rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P53/1:b..l rcu: (detected by 1, t=10503 jiffies, g=17645, q=1432854 ncpus=2) task:kworker/u8:3 state:R running task stack:24560 pid:53 tgid:53 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5730 kernel/sched/core.c:6690 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7012 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:62 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x51/0x1a0 mm/kasan/generic.c:189 Code: ff 7f ff ff 48 39 f8 0f 83 b3 00 00 00 4c 8d 54 37 ff 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1 e9 03 <48> 01 c5 49 01 c1 48 89 e8 49 8d 59 01 48 89 da 48 29 ea 48 83 fa RSP: 0018:ffffc90000be6fb0 EFLAGS: 00000a02 RAX: dffffc0000000000 RBX: ffff88801d42f898 RCX: ffffffff81fb1d13 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88801d42f898 RBP: 1ffff11003a85f13 R08: 0000000000000000 R09: 1ffff11003a85f13 R10: ffff88801d42f89b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] __page_table_check_zero+0x163/0x360 mm/page_table_check.c:156 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1109 [inline] free_unref_page+0x5e5/0xdc0 mm/page_alloc.c:2638 __put_partials+0x14c/0x170 mm/slub.c:3145 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4141 ext4_alloc_io_end_vec+0x2b/0x1c0 fs/ext4/page-io.c:60 mpage_map_and_submit_extent fs/ext4/inode.c:2256 [inline] ext4_do_writepages+0x130c/0x2fe0 fs/ext4/inode.c:2724 ext4_writepages+0x303/0x730 fs/ext4/inode.c:2813 do_writepages+0x1a3/0x7f0 mm/page-writeback.c:2683 __writeback_single_inode+0x166/0xfa0 fs/fs-writeback.c:1658 writeback_sb_inodes+0x603/0xfa0 fs/fs-writeback.c:1954 __writeback_inodes_wb+0xff/0x2e0 fs/fs-writeback.c:2025 wb_writeback+0x721/0xb50 fs/fs-writeback.c:2136 wb_check_old_data_flush fs/fs-writeback.c:2240 [inline] wb_do_writeback fs/fs-writeback.c:2293 [inline] wb_workfn+0x8c3/0xbc0 fs/fs-writeback.c:2321 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10438 jiffies! g17645 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:27120 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5730 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:nf_nat_ipv4_local_fn net/netfilter/nf_nat_proto.c:809 [inline] RIP: 0010:nf_nat_ipv4_local_fn+0x25d/0x550 net/netfilter/nf_nat_proto.c:792 Code: 6b c6 38 44 89 ee bf 02 00 00 00 44 8b 7c 05 74 e8 b8 6b 42 f8 41 83 fd 02 41 0f 96 c5 45 0f b6 ed 49 6b c5 38 48 8d 7c 05 60 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 RSP: 0018:ffffc900001e7150 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff88820df633c0 RCX: ffffffff894b1588 RDX: ffff88801d6f8000 RSI: 0000000000000002 RDI: ffff88802e798360 RBP: ffff88802e798300 R08: 0000000000000005 R09: 0000000000000002 R10: 0000000000000003 R11: 0000000000000000 R12: ffffc900001e7228 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d797052d8 CR3: 000000000df7c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook+0x386/0x6d0 include/linux/netfilter.h:269 __ip_local_out+0x339/0x640 net/ipv4/ip_output.c:119 ip_local_out+0x2a/0x4a0 net/ipv4/ip_output.c:128 synproxy_send_tcp.isra.0+0x439/0x630 net/netfilter/nf_synproxy_core.c:439 synproxy_send_client_synack+0x94c/0xcf0 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] nft_synproxy_do_eval+0xa49/0xd60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x2e6/0x18f0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x18b/0x350 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook.constprop.0+0x42e/0x750 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5666 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5779 process_backlog+0x443/0x15f0 net/core/dev.c:6111 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6966 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 run_ksoftirqd kernel/softirq.c:927 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:919 smpboot_thread_fn+0x661/0xa30 kernel/smpboot.c:164 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244