rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=7464/1/0x4000000000000000 softirq=65785/65785 fqs=0 rcu: (detected by 1, t=10506 jiffies, g=57105, q=50 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13152 Comm: syz.0.1812 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:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:153 [inline] RIP: 0010:lock_acquire+0x154/0x360 kernel/locking/lockdep.c:5874 Code: 8d e8 e0 68 c8 09 b8 ff ff ff ff 65 0f c1 05 c3 95 fe 10 83 f8 01 0f 85 c9 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 RSP: 0018:ffffc90000007bd0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: a8e1c87e60ef2500 RDX: 0000000000000001 RSI: ffffffff8db6fcc6 RDI: ffffffff8be1ba40 RBP: ffffffff89865a58 R08: 0000000000000000 R09: ffffffff89865a58 R10: dffffc0000000000 R11: ffffed100b09ae5e R12: 0000000000000002 R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000046 FS: 00007f0c0907b6c0(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0c0907af98 CR3: 0000000032f4e000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] advance_sched+0xa14/0xc90 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/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:lock_is_held_type+0x51/0x190 kernel/locking/lockdep.c:5936 Code: 59 3a 04 00 0f 84 fe 00 00 00 65 8b 05 18 44 36 07 85 c0 0f 85 ef 00 00 00 65 4c 8b 2c 25 08 90 9c 92 41 83 bd ec 0a 00 00 00 <0f> 85 d8 00 00 00 89 f5 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 RSP: 0018:ffffc9000b36f898 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: a8e1c87e60ef2500 RDX: ffff888027a40000 RSI: 00000000ffffffff RDI: ffffffff8e13f140 RBP: ffffc9000b36f960 R08: 0000000000000000 R09: ffffffff81ae364e R10: dffffc0000000000 R11: fffffbfff1f4167f R12: 0000000020d5cde6 R13: ffff888027a40000 R14: 1ffff9200166df1c R15: dffffc0000000000 lock_is_held include/linux/lockdep.h:249 [inline] rcu_read_lock_any_held+0x9e/0x120 kernel/rcu/update.c:387 rcu_sync_is_idle include/linux/rcu_sync.h:34 [inline] percpu_down_read_internal include/linux/percpu-rwsem.h:64 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] cpus_read_lock+0x69/0x160 kernel/cpu.c:490 clock_was_set+0x10e/0x7c0 kernel/time/hrtimer.c:962 timekeeping_inject_offset+0x35b/0x4b0 kernel/time/timekeeping.c:1446 do_adjtimex+0x43f/0x9f0 kernel/time/timekeeping.c:2554 do_clock_adjtime kernel/time/posix-timers.c:1162 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1174 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1165 [inline] __x64_sys_clock_adjtime+0x1f4/0x2b0 kernel/time/posix-timers.c:1165 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: 0033:0x7f0c0818eb69 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:00007f0c0907b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f0c083b6160 RCX: 00007f0c0818eb69 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 00007f0c08211df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f0c083b6160 R15: 00007ffe826ab358 rcu: rcu_preempt kthread starved for 10506 jiffies! g57105 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:26792 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 de 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 ad 21 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0000:ffffc90000197de0 EFLAGS: 000002c2 RAX: 6dc972f28d19c100 RBX: ffffffff81976918 RCX: 6dc972f28d19c100 RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40 RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fa0b3f0 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003ad3b40 FS: 0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555590b7a588 CR3: 0000000032f4e000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147