syzbot

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:
 <NMI>
 </NMI>
 <IRQ>
 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 <f3> 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
 </IRQ>
 <TASK>
 __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>
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:
 <TASK>
 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
 </TASK>
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:
 <TASK>
 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
 </TASK>
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:
 <IRQ>
 </IRQ>
 <TASK>
 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
 </TASK>