rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=4693, q=32 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294953417-4294942914), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g4693 f0x2 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:26448 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 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: 5253 Comm: syz-executor475 Not tainted 6.11.0-syzkaller-04003-gfc1dc0d50780 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__kasan_check_write+0x0/0x20 mm/kasan/shadow.c:36 Code: 48 8b 0c 24 31 d2 e9 6f e6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 3c e6 ff ff 66 2e RSP: 0018:ffffc90000a18bd8 EFLAGS: 00000097 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: 0000000000a18c03 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8880b892c880 RBP: ffffc90000a18cb0 R08: ffffffff9423484f R09: 1ffffffff2846909 R10: dffffc0000000000 R11: fffffbfff284690a R12: ffff8880b892c880 R13: 1ffff92000143188 R14: ffffc90000a18c40 R15: 1ffff11017125911 FS: 000055558b9b13c0(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f239b953880 CR3: 000000007bbce000 CR4: 0000000000350ef0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x142/0x370 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:120 [inline] _raw_spin_lock_irq+0xdf/0x120 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1695 [inline] __hrtimer_run_queues+0x670/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline] __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1043 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ca a2 a8 f5 48 89 df e8 42 e6 a9 f5 e8 ed e6 d3 f5 fb bf 01 00 00 00 52 a9 9b f5 65 8b 05 33 7e 3c 74 85 c0 74 06 5b e9 ac ea 28 00 RSP: 0018:ffffc9000414fc70 EFLAGS: 00000282 RAX: 4b5182d4e46ac600 RBX: ffff88802f014a00 RCX: ffffffff9a38b903 RDX: dffffc0000000000 RSI: ffffffff8c0ad8e0 RDI: 0000000000000001 RBP: ffffc9000414fdb0 R08: ffffffff901bb8ef R09: 1ffffffff203771d R10: dffffc0000000000 R11: fffffbfff203771e R12: 0000000000000021 R13: 1ffff11005e029d3 R14: ffff88802f014e98 R15: ffff88802f014a00 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x14df/0x1740 kernel/signal.c:2920 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f239b93a6a9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 1d 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcd41ee858 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f239b93a6a9 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007f239b800990 R09: 00007f239b800990 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f239b990f7c R13: 00007f239b98a117 R14: 00007ffcd41ee890 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.980 msecs