rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9107/1:b..l rcu: (detected by 1, t=10502 jiffies, g=27289, q=464 ncpus=2) task:syz.2.753 state:R running task stack:26072 pid:9107 tgid:9083 ppid:5815 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x10/0x330 kernel/locking/lockdep.c:5828 Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 4d 89 cf 41 56 41 89 f6 41 55 <41> 89 d5 41 54 45 89 c4 55 89 cd 53 48 89 fb 48 83 ec 38 65 48 8b RSP: 0018:ffffc900045d72b0 EFLAGS: 00000246 RAX: ffffffff8232b7e3 RBX: 0000000000040004 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e3c9620 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000179 R11: ffff88801bbcd4b0 R12: ffffea0001409b00 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] __mem_cgroup_uncharge_swap+0x37/0xf0 mm/memcontrol.c:5235 __read_swap_cache_async+0x3d0/0x500 mm/swap_state.c:485 swap_cluster_readahead+0x432/0x770 mm/swap_state.c:646 swapin_readahead+0x160/0x1220 mm/swap_state.c:821 do_swap_page+0x962/0x64a0 mm/memory.c:4753 handle_pte_fault mm/memory.c:6276 [inline] __handle_mm_fault+0x19cb/0x2bb0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x54e/0x3590 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x1d8/0x380 mm/gup.c:1963 do_mlock+0x441/0x800 mm/mlock.c:653 __do_sys_mlock mm/mlock.c:661 [inline] __se_sys_mlock mm/mlock.c:659 [inline] __x64_sys_mlock+0x59/0x80 mm/mlock.c:659 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbca318f749 RSP: 002b:00007fbca13b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000095 RAX: ffffffffffffffda RBX: 00007fbca33e6180 RCX: 00007fbca318f749 RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000200000000000 RBP: 00007fbca3213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbca33e6218 R14: 00007fbca33e6180 R15: 00007fff0f134708 rcu: rcu_preempt kthread starved for 10531 jiffies! g27289 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:28440 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 06 60 02 c3 cc cc cc cc 0f 1f 00 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 13 59 13 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6 RAX: 0000000001ccfc25 RBX: 0000000000000001 RCX: ffffffff8b7706d9 RDX: 0000000000000000 RSI: ffffffff8dac200a RDI: ffffffff8bf24280 RBP: ffffed1003b56498 R08: 0000000000000001 R09: ffffed10170a673d R10: ffff8880b85339eb R11: ffff88801dab2ff0 R12: 0000000000000001 R13: ffff88801dab24c0 R14: ffffffff9087f7d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124a09000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b303f8ff8 CR3: 0000000069c2d000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148