rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5551/1:b..l rcu: (detected by 0, t=10503 jiffies, g=21029, q=1519215 ncpus=2) task:syz-executor state:R running task stack:20992 pid:5551 tgid:5551 ppid:5547 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6997 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:unwind_get_return_address+0x6/0x90 arch/x86/kernel/unwind_orc.c:365 Code: e9 dd fe ff ff e8 da f0 83 0a 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 48 89 fb 49 be 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 RSP: 0018:ffffc90004ef7190 EFLAGS: 00000202 RAX: ffffc90004ef7230 RBX: ffffc90004ef71a0 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffc90004ef0000 RDI: ffffc90004ef71a0 RBP: ffffc90004ef7230 R08: ffffc90004ef7230 R09: ffffc90004ef71f0 R10: dffffc0000000000 R11: fffff520009dee40 R12: ffff888079511e00 R13: ffffffff81808f50 R14: ffffc90004ef7280 R15: 0000000000000000 arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __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:1108 [inline] free_unref_folios+0xf12/0x18d0 mm/page_alloc.c:2686 folios_put_refs+0x76c/0x860 mm/swap.c:1007 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x64c/0x1cf0 mm/shmem.c:1032 shmem_truncate_range mm/shmem.c:1144 [inline] shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1272 evict+0x4ea/0x9b0 fs/inode.c:723 __dentry_kill+0x20d/0x630 fs/dcache.c:615 dput+0x19f/0x2b0 fs/dcache.c:857 __fput+0x5d2/0x880 fs/file_table.c:439 task_work_run+0x251/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2dae77cc8a RSP: 002b:00007ffe87f33320 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f2dae77cc8a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffe87f3336c R08: 0000000000000000 R09: 00007ffe87f33087 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000030 R13: 0000000000039563 R14: 0000000000039563 R15: 00007ffe87f333c0 rcu: rcu_preempt kthread starved for 942 jiffies! g21029 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:25328 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 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 CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:ip_finish_output2+0x604/0x1390 net/ipv4/ip_output.c:231 Code: 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 e3 0b 00 00 41 8b 34 24 4c 89 ff e8 a9 0d 00 00 49 89 c7 41 b4 01 49 81 ff 00 f0 ff ff <76> 39 e8 a5 ee a2 01 89 c3 31 ff 89 c6 e8 1a 81 72 f7 85 db 0f 84 RSP: 0018:ffffc900001e6ca0 EFLAGS: 00000287 RAX: ffff888026ad9800 RBX: ffff8881f8cc1800 RCX: ffff88801d6e8000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900001e6de0 R08: ffffffff8a226ecc R09: ffffffff8a225e79 R10: 0000000000000002 R11: ffff88801d6e8000 R12: dffffc0000000001 R13: ffffffff8a225d1f R14: ffffffff8a225d1f R15: ffff888026ad9800 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3343a8 CR3: 000000000e734000 CR4: 0000000000350ef0 Call Trace: synproxy_send_client_synack+0x8b8/0xf30 net/netfilter/nf_synproxy_core.c:484 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+0x4af/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+0xc5/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a6/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcd/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x546/0xa30 kernel/smpboot.c:164 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