rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7261/1:b..l rcu: (detected by 0, t=10502 jiffies, g=22793, q=761 ncpus=2) task:syz.2.471 state:R running task stack:23168 pid:7261 tgid:7258 ppid:6029 flags:0x00004006 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:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:395 [inline] RIP: 0010:__rcu_read_unlock+0x34/0x110 kernel/rcu/tree_plugin.h:434 Code: 55 41 54 53 49 bc 00 00 00 00 00 fc ff df 65 4c 8b 34 25 00 d8 03 00 4d 8d ae 44 04 00 00 4c 89 eb 48 c1 eb 03 42 0f b6 04 23 <84> c0 75 6b 41 8b 6d 00 ff cd 42 0f b6 04 23 84 c0 75 76 41 89 6d RSP: 0018:ffffc9000de8f228 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: 1ffff11005af8448 RCX: ffffc9000de8f103 RDX: 0000000000000001 RSI: ffffffff8c0adc40 RDI: ffffffff8c60fb20 RBP: ffffc9000de8f3f0 R08: ffffffff901d11af R09: 1ffffffff203a235 R10: dffffc0000000000 R11: fffffbfff203a236 R12: dffffc0000000000 R13: ffff88802d7c2244 R14: ffff88802d7c1e00 R15: 0000000000000001 rcu_read_unlock include/linux/rcupdate.h:882 [inline] pte_unmap include/linux/pgtable.h:115 [inline] finish_fault+0xf0f/0x1480 mm/memory.c:5152 do_read_fault mm/memory.c:5286 [inline] do_fault mm/memory.c:5416 [inline] do_pte_missing mm/memory.c:3965 [inline] handle_pte_fault+0x2d44/0x6800 mm/memory.c:5751 __handle_mm_fault mm/memory.c:5894 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6062 faultin_page mm/gup.c:1187 [inline] __get_user_pages+0x1b16/0x48d0 mm/gup.c:1485 populate_vma_page_range+0x264/0x330 mm/gup.c:1923 __mm_populate+0x27a/0x460 mm/gup.c:2026 mm_populate include/linux/mm.h:3371 [inline] vm_mmap_pgoff+0x2c3/0x3d0 mm/util.c:593 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: 0033:0x7fcb0817dff9 RSP: 002b:00007fcb08ffd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fcb08336058 RCX: 00007fcb0817dff9 RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007fcb081f0296 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fcb08336058 R15: 00007ffed78b7218 rcu: rcu_preempt kthread starved for 9890 jiffies! g22793 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:24912 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: 0 UID: 0 PID: 8 Comm: kworker/0:0 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:seqcount_lockdep_reader_access+0x1e0/0x220 include/linux/seqlock.h:75 Code: 00 4d 85 ed 75 16 e8 bf 58 12 00 eb 15 e8 b8 58 12 00 e8 f3 58 44 0a 4d 85 ed 74 ea e8 a9 58 12 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00 RSP: 0018:ffffc900000061e0 EFLAGS: 00000246 RAX: ffffffff81828ea7 RBX: 0000000000000000 RCX: ffff88801cafda00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000006298 R08: ffffffff81828e7d R09: 1ffffffff285991d R10: dffffc0000000000 R11: fffffbfff285991e R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000046 R15: 1ffff92000000c3c FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7367c9077a CR3: 0000000024aae000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ktime_get_with_offset+0x83/0x150 kernel/time/timekeeping.c:891 ktime_get_real include/linux/timekeeping.h:82 [inline] net_timestamp_set net/core/dev.c:2169 [inline] dev_queue_xmit_nit+0x966/0xc10 net/core/dev.c:2319 xmit_one net/core/dev.c:3586 [inline] dev_hard_start_xmit+0x15f/0x7e0 net/core/dev.c:3606 __dev_queue_xmit+0x1b56/0x3f30 net/core/dev.c:4430 dev_queue_xmit include/linux/netdevice.h:3154 [inline] br_dev_queue_push_xmit+0x703/0x8d0 net/bridge/br_forward.c:53 NF_HOOK+0x700/0x7c0 include/linux/netfilter.h:314 br_nf_post_routing+0xa20/0xe80 net/bridge/br_netfilter_hooks.c:996 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+0x2a7/0x460 include/linux/netfilter.h:312 br_forward_finish+0xd8/0x130 net/bridge/br_forward.c:66 br_nf_forward_finish+0xb49/0xfb0 net/bridge/br_netfilter_hooks.c:692 NF_HOOK+0x700/0x7c0 include/linux/netfilter.h:314 br_nf_forward_ip+0x61e/0x7b0 net/bridge/br_netfilter_hooks.c:746 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+0x2a7/0x460 include/linux/netfilter.h:312 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 br_handle_frame_finish+0x18ba/0x1fe0 net/bridge/br_input.c:215 br_nf_hook_thresh+0x472/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x12f/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