rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16883/1:b..l rcu: (detected by 1, t=10502 jiffies, g=73649, q=469 ncpus=2) task:syz.3.3656 state:R running task stack:26888 pid:16883 tgid:16880 ppid:5844 task_flags:0x40054c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1765 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x3842/0x41c0 mm/memory.c:1898 unmap_single_vma mm/memory.c:1941 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1985 exit_mmap+0x248/0xb50 mm/mmap.c:1284 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x22e0 kernel/exit.c:952 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde7f58e929 RSP: 002b:00007fde8033a0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fde7f7b5fa8 RCX: 00007fde7f58e929 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fde7f7b5fac RBP: 00007fde7f7b5fa0 R08: 7fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fde7f7b5fac R13: 0000000000000000 R14: 00007ffcecbb1d00 R15: 00007ffcecbb1de8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g73649 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=36649 rcu: rcu_preempt kthread starved for 10502 jiffies! g73649 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:26152 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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: 15 Comm: ksoftirqd/0 Not tainted 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:do_raw_spin_unlock+0x123/0x240 kernel/locking/spinlock_debug.c:143 Code: 42 80 3c 20 00 74 0c 48 c7 c7 f8 95 fa 8d e8 24 07 85 00 48 83 3d e4 ca 5b 0c 00 0f 84 14 01 00 00 48 89 df e8 ee 78 ca 09 90 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 d9 75 71 ff cc e8 e8 56 1f 03 85 RSP: 0018:ffffc90000007ba8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffff99cdd3b8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff99cdd3b8 RBP: 1ffffffff339ba78 R08: ffffffff99cdd3bb R09: 1ffffffff339ba77 R10: dffffc0000000000 R11: fffffbfff339ba78 R12: dffffc0000000000 R13: 1ffffffff339ba79 R14: ffffffff99cdd3c8 R15: ffffffff99cdd3c0 FS: 0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3171eff8 CR3: 000000000df38000 CR4: 0000000000350ef0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x78/0x110 kernel/locking/spinlock.c:194 debug_object_activate+0x2e2/0x420 lib/debugobjects.c:836 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 4b a5 5e f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 d3 8e 27 f6 65 8b 05 bc ba 33 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90000147860 EFLAGS: 00000206 RAX: c488dad79f592d00 RBX: 0000000000000216 RCX: c488dad79f592d00 RDX: 0000000000000000 RSI: ffffffff8d982307 RDI: 0000000000000001 RBP: ffffc900001478f0 R08: ffffffff8fa10bf7 R09: 1ffffffff1f4217e R10: dffffc0000000000 R11: fffffbfff1f4217f R12: dffffc0000000000 R13: ffffffff8de10c70 R14: ffffffff8de10c30 R15: 1ffff92000028f0c spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:108 __wake_up kernel/sched/wait.c:127 [inline] __wake_up_bit kernel/sched/wait_bit.c:126 [inline] wake_up_bit+0xed/0x130 kernel/sched/wait_bit.c:157 unlock_buffer fs/buffer.c:79 [inline] __end_buffer_read_notouch fs/buffer.c:151 [inline] end_buffer_read_sync+0xb5/0xe0 fs/buffer.c:160 end_bio_bh_io_sync+0xbd/0x120 fs/buffer.c:2783 blk_update_request+0x5eb/0xe70 block/blk-mq.c:987 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1149 blk_complete_reqs block/blk-mq.c:1224 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1229 handle_softirqs+0x286/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:164 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245