rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23072/1:b..l (detected by 0, t=10502 jiffies, g=127309, q=71 ncpus=2) task:syz.9.4671 state:R running task stack:24776 pid:23072 ppid:18792 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] loop_queue_work drivers/block/loop.c:894 [inline] loop_queue_rq+0x9d9/0xac0 drivers/block/loop.c:1874 __blk_mq_issue_directly block/blk-mq.c:2631 [inline] __blk_mq_try_issue_directly+0x4ab/0x7a0 block/blk-mq.c:2684 blk_mq_try_issue_directly+0x28/0x1f0 block/blk-mq.c:2708 blk_mq_submit_bio+0x1221/0x1f80 block/blk-mq.c:3045 __submit_bio+0x1a7/0x290 block/blk-core.c:591 __submit_bio_noacct_mq block/blk-core.c:668 [inline] submit_bio_noacct_nocheck+0x7b4/0xa70 block/blk-core.c:697 submit_bh fs/buffer.c:2707 [inline] __sync_dirty_buffer+0x228/0x360 fs/buffer.c:2745 ntfs_write_bh+0x583/0x730 fs/ntfs3/fsntfs.c:1450 mi_write+0x80/0x1c0 fs/ntfs3/record.c:382 ni_write_inode+0x636/0x1050 fs/ntfs3/frecord.c:3422 ntfs_truncate fs/ntfs3/file.c:430 [inline] ntfs3_setattr+0x9ad/0xc00 fs/ntfs3/file.c:710 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x197/0x220 fs/open.c:65 handle_truncate fs/namei.c:3285 [inline] do_open fs/namei.c:3630 [inline] path_openat+0x27f2/0x2e70 fs/namei.c:3783 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810 do_sys_openat2+0x142/0x490 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_creat fs/open.c:1412 [inline] __se_sys_creat fs/open.c:1406 [inline] __x64_sys_creat+0x8c/0xb0 fs/open.c:1406 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbd0d58ebe9 RSP: 002b:00007fbd0b7f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fbd0d7c5fa0 RCX: 00007fbd0d58ebe9 RDX: 0000000000000000 RSI: 071283578ac7c5cd RDI: 0000200000000180 RBP: 00007fbd0d611e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbd0d7c6038 R14: 00007fbd0d7c5fa0 R15: 00007ffea21ea278 rcu: rcu_preempt kthread starved for 10541 jiffies! g127309 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:26912 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 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: 23075 Comm: syz.6.4672 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__kasan_check_read+0x6/0x10 mm/kasan/shadow.c:31 Code: 41 5f 5d c3 48 c7 c7 33 73 5a 8c eb 0a 48 c7 c7 cc bc 43 8c 48 89 de e8 38 48 3b 08 31 ed eb d7 00 00 cc cc 89 f6 48 8b 0c 24 <31> d2 e9 a3 ec ff ff 0f 1f 00 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 RSP: 0018:ffffc900001e0cd8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8162f209 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e1f7128 RBP: ffffc900001e0de8 R08: 0000000000000001 R09: 0000000000000000 R10: fffffbfff1c3ee26 R11: 1ffffffff1c3ee25 R12: 0000000000000001 R13: 1ffff9200003c1a8 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f83285d16c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c4064af CR3: 000000005e6c8000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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+0xd9/0x490 kernel/locking/lockdep.c:5633 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 hrtimer_interrupt+0xf8/0x9c0 kernel/time/hrtimer.c:1859 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: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 18 42 f7 48 89 df e8 e6 dd 42 f7 e8 61 d1 65 f7 fb bf 01 00 00 00 46 5b 36 f7 65 8b 05 67 14 e1 75 85 c0 74 02 5b c3 e8 b4 25 df RSP: 0018:ffffc900040a7bb8 EFLAGS: 00000286 RAX: 0d987155a7992700 RBX: ffff888065580940 RCX: 0d987155a7992700 RDX: dffffc0000000000 RSI: ffffffff8a8c0300 RDI: 0000000000000001 RBP: ffff888065580bd8 R08: dffffc0000000000 R09: ffffed100cab0129 R10: ffffed100cab0129 R11: 1ffff1100cab0128 R12: 1ffff1100cab017b R13: 0000000000000011 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+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 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:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f832778ebe9 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:00007f83285d10e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f83279c5fa8 RCX: 00007f832778ebe9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f83279c5fa8 RBP: 00007f83279c5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f83279c6038 R14: 00007ffea1ad8560 R15: 00007ffea1ad8648 vkms_vblank_simulate: vblank timer overrun