syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5115/1:b..l
	(detected by 1, t=10502 jiffies, g=15137, q=126 ncpus=2)
task:kworker/u4:26   state:R  running task     stack:25688 pid:5115  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:101 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x5f/0x290 mm/kasan/generic.c:189
Code: eb 03 49 b8 00 00 00 00 00 fc ff df 4e 8d 0c 03 4c 8d 54 37 ff 49 c1 ea 03 49 bb 01 00 00 00 00 fc ff df 4f 8d 34 1a 4c 89 f5 <4c> 29 cd 48 83 fd 10 7f 26 48 85 ed 0f 84 3a 01 00 00 49 f7 d2 49
RSP: 0018:ffffc9001341f868 EFLAGS: 00000a07
RAX: 0000000000000001 RBX: 1ffff1100438266c RCX: ffffffff8879d78b
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888021c13364
RBP: ffffed100438266d R08: dffffc0000000000 R09: ffffed100438266c
R10: 1ffff1100438266c R11: dffffc0000000001 R12: ffff8880593a0000
R13: ffff888021c13280 R14: ffffed100438266d R15: ffffffff8879decb
 instrument_atomic_write include/linux/instrumented.h:87 [inline]
 atomic_set include/linux/atomic/atomic-instrumented.h:41 [inline]
 refcount_set include/linux/refcount.h:136 [inline]
 __build_skb_around net/core/skbuff.c:283 [inline]
 __alloc_skb+0x20b/0x670 net/core/skbuff.c:530
 __netdev_alloc_skb+0xfb/0x500 net/core/skbuff.c:579
 __netdev_alloc_skb_ip_align include/linux/skbuff.h:3215 [inline]
 netdev_alloc_skb_ip_align include/linux/skbuff.h:3225 [inline]
 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:559 [inline]
 batadv_iv_ogm_queue_add+0x6a0/0xbf0 net/batman-adv/bat_iv_ogm.c:671
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:850 [inline]
 batadv_iv_ogm_schedule+0xc49/0x1090 net/batman-adv/bat_iv_ogm.c:869
 batadv_iv_send_outstanding_bat_ogm_packet+0x6fa/0x800 net/batman-adv/bat_iv_ogm.c:1713
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: rcu_preempt kthread starved for 10394 jiffies! g15137 f0x0 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:26112 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
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:112 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572