rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5545/1:b..l rcu: (detected by 0, t=10502 jiffies, g=8597, q=436953 ncpus=2) task:syz.4.59 state:R running task stack:23168 pid:5545 tgid:5542 ppid:5240 flags:0x00000004 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:ffffc90009636d00 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920012c6db2 RCX: ffffc90009636d03 RDX: 0000000000000001 RSI: ffffffff8c0adc40 RDI: ffffffff8c60fb20 RBP: ffffc90009636e30 R08: ffffffff901d11af R09: 1ffffffff203a235 R10: dffffc0000000000 R11: fffffbfff203a236 R12: 1ffff920012c6dac R13: 0000000000000246 R14: ffffc90009636d90 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] blk_cgroup_congested+0x1eb/0x200 block/blk-cgroup.c:2199 __folio_throttle_swaprate+0x84/0x1d0 mm/swapfile.c:3990 folio_throttle_swaprate include/linux/swap.h:645 [inline] shmem_add_to_page_cache+0x816/0x1690 mm/shmem.c:801 shmem_alloc_and_add_folio+0x96a/0x13d0 mm/shmem.c:1839 shmem_get_folio_gfp+0x5a9/0x20a0 mm/shmem.c:2335 shmem_fault+0x253/0x6f0 mm/shmem.c:2536 __do_fault+0x135/0x460 mm/memory.c:4876 do_read_fault mm/memory.c:5282 [inline] do_fault mm/memory.c:5416 [inline] do_pte_missing mm/memory.c:3965 [inline] handle_pte_fault+0x2d1c/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: 0033:0x7f62b297dff9 RSP: 002b:00007f62b374c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f62b2b36130 RCX: 00007f62b297dff9 RDX: 000000000200000d RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f62b29f0296 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000004008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f62b2b36130 R15: 00007ffda8a3f248 rcu: rcu_preempt kthread starved for 8150 jiffies! g8597 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:25712 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: 5241 Comm: kworker/0:4 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:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 04 3b 9d 0c 48 89 de 5b e9 c3 c7 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 00 d8 03 00 65 8b 15 a0 f0 RSP: 0018:ffffc90000007518 EFLAGS: 00000293 RAX: 0000000000000100 RBX: 0000000000000001 RCX: ffff888069238000 RDX: ffff888069238000 RSI: 0000000000000001 RDI: 0000000000000005 RBP: ffffc90000007708 R08: ffffffff8a4d6213 R09: 0000000000000000 R10: ffffc90000007680 R11: fffff52000000ed4 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff88807f282800 R15: ffff88821b8fd140 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000669e0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ipt_do_table+0x401/0x1860 net/ipv4/netfilter/ip_tables.c:275 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