rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5671/1:b..l (detected by 0, t=10502 jiffies, g=21253, q=246 ncpus=2) task:syz.3.323 state:R running task stack:22832 pid:5671 ppid:4278 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:kasan_check_range+0x1b7/0x290 mm/kasan/generic.c:189 Code: 49 8d 5f 07 4d 85 ff 49 0f 49 df 48 83 e3 f8 49 29 df 74 0e 41 80 3b 00 75 69 49 ff c3 49 ff cf 75 f2 5b 41 5c 41 5e 41 5f 5d 45 84 ff 0f 85 91 00 00 00 41 f7 c7 00 ff 00 00 0f 85 89 00 00 RSP: 0018:ffffc9000d24ef18 EFLAGS: 00000256 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81643f64 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e1fcb68 RBP: ffffc9000d24f040 R08: ffffffff8e1fcb6f R09: 1ffffffff1c3f96d R10: dffffc0000000000 R11: fffffbfff1c3f96e R12: 0000000000000000 R13: 1ffff92001a49df0 R14: 0000000000000000 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:444 [inline] cpu_online include/linux/cpumask.h:1030 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xd4/0x4a0 kernel/locking/lockdep.c:5633 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] page_ext_get+0x3a/0x2a0 mm/page_ext.c:157 __reset_page_owner+0x31/0x1a0 mm/page_owner.c:144 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1486 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3554 release_pages+0x1fa6/0x2220 mm/swap.c:1035 __pagevec_release+0x6d/0xe0 mm/swap.c:1055 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x7c2/0x20c0 mm/shmem.c:946 shmem_truncate_range mm/shmem.c:1062 [inline] shmem_evict_inode+0x25b/0xa80 mm/shmem.c:1171 evict+0x4c9/0x8d0 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfa/0x1d0 fs/dcache.c:918 __fput+0x5e0/0x920 fs/file_table.c:328 task_work_run+0x1d0/0x260 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x982/0x2480 kernel/exit.c:880 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1485 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f0f8cd9aec1 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f0f8d016090 RCX: 00007f0f8cd9aeb9 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f0f8ce08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f0f8d016128 R14: 00007f0f8d016090 R15: 00007ffee46b9248 rcu: rcu_preempt kthread starved for 10436 jiffies! g21253 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:R running task stack:26864 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6015 Comm: syz.3.421 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:mark_usage kernel/locking/lockdep.c:4514 [inline] RIP: 0010:__lock_acquire+0xbf9/0x7d10 kernel/locking/lockdep.c:5003 Code: f6 ba 01 00 00 00 e8 66 a9 00 00 49 b8 00 00 00 00 00 fc ff df 85 c0 0f 84 bb 1c 00 00 48 8b 84 24 d0 00 00 00 42 0f b6 04 00 <84> c0 0f 85 c9 60 00 00 48 8b 84 24 b8 00 00 00 83 38 00 74 7c 4c RSP: 0018:ffffc900001e09c0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffffffff9047f879 RCX: ffffffff8164fa44 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af4248 RBP: ffffc900001e0c10 R08: dffffc0000000000 R09: 1ffffffff215e849 R10: dffffc0000000000 R11: fffffbfff215e84a R12: ffff88807977d940 R13: 0000000000000008 R14: ffff88807977e448 R15: ffff88807977e468 FS: 00007f0f8dc176c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000058 CR3: 0000000046df0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:102 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get_update_offsets_now+0x95/0x3e0 kernel/time/timekeeping.c:2320 hrtimer_update_base kernel/time/hrtimer.c:659 [inline] hrtimer_interrupt+0x130/0x9c0 kernel/time/hrtimer.c:1855 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 9e 12 2e f7 48 89 df e8 e6 da 2e f7 e8 a1 2d 52 f7 fb bf 01 00 00 00 86 3b 22 f7 65 8b 05 47 c0 cb 75 85 c0 74 02 5b c3 e8 94 d4 c9 RSP: 0018:ffffc90003c27b98 EFLAGS: 00000282 RAX: 68bf06f3cb436b00 RBX: ffff88804e00e5c0 RCX: 68bf06f3cb436b00 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000001 RBP: ffff88804e00ea58 R08: ffff88804e00e5c3 R09: 1ffff11009c01cb8 R10: dffffc0000000000 R11: ffffed1009c01cb9 R12: 1ffff11009c01d4b R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1163/0x1350 kernel/signal.c:2874 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0f8cd9aeb7 Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 RSP: 002b:00007f0f8dc170e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f0f8d015fa8 RCX: 00007f0f8cd9aeb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0f8d015fa8 RBP: 00007f0f8d015fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0f8d016038 R14: 00007ffee46b9160 R15: 00007ffee46b9248