rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P19982/1:b..l rcu: (detected by 0, t=10502 jiffies, g=116037, q=912 ncpus=2) task:syz.3.3413 state:R running task stack:25464 pid:19982 tgid:19979 ppid:5826 task_flags:0x40054c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline] RIP: 0010:lock_acquire+0x94/0x360 kernel/locking/lockdep.c:5842 Code: 0f 84 d7 01 00 00 83 3d 99 bb df 0d 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 c3 5a 81 00 83 3d 7c bb df 0d 00 <0f> 84 fa 00 00 00 65 8b 05 5f 1f d4 10 85 c0 0f 85 eb 00 00 00 65 RSP: 0018:ffffc900037ff008 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: c561ce935242b500 RDX: 0000000000000000 RSI: ffffffff82281125 RDI: 1ffffffff1be770c RBP: ffffffff82281109 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff9400005a961 R12: 0000000000000002 R13: ffffffff8df3b860 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline] percpu_ref_put+0x35/0x180 include/linux/percpu-refcount.h:351 __mem_cgroup_uncharge_folios+0xf0/0x1c0 mm/memcontrol.c:4796 mem_cgroup_uncharge_folios include/linux/memcontrol.h:670 [inline] folios_put_refs+0x551/0x640 mm/swap.c:991 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1125 shmem_truncate_range mm/shmem.c:1237 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365 evict+0x501/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:660 dput+0x19f/0x2b0 fs/dcache.c:902 __fput+0x68e/0xa70 fs/file_table.c:473 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8d6/0x2550 kernel/exit.c:953 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x95/0x780 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:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f528158e969 RSP: 002b:00007f527f3f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000054 RBX: 00007f52817b6160 RCX: 00007f528158e969 RDX: 0000000000000080 RSI: 0000200000000040 RDI: 0000000000000009 RBP: 00007f5281610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f52817b6160 R15: 00007ffc85488538 rcu: rcu_preempt kthread starved for 10712 jiffies! g116037 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:27304 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc5-syzkaller-00277-g345030986df8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: cc cc cc cc 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 03 0b 19 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: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: d2228d81eeafe300 RBX: ffffffff81974e28 RCX: d2228d81eeafe300 RDX: 0000000000000001 RSI: ffffffff8d73740f RDI: ffffffff8bc0ff20 RBP: ffffffff8dc07ec0 R08: ffff8880b8832b5b R09: 1ffff1101710656b R10: dffffc0000000000 R11: ffffed101710656c R12: ffffffff8f7da970 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a48 FS: 0000000000000000(0000) GS:ffff888126100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbc5f6033fe CR3: 000000007943c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 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 rest_init+0x2de/0x300 init/main.c:743 start_kernel+0x470/0x4f0 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494 common_startup_64+0x13e/0x147