rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5819/1:b..l rcu: (detected by 0, t=10502 jiffies, g=29961, q=75 ncpus=2) task:syz-executor state:R running task stack:22528 pid:5819 tgid:5819 ppid:5815 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6944 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1201 [inline] copy_pmd_range mm/memory.c:1262 [inline] copy_pud_range mm/memory.c:1299 [inline] copy_p4d_range mm/memory.c:1323 [inline] copy_page_range+0x1e7f/0x5690 mm/memory.c:1421 dup_mmap kernel/fork.c:748 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm kernel/fork.c:1752 [inline] copy_process+0x7ccb/0x8c50 kernel/fork.c:2403 kernel_clone+0xfd/0x960 kernel/fork.c:2815 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5461f839d3 RSP: 002b:00007ffc520a5928 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5461f839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555559fcf7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000054a0d R15: 00007ffc520a5ac0 rcu: rcu_preempt kthread starved for 10502 jiffies! g29961 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:28344 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10468 Comm: syz.3.1425 Not tainted 6.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:hlock_class+0x49/0x130 kernel/locking/lockdep.c:230 Code: 74 08 3c 03 0f 8e da 00 00 00 0f b7 5b 20 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 c0 2c ec 96 f2 46 87 00 48 0f a3 1d da 76 56 15 73 13 48 69 c3 c8 00 00 00 RSP: 0018:ffffc90000a18ae0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffff110070265f4 RSI: 0000000000000008 RDI: ffffffff96ec2cc0 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 000000000000000a R11: 0000000000000002 R12: 0000000000000002 R13: ffff888038132440 R14: 0000000000000000 R15: ffff888038132f80 FS: 00007f812ab706c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f812ab6ff98 CR3: 000000004a848000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_wait_context kernel/locking/lockdep.c:4852 [inline] __lock_acquire+0x410/0x3c40 kernel/locking/lockdep.c:5178 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_deactivate+0x13b/0x370 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:460 [inline] debug_deactivate kernel/time/hrtimer.c:502 [inline] __run_hrtimer kernel/time/hrtimer.c:1769 [inline] __hrtimer_run_queues+0x47c/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 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+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 b6 da 3c f6 48 89 df e8 0e 5a 3d f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 85 2f 2e f6 65 8b 05 a6 13 aa 74 85 c0 74 16 5b RSP: 0018:ffffc90003827ca8 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff8880b862c680 RCX: 1ffffffff2dd8673 RDX: 0000000000000000 RSI: ffffffff8b6cec80 RDI: ffffffff8bd35640 RBP: 0000000000000282 R08: 0000000000000001 R09: fffffbfff2dd8598 R10: ffffffff96ec2cc7 R11: 0000000000000001 R12: 0000000000000004 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 clock_was_set+0x591/0x850 kernel/time/hrtimer.c:984 do_settimeofday64+0x305/0x4c0 kernel/time/timekeeping.c:1381 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1135 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1119 [inline] __x64_sys_clock_settime+0x1bf/0x2a0 kernel/time/posix-timers.c:1119 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8129d8d169 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:00007f812ab70038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f8129fa6160 RCX: 00007f8129d8d169 RDX: 0000000000000000 RSI: 0000400000000040 RDI: 0000000000000000 RBP: 00007f8129e0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f8129fa6160 R15: 00007fffb65d8008