rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=5474/1/0x4000000000000000 softirq=18120/18120 fqs=0 rcu: (detected by 1, t=10502 jiffies, g=13409, q=399 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6078 Comm: syz.3.20 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 74 6e fa 0b 48 89 de 5b e9 33 20 55 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 90 9c 92 65 8b 15 58 6a RSP: 0018:ffffc90000007d38 EFLAGS: 00000097 RAX: ffffffff81ae77c8 RBX: ffff8880b8627c08 RCX: 0000000000010000 RDX: ffff88807a9c1e00 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffffc90000007e90 R08: ffff88807ebb515f R09: 1ffff1100fd76a2b R10: dffffc0000000000 R11: ffffed100fd76a2c R12: ffff88807ebb5340 R13: 0000000000000000 R14: 0000000000000001 R15: ffff88807a9c28d8 FS: 00007fb43f28c6c0(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb43f28bf98 CR3: 000000007d7aa000 CR4: 00000000003526f0 Call Trace: cpu_max_bits_warn include/linux/cpumask.h:135 [inline] cpumask_check include/linux/cpumask.h:142 [inline] cpumask_test_cpu include/linux/cpumask.h:638 [inline] cpu_online include/linux/cpumask.h:1197 [inline] trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline] __run_hrtimer kernel/time/hrtimer.c:1764 [inline] __hrtimer_run_queues+0x577/0xc60 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+0x108/0x410 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 fb 9b 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 63 cc 27 f6 65 8b 05 1c 7a 33 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc900038f7b60 EFLAGS: 00000206 RAX: 851abc90b4e84000 RBX: 0000000000000a06 RCX: 851abc90b4e84000 RDX: 0000000000000007 RSI: ffffffff8d982fba RDI: 0000000000000001 RBP: ffffc900038f7bf0 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e R10: dffffc0000000000 R11: fffffbfff1f4167f R12: dffffc0000000000 R13: ffff8880b8627ac0 R14: ffff8880b8627ac0 R15: 1ffff9200071ef6c clock_was_set+0x63b/0x7c0 kernel/time/hrtimer.c:972 do_settimeofday64+0x2ec/0x5e0 kernel/time/timekeeping.c:1407 __do_sys_clock_settime kernel/time/posix-timers.c:1132 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1116 [inline] __x64_sys_clock_settime+0x229/0x280 kernel/time/posix-timers.c:1116 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb43e38ebe9 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:00007fb43f28c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007fb43e5b6090 RCX: 00007fb43e38ebe9 RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000000 RBP: 00007fb43e411e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb43e5b6128 R14: 00007fb43e5b6090 R15: 00007fff9d9ef4d8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=3818 rcu: rcu_preempt kthread starved for 10502 jiffies! g13409 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 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+0x70e/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