rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3847/1:b..l P3651/1:b..l (detected by 1, t=10502 jiffies, g=5977, q=150) task:kworker/u4:2 state:R running task stack:24736 pid: 3651 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:1119 [inline] RIP: 0010:rcu_is_watching+0x0/0xa0 kernel/rcu/tree.c:1122 Code: 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 ba 04 c9 08 41 f7 c4 00 02 00 00 75 b4 eb b3 e8 9a 04 c9 08 66 2e 0f 1f 84 00 00 00 00 00 <41> 57 41 56 53 65 ff 05 ec 56 97 7e e8 3f 18 c9 08 89 c3 83 f8 08 RSP: 0018:ffffc90002f37bf0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff888022fbd998 RCX: ffff888026d43b80 RDX: ffff888026d43b80 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff8a112e51 R09: fffffbfff20e2219 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000333 R13: dffffc0000000000 R14: ffff8880742fcc80 R15: ffff88801bbccfc0 rcu_read_lock include/linux/rcupdate.h:740 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0xda/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 task:syz.0.30 state:R running task stack:25824 pid: 3847 ppid: 3611 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6549 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6574 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock_irq+0x3c/0x40 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+0x9f7/0xae0 drivers/block/loop.c:2201 __blk_mq_issue_directly block/blk-mq.c:2008 [inline] __blk_mq_try_issue_directly+0x541/0x8b0 block/blk-mq.c:2064 blk_mq_try_issue_directly+0x116/0x370 block/blk-mq.c:2095 blk_mq_submit_bio+0x11bb/0x1c40 block/blk-mq.c:2317 __submit_bio+0x813/0x850 block/blk-core.c:917 __submit_bio_noacct_mq block/blk-core.c:997 [inline] submit_bio_noacct+0x955/0xb30 block/blk-core.c:1027 submit_bio+0x2dd/0x560 block/blk-core.c:1089 submit_bh fs/buffer.c:3062 [inline] __bread_slow fs/buffer.c:1180 [inline] __bread_gfp+0x1c2/0x390 fs/buffer.c:1384 sb_bread include/linux/buffer_head.h:337 [inline] __exfat_ent_get fs/exfat/fatent.c:47 [inline] exfat_ent_get+0x149/0x400 fs/exfat/fatent.c:96 exfat_count_num_clusters+0x1d4/0x3e0 fs/exfat/fatent.c:460 exfat_read_root fs/exfat/super.c:350 [inline] exfat_fill_super+0x1701/0x2d70 fs/exfat/super.c:679 get_tree_bdev+0x3fe/0x620 fs/super.c:1323 vfs_get_tree+0x88/0x270 fs/super.c:1528 do_new_mount+0x2ba/0xb40 fs/namespace.c:3005 do_mount fs/namespace.c:3348 [inline] __do_sys_mount fs/namespace.c:3556 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3533 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f81afa7c69a RSP: 002b:00007f81adef3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f81adef3ef0 RCX: 00007f81afa7c69a RDX: 0000000020006c00 RSI: 0000000020001b40 RDI: 00007f81adef3eb0 RBP: 0000000020006c00 R08: 00007f81adef3ef0 R09: 00000000208008de R10: 00000000208008de R11: 0000000000000246 R12: 0000000020001b40 R13: 00007f81adef3eb0 R14: 0000000000001503 R15: 0000000020001b80 rcu: rcu_preempt kthread timer wakeup didn't happen for 10532 jiffies! g5977 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=4205 rcu: rcu_preempt kthread starved for 10538 jiffies! g5977 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27064 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562 sched: RT throttling activated