rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5252/1:b..l P7399/1:b..l P7415/1:b..l rcu: (detected by 1, t=10503 jiffies, g=16797, q=1546172 ncpus=2) task:syz.1.979 state:R running task stack:23664 pid:7415 tgid:7413 ppid:5250 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6861 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6885 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:1691 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x36b1/0x40e0 mm/memory.c:1810 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900 exit_mmap+0x275/0xc40 mm/mmap.c:1864 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 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: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+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f210fb7dff9 RSP: 002b:00007f21108e5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: fffffffffffffe00 RBX: 00007f210fd35f80 RCX: 00007f210fb7dff9 RDX: 0000000030004001 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007f210fbf0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f210fd35f80 R15: 00007f210fe5fa28 task:syz.4.973 state:R running task stack:21240 pid:7399 tgid:7399 ppid:5249 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6861 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6885 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:1691 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x36b1/0x40e0 mm/memory.c:1810 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900 exit_mmap+0x275/0xc40 mm/mmap.c:1864 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 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: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+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3396d7dff9 RSP: 002b:00007f339705fb88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000024b63 RCX: 00007f3396d7dff9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f3396f37a80 R08: 0000000000000001 R09: 00007f339705fe7f R10: 00007f3396c00000 R11: 0000000000000246 R12: 0000000000024c14 R13: 00007f339705fc90 R14: 0000000000000032 R15: ffffffffffffffff task:syz-executor state:R running task stack:20096 pid:5252 tgid:5252 ppid:5230 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7004 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_next_frame+0x1970/0x22d0 arch/x86/kernel/unwind_orc.c:682 Code: b5 00 00 00 48 8b 44 24 20 42 0f b6 04 20 84 c0 0f 85 2d 01 00 00 41 c7 45 00 00 00 00 00 31 c0 48 81 c4 98 00 00 00 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 cc cc cc cc 4d 89 f4 4c 89 f5 4c 89 e8 48 RSP: 0018:ffffc9000386f698 EFLAGS: 00000286 RAX: 0000000080000001 RBX: ffffc9000386f6c0 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffc90003868000 RDI: 0000000000000001 RBP: ffffc9000386f6c0 R08: ffffc9000386fcd0 R09: 0000000000000000 R10: ffffc9000386f710 R11: fffff5200070dee4 R12: ffff88802a49bc00 R13: ffffc9000386f6c0 R14: ffffc90003868000 R15: ffffc9000386fce0 arch_stack_walk+0x11c/0x150 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+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_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 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:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4153 __d_alloc+0x31/0x700 fs/dcache.c:1636 d_alloc_pseudo+0x1f/0xb0 fs/dcache.c:1768 alloc_path_pseudo fs/file_table.c:337 [inline] alloc_file_pseudo+0x123/0x290 fs/file_table.c:353 sock_alloc_file+0xb8/0x280 net/socket.c:468 sock_map_fd net/socket.c:493 [inline] __sys_socket+0x1dd/0x3c0 net/socket.c:1725 __do_sys_socket net/socket.c:1730 [inline] __se_sys_socket net/socket.c:1728 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1728 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f287e77ff17 RSP: 002b:00007f287ea5f6d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f287e9052e0 RCX: 00007f287e77ff17 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 00007f287ea5fdec R08: 0000000000000000 R09: 00007f287ea5fb07 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000032 R13: 0000000000024d92 R14: 0000000000000000 R15: 00007f287ea5fe40 rcu: rcu_preempt kthread starved for 10504 jiffies! g16797 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:26144 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 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+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: 5289 Comm: kworker/1:4 Not tainted 6.12.0-rc2-syzkaller-00320-gba01565ced22 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__mkroute_output net/ipv4/route.c:2499 [inline] RIP: 0010:ip_route_output_key_hash_rcu+0xb80/0x2390 net/ipv4/route.c:2795 Code: 3c 08 00 74 08 48 89 ef e8 cd ba df f7 48 8b 5d 00 48 83 c3 6c 48 89 d8 48 c1 e8 03 48 bd 00 00 00 00 00 fc ff df 0f b6 04 28 <84> c0 0f 85 74 10 00 00 8b 1b 31 ff 89 de e8 5d 0e 76 f7 85 db 0f RSP: 0018:ffffc90000a17c18 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffff88801e77cb6c RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff8a1edc83 R09: 1ffffffff2858f00 R10: dffffc0000000000 R11: fffffbfff2858f01 R12: 0000000000000000 R13: 0000000000000000 R14: ffffc90000a17d00 R15: ffff88802539f800 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efda21e8000 CR3: 000000007c2aa000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip_route_output_key_hash+0x193/0x2b0 net/ipv4/route.c:2624 __ip_route_output_key include/net/route.h:141 [inline] ip_route_output_flow+0x29/0x140 net/ipv4/route.c:2852 ip_route_output_key include/net/route.h:151 [inline] ip_route_me_harder+0x80d/0x1300 net/ipv4/netfilter.c:53 synproxy_send_tcp+0x356/0x6c0 net/netfilter/nf_synproxy_core.c:431 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+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:5666 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __napi_poll+0xcb/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 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+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244