rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=381/1/0x4000000000000000 softirq=21020/21020 fqs=0 (detected by 1, t=10504 jiffies, g=28781, q=918) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7771 Comm: syz.2.1021 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] RIP: 0010:do_raw_spin_lock+0xa0/0x280 kernel/locking/spinlock_debug.c:114 Code: 0f b6 04 38 84 c0 0f 85 9a 01 00 00 41 8b 06 3d ad 4e ad de 0f 85 16 01 00 00 4c 8d 63 10 4d 89 e6 49 c1 ee 03 43 80 3c 3e 00 <74> 08 4c 89 e7 e8 a6 01 60 00 49 8b 04 24 65 48 8b 0d 2a 37 a5 7e RSP: 0018:ffffc90000007b40 EFLAGS: 00000046 RAX: 00000000dead4ead RBX: ffffffff96325a48 RCX: 1ffff92000000f6c RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff96325a48 RBP: ffffc90000007bf0 R08: dffffc0000000000 R09: fffffbfff1ff3619 R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: ffffffff96325a58 R13: ffffffff96325a40 R14: 1ffffffff2c64b4b R15: dffffc0000000000 FS: 00007fca3d3566c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3071eff8 CR3: 0000000060499000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline] _raw_spin_lock_irqsave+0xb0/0xf0 kernel/locking/spinlock.c:162 debug_object_deactivate+0x63/0x340 lib/debugobjects.c:749 debug_hrtimer_deactivate kernel/time/hrtimer.c:415 [inline] debug_deactivate+0x1d/0x1c0 kernel/time/hrtimer.c:471 __run_hrtimer kernel/time/hrtimer.c:1658 [inline] __hrtimer_run_queues+0x2db/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:ffffc9000357fd20 EFLAGS: 00000282 RAX: 1bf230984a6c1600 RBX: ffff88805e4dd888 RCX: 1bf230984a6c1600 RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001 RBP: 7fffffffffffffff R08: dffffc0000000000 R09: ffffed100bc9bb12 R10: ffffed100bc9bb12 R11: 1ffff1100bc9bb11 R12: 1ffff1100bc9bb10 R13: ffff88805e4dd800 R14: ffff888076ead401 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: 0033:0x7fca3f4ee929 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:00007fca3d356038 EFLAGS: 00000246 ORIG_RAX: 000000000000011e RAX: ffffffffffffffda RBX: 00007fca3f715fa0 RCX: 00007fca3f4ee929 RDX: 0000200000000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00007fca3f570b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fca3f715fa0 R15: 00007ffe99eed138 rcu: rcu_preempt kthread timer wakeup didn't happen for 10503 jiffies! g28781 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=11442 rcu: rcu_preempt kthread starved for 10504 jiffies! g28781 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:27008 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: 7771 Comm: syz.2.1021 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__lock_release kernel/locking/lockdep.c:5311 [inline] RIP: 0010:lock_release+0x254/0x870 kernel/locking/lockdep.c:5643 Code: 83 3e 00 0f 85 ca 03 00 00 4d 8d 74 24 20 4c 89 f3 48 c1 eb 03 42 0f b6 04 2b 84 c0 4c 8b 7c 24 20 0f 85 90 04 00 00 41 8b 06 <3d> 00 00 10 00 72 3c 89 c1 81 e1 00 00 f0 ff 25 ff ff 0f 00 8d bc RSP: 0018:ffffc90000007ae0 EFLAGS: 00000046 RAX: 00000000000c4000 RBX: 1ffff1100497c167 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff96325a60 RDI: ffff888024be0b18 RBP: ffffc90000007bf0 R08: dffffc0000000000 R09: fffffbfff1ad157e R10: fffffbfff1ad157e R11: 1ffffffff1ad157d R12: ffff888024be0b18 R13: dffffc0000000000 R14: ffff888024be0b38 R15: 1ffff92000000f68 FS: 00007fca3d3566c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3071eff8 CR3: 0000000060499000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x6d/0x100 kernel/locking/spinlock.c:194 debug_object_activate+0x2d2/0x480 lib/debugobjects.c:712 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:ffffc9000357fd20 EFLAGS: 00000282 RAX: 1bf230984a6c1600 RBX: ffff88805e4dd888 RCX: 1bf230984a6c1600 RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001 RBP: 7fffffffffffffff R08: dffffc0000000000 R09: ffffed100bc9bb12 R10: ffffed100bc9bb12 R11: 1ffff1100bc9bb11 R12: 1ffff1100bc9bb10 R13: ffff88805e4dd800 R14: ffff888076ead401 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: 0033:0x7fca3f4ee929 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:00007fca3d356038 EFLAGS: 00000246 ORIG_RAX: 000000000000011e RAX: ffffffffffffffda RBX: 00007fca3f715fa0 RCX: 00007fca3f4ee929 RDX: 0000200000000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00007fca3f570b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fca3f715fa0 R15: 00007ffe99eed138