bfad790 R13: ffff88805fd6bc00 R14: ffff88801f353181 R15: 7fffffffffffffff spin_unlock_irq include/linux/spinlock.h:413 [inline] do_timerfd_settime+0xe3a/0x1080 fs/timerfd.c:521 __do_sys_timerfd_settime fs/timerfd.c:567 [inline] __se_sys_timerfd_settime fs/timerfd.c:558 [inline] __x64_sys_timerfd_settime+0x15e/0x210 fs/timerfd.c:558 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f78ebd42929 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:00007f78e9baa038 EFLAGS: 00000246 ORIG_RAX: 000000000000011e RAX: ffffffffffffffda RBX: 00007f78ebf69fa0 RCX: 00007f78ebd42929 RDX: 0000200000000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00007f78ebdc4b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f78ebf69fa0 R15: 00007fff26e96c08 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g71941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=31038 rcu: rcu_preempt kthread starved for 10506 jiffies! g71941 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:28032 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 15757 Comm: syz.0.4610 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4702 [inline] RIP: 0010:__lock_acquire+0x6e2/0x7c60 kernel/locking/lockdep.c:4962 Code: 44 89 f0 83 c0 fe 0f 88 70 01 00 00 44 89 fb 81 e3 ff ff ff 7f 83 f8 31 73 43 48 8d 04 9b 49 8d 5c c5 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 00 84 c0 75 45 8b 1b 48 8b 44 24 58 42 0f b6 04 00 84 RSP: 0018:ffffc90000007860 EFLAGS: 00000802 RAX: 1ffff11005736c8a RBX: ffff88802b9b6450 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ff9b0c0 RBP: ffffc90000007ab0 R08: dffffc0000000000 R09: fffffbfff1ff3619 R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: 0000000000000000 R13: ffff88802b9b6450 R14: 0000000000000002 R15: 0000000000000000 FS: 00007f78e9baa6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdf91405000 CR3: 000000007afff000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 debug_object_activate+0x65/0x480 lib/debugobjects.c:694 debug_hrtimer_activate kernel/time/hrtimer.c:410 [inline] debug_activate kernel/time/hrtimer.c:465 [inline] enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1074 __run_hrtimer kernel/time/hrtimer.c:1707 [inline] __hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 9a b1 f7 48 89 df e8 56 6f b2 f7 e8 a1 13 d3 f7 fb bf 01 00 00 00 86 93 a6 f7 65 8b 05 27 a3 57 76 85 c0 74 02 5b c3 e8 d4 ad 55 RSP: 0018:ffffc9000328fd20 EFLAGS: 00000282 RAX: 5d83ea0dc0b2c400 RBX: ffff88805fd6bc88 RCX: 5d83ea0dc0b2c400 RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001 RBP: 7fffffffffffffff R08: dffffc0000000000 R09: ffffed100bfad792 R10: ffffed100bfad792 R11: 1ffff1100bfad791 R12: 1ffff1100bfad790 R13: ffff88805fd6bc00 R14: ffff88801f353181 R15: 7fffffffffffffff spin_unlock_irq include/linux/spinlock.h:413 [inline] do_timerfd_settime+0xe3a/0x1080 fs/timerfd.c:521 __do_sys_timerfd_settime fs/timerfd.c:567 [inline] __se_sys_timerfd_settime fs/timerfd.c:558 [inline] __x64_sys_timerfd_settime+0x15e/0x210 fs/timerfd.c:558 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f78ebd42929 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:00007f78e9baa038 EFLAGS: 00000246 ORIG_RAX: 000000000000011e RAX: ffffffffffffffda RBX: 00007f78ebf69fa0 RCX: 00007f78ebd42929 RDX: 0000200000000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00007f78ebdc4b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f78ebf69fa0 R15: 00007fff26e96c08