rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4534/1:b..l P7784/1:b..l rcu: (detected by 1, t=10503 jiffies, g=27021, q=179 ncpus=2) task:rm state:R running task stack:22480 pid:7784 tgid:7784 ppid:7748 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7068 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+0x0/0x7 arch/x86/lib/retpoline.S:171 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 cc cc cc cc cc <48> 8d 64 24 08 c3 cc e8 f4 ff ff ff 0f 0b cc cc cc cc cc cc cc cc RSP: 0018:ffffc9001367f1c8 EFLAGS: 00000286 RAX: 0000000000000000 RBX: ffffffff8b7fcba5 RCX: ffff88802323da00 RDX: 0000000000000000 RSI: ffffffff8b7fcba5 RDI: ffffc9001367f2c0 RBP: ffffc9001367f270 R08: ffffffff8137d242 R09: ffffffff814158df R10: 0000000000000003 R11: ffffffff8181de20 R12: ffff88802323da00 R13: ffffffff8181de20 R14: ffffc9001367f2c0 R15: ffffc9001367f1e0 srso_alias_return_thunk+0x5/0xfbef5 arch/x86/lib/retpoline.S:181 __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:302 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347 free_unref_folios+0x1f2/0xc10 mm/page_alloc.c:2536 folios_put_refs+0x93a/0xa60 mm/swap.c:1034 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:329 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x4bb/0xd60 mm/mmap.c:3280 __mmput+0x115/0x3c0 kernel/fork.c:1346 exit_mm+0x220/0x310 kernel/exit.c:569 do_exit+0x99e/0x27e0 kernel/exit.c:865 do_group_exit+0x207/0x2c0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbf42440a90 RSP: 002b:00007ffd11604ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fbf42531860 RCX: 00007fbf42440a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00007fbf42531860 R08: 00007ffd11604e70 R09: 00007ffd11604f50 R10: 00007ffd11604eb0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbf42535658 R15: 0000000000000001 task:udevd state:R running task stack:22168 pid:4534 tgid:4534 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6925 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6949 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.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:302 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347 free_unref_folios+0x1f2/0xc10 mm/page_alloc.c:2536 folios_put_refs+0x93a/0xa60 mm/swap.c:1034 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:329 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x4bb/0xd60 mm/mmap.c:3280 __mmput+0x115/0x3c0 kernel/fork.c:1346 exit_mm+0x220/0x310 kernel/exit.c:569 do_exit+0x99e/0x27e0 kernel/exit.c:865 do_group_exit+0x207/0x2c0 kernel/exit.c:1027 get_signal+0x16a1/0x1740 kernel/signal.c:2911 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+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f57db724a4b RSP: 002b:00007ffd0e300498 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 000000000000009e RBX: 000055cfe7361df0 RCX: 00007f57db724a4b RDX: 0000000000000000 RSI: 00007ffd0e3004a8 RDI: 0000000000000004 RBP: 000055cfe737fd90 R08: 0000000000000001 R09: d7a7c5ae8acf0c88 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000076 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10614 jiffies! g27021 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:25968 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f2/0x390 kernel/kthread.c:388 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: CPU: 1 PID: 5074 Comm: syz-fuzzer Not tainted 6.9.0-rc5-syzkaller-00355-g2c8159388952 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5283 Code: c9 50 e8 69 d3 0b 00 48 83 c4 08 4c 89 f7 e8 9d 38 00 00 0f 1f 44 00 00 4c 89 f7 e8 d0 52 24 0a e8 4b 94 36 00 fb 48 8b 5d c0 <48> 8d bb f0 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc RSP: 0018:ffffc90004d5f788 EFLAGS: 00000282 RAX: f50039f73bca3800 RBX: ffff888019765a00 RCX: ffffffff9472d603 RDX: dffffc0000000000 RSI: ffffffff8bcab8a0 RDI: ffffffff8c1f7ee0 RBP: ffffc90004d5f7d0 R08: ffffffff8fa8f92f R09: 1ffffffff1f51f25 R10: dffffc0000000000 R11: fffffbfff1f51f26 R12: 1ffff110172a7e7f R13: dffffc0000000000 R14: ffff8880b953e680 R15: ffff8880b953f3f8 FS: 000000c00005a090(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0672045f80 CR3: 00000000193ca000 CR4: 0000000000350ef0 Call Trace: context_switch kernel/sched/core.c:5412 [inline] __schedule+0x17f0/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 futex_wait_queue+0x14e/0x1d0 kernel/futex/waitwake.c:370 __futex_wait+0x17f/0x320 kernel/futex/waitwake.c:669 futex_wait+0x101/0x360 kernel/futex/waitwake.c:697 do_futex+0x33b/0x560 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x472d43 Code: 24 20 c3 cc cc cc cc 48 8b 7c 24 08 8b 74 24 10 8b 54 24 14 4c 8b 54 24 18 4c 8b 44 24 20 44 8b 4c 24 28 b8 ca 00 00 00 0f 05 <89> 44 24 30 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc RSP: 002b:000000c00006be80 EFLAGS: 00000206 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000472d43 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000002518cc0 RBP: 000000c00006bec8 R08: 0000000000000000 R09: 0000000000000000 R10: 000000c00006beb8 R11: 0000000000000206 R12: 000000c00006beb8 R13: 000000c0006cb000 R14: 000000c0000064e0 R15: 0000000000000007