rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5229/1:b..l rcu: (detected by 0, t=10503 jiffies, g=9025, q=1346766 ncpus=2) task:syz-executor214 state:R running task stack:22560 pid:5229 tgid:5229 ppid:5223 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0xed6/0x5920 kernel/sched/core.c:6675 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6997 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:lock_release+0x3e5/0x6f0 kernel/locking/lockdep.c:5830 Code: 7e 83 f8 01 0f 85 fd 01 00 00 9c 58 f6 c4 02 0f 85 e8 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 c7 43 08 00 00 00 00 48 8b 84 24 88 RSP: 0018:ffffc900037ffa58 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920006fff4d RCX: ffffc900037ffaa8 RDX: 1ffff1100577c51a RSI: ffffffff8b6ccf40 RDI: ffffffff8bd196e0 RBP: f9abc992e02c477d R08: 0000000000000000 R09: fffffbfff20be189 R10: ffffffff905f0c4f R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000002 R14: ffff88802bbe28d8 R15: ffff88802bbe1e00 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] page_ext_put+0x43/0xd0 mm/page_ext.c:550 __page_table_check_zero+0x2d7/0x360 mm/page_table_check.c:160 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:3146 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:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4142 getname_flags.part.0+0x4c/0x550 fs/namei.c:139 getname_flags+0x93/0xf0 include/linux/audit.h:322 vfs_fstatat+0x86/0x160 fs/stat.c:340 __do_sys_newfstatat+0xa2/0x130 fs/stat.c:505 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f94a740399a RSP: 002b:00007ffec2227db8 EFLAGS: 00000286 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f94a740399a RDX: 00007ffec2227de0 RSI: 00007ffec2227e70 RDI: 00000000ffffff9c RBP: 00007ffec2227e70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000286 R12: 00007ffec2228ee0 R13: 000055556f5ad7c0 R14: 00007ffec2228f20 R15: 0000000000000002 rcu: rcu_preempt kthread starved for 4150 jiffies! g9025 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:27104 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0xed6/0x5920 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6767 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: 0 UID: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.11.0-syzkaller-11558-g075dbe9f6e3c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__local_bh_enable_ip+0xac/0x120 kernel/softirq.c:389 Code: 1d 01 d0 b3 7e 65 8b 05 fa cf b3 7e a9 00 ff ff 00 74 4d bf 01 00 00 00 e8 d1 90 0b 00 e8 3c 93 44 00 fb 65 8b 05 dc cf b3 7e <85> c0 74 52 5b 5d c3 cc cc cc cc 65 8b 05 5e 7c b2 7e 85 c0 75 9e RSP: 0018:ffffc900000070c8 EFLAGS: 00000206 RAX: 0000000080000102 RBX: 00000000fffffe01 RCX: 1ffffffff2dce1d5 RDX: 0000000000000000 RSI: ffffffff8b6ccc40 RDI: ffffffff8bd196e0 RBP: ffffffff89ab4b9c R08: 0000000000000001 R09: fffffbfff2dc2ba5 R10: ffffffff96e15d2f R11: 0000000000000000 R12: 1ffff92000000e3d R13: ffff88814b43daa0 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffec2227dcc CR3: 000000007a466000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: local_bh_enable include/linux/bottom_half.h:33 [inline] ipt_do_table+0xd59/0x1aa0 net/ipv4/netfilter/ip_tables.c:357 iptable_mangle_hook+0x69/0x4b0 net/ipv4/netfilter/iptable_mangle.c:80 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 NF_HOOK_COND include/linux/netfilter.h:302 [inline] ip_output+0x1bc/0x2a0 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:450 [inline] ip_local_out+0x33e/0x4a0 net/ipv4/ip_output.c:130 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:5662 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5775 process_backlog+0x443/0x15f0 net/core/dev.c:6107 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6962 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 do_softirq kernel/softirq.c:455 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:442 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x870/0xc80 drivers/net/netdevsim/dev.c:850 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