rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6118/1:b..l P5234/1:b..l rcu: (detected by 0, t=10503 jiffies, g=11577, q=840028 ncpus=2) task:syz-executor state:R running task stack:19376 pid:5234 tgid:5234 ppid:5232 flags:0x00004002 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:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5850 Code: 3c 3b 00 74 08 4c 89 f7 e8 85 14 8e 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc90003c46d00 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000788db2 RCX: ffffc90003c46d03 RDX: 0000000000000004 RSI: ffffffff8c0adc40 RDI: ffffffff8c60fb20 RBP: ffffc90003c46e40 R08: ffffffff901d11af R09: 1ffffffff203a235 R10: dffffc0000000000 R11: fffffbfff203a236 R12: 1ffff92000788dac R13: 0000000000000246 R14: ffffc90003c46d90 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] page_ext_put+0xa3/0xc0 mm/page_ext.c:550 __reset_page_owner+0x2de/0x430 mm/page_owner.c:300 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_noprof+0x135/0x2a0 mm/slub.c:4141 ptlock_alloc+0x20/0x70 mm/memory.c:6902 ptlock_init include/linux/mm.h:2958 [inline] pagetable_pte_ctor include/linux/mm.h:2985 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:73 [inline] pte_alloc_one+0xcd/0x5d0 arch/x86/mm/pgtable.c:33 __pte_alloc+0x79/0x390 mm/memory.c:448 copy_pte_range mm/memory.c:1108 [inline] copy_pmd_range+0x7d87/0x85f0 mm/memory.c:1255 copy_pud_range mm/memory.c:1292 [inline] copy_p4d_range mm/memory.c:1316 [inline] copy_page_range+0x99f/0xe90 mm/memory.c:1414 dup_mmap kernel/fork.c:750 [inline] dup_mm kernel/fork.c:1674 [inline] copy_mm+0x11fb/0x1f40 kernel/fork.c:1723 copy_process+0x1845/0x3d50 kernel/fork.c:2372 kernel_clone+0x226/0x8f0 kernel/fork.c:2784 __do_sys_clone kernel/fork.c:2927 [inline] __se_sys_clone kernel/fork.c:2911 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2911 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: 0033:0x7efd35b74853 RSP: 002b:00007ffc1cb766a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efd35b74853 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000555556e147d0 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000001a360 R14: 000000000001a271 R15: 00007ffc1cb76830 task:syz.1.238 state:R running task stack:23808 pid:6118 tgid:6118 ppid:5235 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:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline] RIP: 0010:lock_acquire+0x180/0x550 kernel/locking/lockdep.c:5821 Code: 8d bc 24 80 00 00 00 4c 89 fb 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 ff e8 4d 41 8e 00 48 c7 84 24 80 00 00 00 00 00 00 00 9c <8f> 84 24 80 00 00 00 42 80 3c 2b 00 74 08 4c 89 ff e8 3a 40 8e 00 RSP: 0018:ffffc90017b27298 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92002f64e64 RCX: ffffffff817056d4 RDX: 0000000000000000 RSI: ffffffff8c60fb00 RDI: ffffffff8c60fac0 RBP: ffffc90017b273f8 R08: ffffffff901d11af R09: 1ffffffff203a235 R10: dffffc0000000000 R11: fffffbfff203a236 R12: 1ffff92002f64e5c R13: dffffc0000000000 R14: 0000000000000000 R15: ffffc90017b27320 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __reset_page_owner+0x30/0x430 mm/page_owner.c:290 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_noprof+0x135/0x2a0 mm/slub.c:4141 vm_area_dup+0x27/0x290 kernel/fork.c:487 __split_vma+0x1cb/0xc50 mm/vma.c:384 split_vma mm/vma.c:460 [inline] vma_modify+0x153a/0x1a80 mm/vma.c:1433 vma_modify_flags+0x3a9/0x420 mm/vma.c:1451 mprotect_fixup+0x45a/0xaa0 mm/mprotect.c:664 do_mprotect_pkey+0x8e0/0xd80 mm/mprotect.c:838 __do_sys_mprotect mm/mprotect.c:859 [inline] __se_sys_mprotect mm/mprotect.c:856 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:856 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: 0033:0x7f28e137e0b7 RSP: 002b:00007fffed498ed8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a RAX: ffffffffffffffda RBX: 00007f28e0dde6c0 RCX: 00007f28e137e0b7 RDX: 0000000000000003 RSI: 0000000000020000 RDI: 00007f28e0dbf000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000021000 R11: 0000000000000206 R12: 00007fffed499030 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10573 jiffies! g11577 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:25744 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5279 Comm: kworker/1:3 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__unwind_start+0x68/0x740 arch/x86/kernel/unwind_orc.c:691 Code: 89 ef 49 c1 ef 03 41 80 3c 2f 00 74 12 4c 89 ef e8 4d 0a bd 00 48 ba 00 00 00 00 00 fc ff df 49 89 5d 00 80 3d b1 90 f0 0c 01 <75> 2f 65 48 8b 04 25 00 d8 03 00 48 39 d8 74 68 48 8d 6b 34 48 89 RSP: 0018:ffffc90000a17740 EFLAGS: 00000246 RAX: ffffc90000a177a0 RBX: ffff88802d861e00 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc90000a17800 RBP: dffffc0000000000 R08: ffffc90000a177ff R09: 0000000000000000 R10: ffffc90000a177a0 R11: fffff52000142f00 R12: 0000000000000000 R13: ffffc90000a177c8 R14: ffffc90000a177a0 R15: 1ffff92000142ef9 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa68ab35f84 CR3: 0000000031450000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24 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:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 dst_alloc+0x12b/0x190 net/core/dst.c:89 rt_dst_alloc net/ipv4/route.c:1612 [inline] __mkroute_output net/ipv4/route.c:2571 [inline] ip_route_output_key_hash_rcu+0x13cc/0x2390 net/ipv4/route.c:2793 ip_route_output_key_hash+0x193/0x2b0 net/ipv4/route.c:2622 __ip_route_output_key include/net/route.h:141 [inline] ip_route_output_flow+0x29/0x140 net/ipv4/route.c:2850 ip_route_output_key include/net/route.h:151 [inline] ip_route_me_harder+0x877/0x1360 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:5668 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5781 process_backlog+0x662/0x15b0 net/core/dev.c:6113 __napi_poll+0xcb/0x490 net/core/dev.c:6834 napi_poll net/core/dev.c:6903 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7025 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 TCP: request_sock_subflow_v4: Possible SYN flooding on port [::]:20002. 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