rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4437/1:b..l P3589/1:b..l P148/1:b..l P4627/1:b..l (detected by 1, t=10502 jiffies, g=7009, q=239) task:syz.4.139 state:R running task stack: 0 pid: 4627 ppid: 3975 flags:0x00000008 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_common+0x140/0x260 kernel/sched/core.c:6552 preempt_schedule+0x64/0x84 kernel/sched/core.c:6577 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock_irq+0xf0/0x134 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:413 [inline] loop_queue_work drivers/block/loop.c:1068 [inline] loop_queue_rq+0x9b0/0xb20 drivers/block/loop.c:2201 __blk_mq_issue_directly block/blk-mq.c:2008 [inline] __blk_mq_try_issue_directly+0x40c/0x6a0 block/blk-mq.c:2064 blk_mq_try_issue_directly+0x108/0x334 block/blk-mq.c:2095 blk_mq_submit_bio+0xf40/0x1ae0 __submit_bio+0x628/0x664 block/blk-core.c:917 __submit_bio_noacct_mq block/blk-core.c:997 [inline] submit_bio_noacct+0x680/0x7dc block/blk-core.c:1027 submit_bio+0x394/0x68c block/blk-core.c:1089 submit_stripe_bio fs/btrfs/volumes.c:6789 [inline] btrfs_map_bio+0xaec/0x12e8 fs/btrfs/volumes.c:6878 btrfs_submit_metadata_bio+0x43c/0x5ac submit_one_bio fs/btrfs/extent_io.c:182 [inline] read_extent_buffer_pages+0x13e0/0x1ad0 fs/btrfs/extent_io.c:6658 btree_read_extent_buffer_pages+0xe4/0x2e0 fs/btrfs/disk-io.c:308 read_tree_block+0x70/0xb8 fs/btrfs/disk-io.c:1050 read_block_for_search+0x3f8/0x5c4 fs/btrfs/ctree.c:1498 btrfs_search_slot+0x1254/0x24d8 fs/btrfs/ctree.c:1973 btrfs_lookup_inode+0xdc/0x3c8 fs/btrfs/inode-item.c:408 btrfs_read_locked_inode fs/btrfs/inode.c:3802 [inline] btrfs_iget_path+0x2ac/0x1414 fs/btrfs/inode.c:5965 btrfs_iget+0x38/0x4c fs/btrfs/inode.c:5987 btrfs_fill_super+0x1f0/0x2c8 fs/btrfs/super.c:1393 btrfs_mount_root+0x6f8/0x7f8 fs/btrfs/super.c:1752 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611 vfs_get_tree+0x90/0x274 fs/super.c:1517 fc_mount fs/namespace.c:1000 [inline] vfs_kern_mount+0xdc/0x178 fs/namespace.c:1030 btrfs_mount+0x328/0x9b8 fs/btrfs/super.c:1812 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611 vfs_get_tree+0x90/0x274 fs/super.c:1517 do_new_mount+0x278/0x8fc fs/namespace.c:3005 path_mount+0x594/0x101c fs/namespace.c:3335 do_mount fs/namespace.c:3348 [inline] __do_sys_mount fs/namespace.c:3556 [inline] __se_sys_mount fs/namespace.c:3533 [inline] __arm64_sys_mount+0x510/0x5e0 fs/namespace.c:3533 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 task:kworker/u4:2 state:R running task stack: 0 pid: 148 ppid: 2 flags:0x00000008 Workqueue: events_power_efficient gc_worker Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6780 arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:463 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] seqcount_lockdep_reader_access+0x228/0x2cc include/linux/seqlock.h:105 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:338 [inline] gc_worker+0x2a0/0x12ac net/netfilter/nf_conntrack_core.c:1472 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 process_scheduled_works kernel/workqueue.c:2373 [inline] worker_thread+0xb88/0x1034 kernel/workqueue.c:2459 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 task:udevd state:R running task stack: 0 pid: 3589 ppid: 1 flags:0x00000004 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6780 arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:463 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 arch_local_irq_restore+0x8/0x10 arch/arm64/include/asm/irqflags.h:122 lock_is_held include/linux/lockdep.h:287 [inline] rcu_read_lock_held+0x34/0x50 kernel/rcu/update.c:311 hlist_bl_first_rcu include/linux/rculist_bl.h:24 [inline] __d_lookup+0x174/0x6a0 fs/dcache.c:2430 lookup_fast+0xcc/0x62c fs/namei.c:1621 walk_component+0xf4/0x4cc fs/namei.c:1972 link_path_walk+0x5a0/0xc38 path_openat+0x1e8/0x26cc fs/namei.c:3738 do_filp_open+0x1a8/0x3b4 fs/namei.c:3769 do_sys_openat2+0x128/0x3e0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1280 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 task:kworker/u4:9 state:R running task stack: 0 pid: 4437 ppid: 2 flags:0x00000008 Workqueue: bat_events batadv_nc_worker Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_notrace+0xc4/0x1a8 kernel/sched/core.c:6631 rcu_is_watching+0x10c/0x18c kernel/rcu/tree.c:1124 rcu_read_unlock include/linux/rcupdate.h:768 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x1ec/0x580 net/batman-adv/network-coding.c:723 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 rcu: rcu_preempt kthread timer wakeup didn't happen for 500 jiffies! g7009 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=4259 rcu: rcu_preempt kthread starved for 501 jiffies! g7009 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack: 0 pid: 15 ppid: 2 flags:0x00000008 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 schedule+0x11c/0x1c8 kernel/sched/core.c:6459 schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x26c/0x13d4 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 rcu: Stack dump where RCU GP kthread last ran: Task dump for CPU 1: task:syz.2.153 state:R running task stack: 0 pid: 4708 ppid: 3977 flags:0x00000001 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 sched_show_task+0x43c/0x574 kernel/sched/core.c:8640 dump_cpu_task+0x84/0xa8 kernel/sched/core.c:10914 rcu_check_gp_kthread_starvation+0x1f0/0x254 kernel/rcu/tree_stall.h:488 print_other_cpu_stall+0x202c/0x2290 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0x1894/0x1b8c kernel/rcu/tree.c:2619 update_process_times+0x1d4/0x270 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x340/0x4f8 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x458/0xca4 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x2c0/0xb64 kernel/time/hrtimer.c:1812 timer_handler drivers/clocksource/arm_arch_timer.c:659 [inline] arch_timer_handler_virt+0x74/0x88 drivers/clocksource/arm_arch_timer.c:670 handle_percpu_devid_irq+0x29c/0x7fc kernel/irq/chip.c:933 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq_desc kernel/irq/irqdesc.c:651 [inline] handle_domain_irq+0xec/0x178 kernel/irq/irqdesc.c:706 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:758 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x74/0x94 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] lock_acquire+0x280/0x77c kernel/locking/lockdep.c:5626 __might_fault+0xc8/0x128 mm/memory.c:5328 setup_sigframe arch/arm64/kernel/signal.c:627 [inline] setup_rt_frame arch/arm64/kernel/signal.c:789 [inline] handle_signal arch/arm64/kernel/signal.c:830 [inline] do_signal arch/arm64/kernel/signal.c:905 [inline] do_notify_resume+0xf18/0x32b8 arch/arm64/kernel/signal.c:943 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584