rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10931/1:b..l (detected by 0, t=10502 jiffies, g=50677, q=138 ncpus=2) task:syz.3.2017 state:R running task stack:24760 pid:10931 ppid:4251 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5243 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6560 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_is_held_type+0x137/0x180 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90004a672e8 EFLAGS: 00000206 RAX: a287c00025a6f300 RBX: 0000000000000002 RCX: 0000000080000000 RDX: ffff8880252e0000 RSI: ffffffff8b0c2ec0 RDI: ffffffff8b5f6f80 RBP: 0000000000000000 R08: ffffffff842ff33c R09: fffffbfff225724d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246 R13: ffff8880252e0000 R14: 00000000ffffffff R15: ffffffff8d3574b8 lock_is_held include/linux/lockdep.h:283 [inline] task_css include/linux/cgroup.h:509 [inline] blkcg_css+0xc8/0x1c0 block/blk-cgroup.c:77 blk_cgroup_congested+0xb9/0x220 block/blk-cgroup.c:2003 __cgroup_throttle_swaprate+0x6d/0x1b0 mm/swapfile.c:3671 cgroup_throttle_swaprate include/linux/swap.h:662 [inline] folio_throttle_swaprate include/linux/swap.h:671 [inline] shmem_add_to_page_cache+0xb90/0x1e60 mm/shmem.c:717 shmem_get_folio_gfp+0x164e/0x3470 mm/shmem.c:1971 shmem_fault+0x235/0x9c0 mm/shmem.c:2156 __do_fault+0x136/0x4f0 mm/memory.c:4278 do_read_fault mm/memory.c:4629 [inline] do_fault mm/memory.c:4758 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x3410/0x5340 mm/memory.c:5292 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x4f3/0x1190 mm/gup.c:1250 populate_vma_page_range+0x217/0x2b0 mm/gup.c:1607 __mm_populate+0x275/0x440 mm/gup.c:1721 mm_populate include/linux/mm.h:2823 [inline] vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:525 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5b9c18d169 RSP: 002b:00007f5b9cfde038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f5b9c3a5fa0 RCX: 00007f5b9c18d169 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000400000000000 RBP: 00007f5b9c20e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5b9c3a5fa0 R15: 00007ffe9ba759b8 rcu: rcu_preempt kthread starved for 10528 jiffies! g50677 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26048 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5243 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6560 schedule+0xbf/0x180 kernel/sched/core.c:6636 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.130-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567 Code: d9 ce f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 94 96 d5 f6 0f 1f 44 00 00 e8 ba d5 ce f6 0f 00 2d 53 f4 ad 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 ab 38 26 f7 RSP: 0018:ffffffff8d007b20 EFLAGS: 000002d3 RAX: ffffffff8abbc3c6 RBX: 0000000000000000 RCX: ffffffff8d0bd980 RDX: 0000000000000000 RSI: ffffffff8b0c1d40 RDI: ffffffff8b5f6f80 RBP: ffffffff8d007bb0 R08: ffffffff8abbc3a8 R09: fffffbfff1a17b31 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1a00f64 R13: ffff8881476b0004 R14: ffffffff8d007b40 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2df7b9 CR3: 000000005d672000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:704 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3ce/0x680 kernel/sched/idle.c:303 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401 rest_init+0x2da/0x300 init/main.c:733 arch_call_rest_init+0xa/0xa init/main.c:893 start_kernel+0x496/0x53f init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb