rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20761/1:b..l P21211/1:b..l rcu: (detected by 0, t=10502 jiffies, g=166785, q=161 ncpus=2) task:syz.3.3494 state:R running task stack:25072 pid:21211 tgid:21210 ppid:19760 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6708 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6732 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x2124/0x2a00 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_folios+0x103a/0x1b00 mm/page_alloc.c:2660 folios_put_refs+0x76e/0x860 mm/swap.c:1039 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x6de/0x1df0 mm/shmem.c:1023 shmem_truncate_range mm/shmem.c:1132 [inline] shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1260 evict+0x2aa/0x630 fs/inode.c:669 __dentry_kill+0x20d/0x630 fs/dcache.c:610 dput+0x19f/0x2b0 fs/dcache.c:852 __fput+0x5f8/0x8a0 fs/file_table.c:430 task_work_run+0x251/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x16a1/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc616977299 RSP: 002b:00007fc617686048 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: 0000000000000000 RBX: 00007fc616b05f80 RCX: 00007fc616977299 RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007fc6169e48e6 R08: 0000000000000018 R09: 0000000000000000 R10: 0000000020000200 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc616b05f80 R15: 00007fff6fe98eb8 task:syz-executor state:R running task stack:21584 pid:20761 tgid:20761 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:srso_alias_safe_ret+0x5/0x7 arch/x86/lib/retpoline.S:174 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 48 8d 64 24 08 cc e8 f4 ff ff ff 0f 0b cc cc cc cc cc cc cc cc cc cc cc cc cc RSP: 0018:ffffc90004107530 EFLAGS: 00000286 RAX: 0000000000000000 RBX: ffffffff815684cf RCX: ffff888059640000 RDX: 0000000000000000 RSI: ffffffff815684cf RDI: ffffc90004107620 RBP: ffffc900041075d0 R08: ffffffff81376b62 R09: ffffffff814120bf R10: 0000000000000003 R11: ffffffff817f0ca0 R12: ffff888059640000 R13: ffffffff817f0ca0 R14: ffffc90004107620 R15: ffffc90004107540 __pfx_stack_trace_consume_entry+0x10/0x10 arch_stack_walk+0x145/0x1b0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612 vfree+0x186/0x2e0 mm/vmalloc.c:3364 kcov_put kernel/kcov.c:429 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:525 __fput+0x24c/0x8a0 fs/file_table.c:422 task_work_run+0x251/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x16a1/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7c0197902c RSP: 002b:00007fffaf850340 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 0000000000000020 RBX: 00007f7c02634620 RCX: 00007f7c0197902c RDX: 0000000000000020 RSI: 00007f7c02634670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fffaf850394 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f7c02634670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10597 jiffies! g166785 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:25840 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111