rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7865/1:b..l P5168/1:b..l rcu: (detected by 1, t=10503 jiffies, g=27481, q=1264598 ncpus=2) task:jbd2/sda1-8 state:R running task stack:24368 pid:5168 tgid:5168 ppid:2 task_flags:0x240040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087 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:jhash2 include/linux/jhash.h:139 [inline] RIP: 0010:hash_stack lib/stackdepot.c:514 [inline] RIP: 0010:stack_depot_save_flags+0x13b/0x940 lib/stackdepot.c:614 Code: 44 31 f0 44 89 f1 c1 c1 0b 29 c8 89 c1 c1 c1 19 31 c3 29 cb 41 31 de 89 d9 c1 c1 10 41 29 ce 44 31 f0 44 89 f1 c1 c1 04 29 c8 <31> c3 c1 c0 0e 29 c3 41 31 de c1 c3 18 41 29 de 48 8b 05 2e 19 6a RSP: 0018:ffffc900106a7230 EFLAGS: 00000282 RAX: 00000000905440b9 RBX: 00000000d6c9bad6 RCX: 0000000020b5a165 RDX: ffffc900106a734c RSI: 0000000000000003 RDI: 000000005109edf8 RBP: 000000003fc51384 R08: ffffc900106a72e0 R09: 000000000000000f R10: ffffc900106a7170 R11: ffffffff81ad4ae0 R12: dffffc0000000000 R13: 1ffff920020d4e58 R14: 00000000520b5a16 R15: 1ffff1100f9e20b2 save_stack+0x109/0x1f0 mm/page_owner.c:157 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171 alloc_buffer_head+0x2a/0x290 fs/buffer.c:3015 jbd2_journal_write_metadata_buffer+0xc5/0xd80 fs/jbd2/journal.c:348 jbd2_journal_commit_transaction+0x19e4/0x61b0 fs/jbd2/commit.c:663 kjournald2+0x41c/0x7b0 fs/jbd2/journal.c:201 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 task:syz-executor state:R running task stack:22848 pid:7865 tgid:7865 ppid:5824 task_flags:0x40050c flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1772 [inline] zap_pmd_range mm/memory.c:1834 [inline] zap_pud_range mm/memory.c:1863 [inline] zap_p4d_range mm/memory.c:1884 [inline] unmap_page_range+0x3a0d/0x4510 mm/memory.c:1905 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1995 exit_mmap+0x283/0xd40 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1356 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 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+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe8417833d7 RSP: 002b:00007ffd182952d0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000000000001ed0 RCX: 00007fe8417833d7 RDX: 0000000040000000 RSI: 00007ffd1829530c RDI: 00000000ffffffff RBP: 00007ffd1829530c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10226 jiffies! g27481 f0x2 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:25752 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:stack_trace_consume_entry+0xf5/0x280 kernel/stacktrace.c:93 Code: 00 fc ff df 48 8b 1b 45 8d 70 01 41 0f b6 04 17 84 c0 0f 85 31 01 00 00 45 89 31 4a 8d 1c c3 48 89 d8 48 c1 e8 03 80 3c 10 00 <74> 1a 4d 89 cf 48 89 df 49 89 d6 49 89 f5 e8 78 af 7b 00 4d 89 f9 RSP: 0018:ffffc90000a179f0 EFLAGS: 00000246 RAX: 1ffff92000142f8b RBX: ffffc90000a17c58 RCX: ffffffff919df000 RDX: dffffc0000000000 RSI: ffffffff81834b09 RDI: ffffc90000a17b2c RBP: ffffc90000a17b28 R08: 0000000000000013 R09: ffffc90000a17b30 R10: ffffc90000a17a90 R11: ffffffff81ad4ae0 R12: 1ffff92000142f65 R13: 1ffff92000142f65 R14: 0000000000000014 R15: 1ffff92000142f66 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff66a44aea9 CR3: 0000000024966000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x10e/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4216 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:515 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:606 alloc_skb include/linux/skbuff.h:1331 [inline] synproxy_send_client_synack+0x1b9/0xe20 net/netfilter/nf_synproxy_core.c:460 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5893 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:6006 process_backlog+0x662/0x15b0 net/core/dev.c:6354 __napi_poll+0xcb/0x490 net/core/dev.c:7188 napi_poll net/core/dev.c:7257 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7379 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 80 d6 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 05 f2 81 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d08 EFLAGS: 00000246 RAX: ffff88801daf0000 RBX: ffff88802169c864 RCX: 00000000000abac1 RDX: 0000000000000001 RSI: ffff88802169c800 RDI: ffff88802169c864 RBP: 000000000003aab8 R08: ffff8880b873799b R09: 1ffff110170e6f33 R10: dffffc0000000000 R11: ffffffff8c089010 R12: ffff88801fbbc000 R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff8f337ea0 acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:699 cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:389 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x372/0x5c0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 start_secondary+0x102/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147