rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7556/1:b..l rcu: (detected by 1, t=10502 jiffies, g=18433, q=243 ncpus=2) task:syz.2.458 state:R running task stack:19080 pid:7556 tgid:7556 ppid:5814 task_flags:0x40064c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1129/0x5c00 kernel/sched/core.c:6747 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6926 preempt_schedule_thunk+0x16/0x30 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:1771 [inline] zap_pmd_range mm/memory.c:1833 [inline] zap_pud_range mm/memory.c:1862 [inline] zap_p4d_range mm/memory.c:1883 [inline] unmap_page_range+0xf13/0x4420 mm/memory.c:1904 unmap_single_vma+0x19a/0x2b0 mm/memory.c:1950 unmap_vmas+0x22c/0x490 mm/memory.c:1994 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:586 [inline] do_exit+0x9c0/0x2d60 kernel/exit.c:941 do_group_exit+0xd3/0x2a0 kernel/exit.c:1103 get_signal+0x24cf/0x26a0 kernel/signal.c:3035 arch_do_signal_or_restart+0x8f/0x7d0 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:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fbe5c58d171 RSP: 002b:0000000000000030 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fbe5c7a5fa0 RCX: 00007fbe5c58d169 RDX: 0000000000000000 RSI: 0000000000000030 RDI: 0000000000000600 RBP: 00007fbe5c60e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbe5c7a5fa0 R15: 00007ffe132ee878 rcu: rcu_preempt kthread starved for 9049 jiffies! g18433 f0x0 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:28056 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1129/0x5c00 kernel/sched/core.c:6747 __schedule_loop kernel/sched/core.c:6824 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6839 schedule_timeout+0x123/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248 kthread+0x3a4/0x760 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.14.0-syzkaller-05877-g1a9239bb4253 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:ip6_packet_match net/ipv6/netfilter/ip6_tables.c:78 [inline] RIP: 0010:ip6t_do_table+0x7ff/0x1be0 net/ipv6/netfilter/ip6_tables.c:306 Code: 0f 95 c3 89 de e8 a1 71 95 f7 41 38 dd 0f 85 cc 04 00 00 e8 83 77 95 f7 48 8d b5 83 00 00 00 48 89 f0 48 89 b4 24 88 00 00 00 <83> e6 07 48 c1 e8 03 42 0f b6 04 30 40 38 f0 7f 08 84 c0 0f 85 6d RSP: 0018:ffffc90000006a00 EFLAGS: 00000246 RAX: ffff88807ca14403 RBX: 0000000000000000 RCX: ffffffff8a259baf RDX: ffffffff8e097740 RSI: ffff88807ca14403 RDI: 0000000000000000 RBP: ffff88807ca14380 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88807ca14404 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124a3d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000161000 CR3: 0000000030562000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip6table_mangle_hook+0xc3/0x770 net/ipv6/netfilter/ip6table_mangle.c:73 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook+0x471/0x7a0 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_post_routing+0x8bd/0x1190 net/bridge/br_netfilter_hooks.c:969 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook+0x45e/0x780 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] br_forward_finish+0xcd/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh+0x301/0x410 net/bridge/br_netfilter_hooks.c:1170 br_nf_forward_finish+0x66a/0xba0 net/bridge/br_netfilter_hooks.c:665 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] br_nf_forward_ip.part.0+0x609/0x810 net/bridge/br_netfilter_hooks.c:719 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:679 [inline] br_nf_forward+0xf0f/0x1be0 net/bridge/br_netfilter_hooks.c:776 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook+0x45e/0x780 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] __br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] br_flood+0x39c/0x650 net/bridge/br_forward.c:249 br_handle_frame_finish+0xe8e/0x1c20 net/bridge/br_input.c:220 br_nf_hook_thresh+0x301/0x410 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0xad5/0x14a0 net/bridge/br_input.c:433 __netif_receive_skb_core.constprop.0+0xa23/0x4a00 net/core/dev.c:5777 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5889 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6004 process_backlog+0x442/0x15e0 net/core/dev.c:6356 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7328 napi_poll net/core/dev.c:7392 [inline] net_rx_action+0xa97/0x1010 net/core/dev.c:7514 handle_softirqs+0x216/0x8e0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 50 c0 3b 08 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 48 6c 9c 00 fb f4 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e007d68 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b6252f9 RDX: 0000000000000001 RSI: ffff888021a88800 RDI: ffff888021a88864 RBP: ffff888021a88864 R08: 0000000000000001 R09: ffffed10170865bd R10: ffff8880b8432deb R11: 0000000000000000 R12: ffff888021378000 R13: ffffffff8f031580 R14: 0000000000000000 R15: 0000000000000000 acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:701 cpuidle_enter_state+0xb2/0x500 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:389 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x378/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:743 start_kernel+0x3e9/0x4d0 init/main.c:1099 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:513 x86_64_start_kernel+0xb0/0xc0 arch/x86/kernel/head64.c:494 common_startup_64+0x13e/0x148 net_ratelimit: 25277 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:56:09:ab:18:30:a6, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:56:09:ab:18:30:a6, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 28750 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:56:09:ab:18:30:a6, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:56:09:ab:18:30:a6, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)