rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=b06c/1/0x4000000000000000 softirq=70449/70450 fqs=4 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1014/1:b..l rcu: (detected by 1, t=10502 jiffies, g=114273, q=113 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 32266 Comm: kworker/u4:5 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x19/0xb0 kernel/rcu/tree.c:700 Code: 09 65 8a 05 45 7e 93 7e 0f b6 c0 c3 0f 1f 44 00 00 f3 0f 1e fa 55 53 65 ff 05 8b 63 93 7e e8 7e ba 1d 09 48 c7 c3 68 6f 03 00 <83> f8 07 89 c5 77 7a 48 8d 3c ed 60 8a a9 8c 48 b8 00 00 00 00 00 RSP: 0018:ffffc90000007608 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 0000000000036f68 RCX: ffffffff81687655 RDX: fffffbfff1e75d5b RSI: ffffffff8b2fd2c0 RDI: ffffffff8b2fd300 RBP: 1ffff92000000ec6 R08: 0000000000000000 R09: fffffbfff1e75d5a R10: ffffffff8f3aead7 R11: 0000000000000003 R12: ffffffff8d1acba0 R13: ffff88802a66ac00 R14: ffff88807f5e7340 R15: ffff88802a66b000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f921000 CR3: 00000000457fe000 CR4: 0000000000350ef0 Call Trace: trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4bf/0x690 kernel/locking/lockdep.c:5765 rcu_lock_release include/linux/rcupdate.h:308 [inline] rcu_read_unlock include/linux/rcupdate.h:783 [inline] advance_sched+0x6dc/0xc60 net/sched/sch_taprio.c:998 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x203/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x105/0x400 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x43/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:696 Code: 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 c7 c7 40 47 ce 8a e8 c0 ba 1d 09 65 8a 05 45 7e 93 7e 0f b6 c0 c3 0f 1f 44 00 00 0f 1e fa 55 53 65 ff 05 8b 63 93 7e e8 7e ba 1d 09 48 c7 c3 68 RSP: 0018:ffffc90000007a18 EFLAGS: 00000297 RAX: 0000000000000000 RBX: ffff88803298a140 RCX: ffffffff8873b490 RDX: ffff888079209dc0 RSI: ffffffff8873b52f RDI: ffff888017a8f000 RBP: ffffc90000007a70 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000003 R12: 0000000000000000 R13: 0000000000000001 R14: ffff888017a8f000 R15: 0000000000000000 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x25f/0x350 mm/slub.c:4362 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:1051 __kfree_skb net/core/skbuff.c:1109 [inline] kfree_skb_reason+0x13a/0x210 net/core/skbuff.c:1144 __netif_receive_skb_core.constprop.0+0x565/0x3f50 net/core/dev.c:5508 __netif_receive_skb_one_core+0xaf/0x180 net/core/dev.c:5532 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5648 process_backlog+0x101/0x6b0 net/core/dev.c:5976 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6576 napi_poll net/core/dev.c:6645 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6778 __do_softirq+0x21a/0x8de kernel/softirq.c:553 do_softirq kernel/softirq.c:454 [inline] do_softirq+0xaa/0xe0 kernel/softirq.c:441 __local_bh_enable_ip+0xfc/0x120 kernel/softirq.c:381 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:820 [inline] __dev_queue_xmit+0x871/0x3ed0 net/core/dev.c:4378 dev_queue_xmit include/linux/netdevice.h:3171 [inline] batadv_send_skb_packet+0x520/0x6b0 net/batman-adv/send.c:108 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x708/0x8c0 net/batman-adv/bat_iv_ogm.c:1700 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 task:kworker/0:1H state:R running task stack:27232 pid:1014 tgid:1014 ppid:2 flags:0x00004000 Workqueue: kblockd blk_mq_requeue_work Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6904 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] loop_queue_work drivers/block/loop.c:894 [inline] loop_queue_rq+0x5ef/0x1210 drivers/block/loop.c:1876 blk_mq_dispatch_rq_list+0x449/0x2010 block/blk-mq.c:2071 __blk_mq_sched_dispatch_requests+0x680/0x1610 block/blk-mq-sched.c:315 blk_mq_sched_dispatch_requests+0xd4/0x150 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x645/0x9a0 block/blk-mq.c:2286 blk_mq_run_hw_queues+0x113/0x290 block/blk-mq.c:2335 blk_mq_requeue_work+0x64c/0x8d0 block/blk-mq.c:1504 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: rcu_preempt kthread starved for 10494 jiffies! g114273 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:25792 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6817 schedule_timeout+0x137/0x290 kernel/time/timer.c:2183 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1830 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x4e4/0x1550 kernel/smp.c:855 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 7e c5 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 24 0e 00 00 8b 43 08 31 RSP: 0018:ffffc90000107930 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9844940 RCX: ffffffff817c5d08 RDX: ffff8880156a3b80 RSI: ffffffff817c5ce2 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed1017308929 R13: 0000000000000001 R14: ffff8880b9844948 R15: ffff8880b993de80 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000203ba030 CR3: 000000000cf78000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2087 [inline] text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2297 text_poke_flush arch/x86/kernel/alternative.c:2488 [inline] text_poke_flush arch/x86/kernel/alternative.c:2485 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2495 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:826 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:818 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242