rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=ece/1/0x4000000000000000 softirq=35047/35047 fqs=0 
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1):
	(detected by 1, t=10502 jiffies, g=56193, q=108)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 16977 Comm: syz-executor.5 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:queued_write_lock_slowpath+0x131/0x270 kernel/locking/qrwlock.c:77
Code: 00 00 00 00 fc ff df 49 01 c7 41 83 c6 03 41 0f b6 07 41 38 c6 7c 08 84 c0 0f 85 fe 00 00 00 8b 03 3d 00 01 00 00 74 19 f3 90 <41> 0f b6 07 41 38 c6 7c ec 84 c0 74 e8 48 89 df e8 4a 75 5c 00 eb
RSP: 0018:ffffc9000c5a7a60 EFLAGS: 00000006
RAX: 0000000000000300 RBX: ffffffff8bc0a080 RCX: ffffffff8159a38a
RDX: fffffbfff1781411 RSI: 0000000000000004 RDI: ffffffff8bc0a080
RBP: 00000000000000ff R08: 0000000000000001 R09: ffffffff8bc0a083
R10: fffffbfff1781410 R11: 0000000000000000 R12: 1ffff920018b4f4d
R13: ffffffff8bc0a084 R14: 0000000000000003 R15: fffffbfff1781410
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004e1a42 CR3: 000000005f129000 CR4: 0000000000350ef0
Call Trace:
 queued_write_lock include/asm-generic/qrwlock.h:95 [inline]
 do_raw_write_lock+0x1ce/0x280 kernel/locking/spinlock_debug.c:207
 exit_notify kernel/exit.c:667 [inline]
 do_exit+0xcaa/0x2ae0 kernel/exit.c:845
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x427/0x20f0 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x466019
Code: Unable to access opcode bytes at RIP 0x465fef.
RSP: 002b:00007fb72e4da218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000056c010 RCX: 0000000000466019
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056c010
RBP: 000000000056c008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c014
R13: 00007fff7716fcff R14: 00007fb72e4da300 R15: 0000000000022000
task:kworker/u4:7    state:R  running task     stack:25344 pid:12241 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5078
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5340
 irqentry_exit_cond_resched kernel/entry/common.c:385 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:377 [inline]
 irqentry_exit+0x7a/0xa0 kernel/entry/common.c:415
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629
RIP: 0010:lock_acquire+0x1d2/0x720 kernel/locking/lockdep.c:5410
Code: 48 c7 c7 80 ab 6b 89 48 83 c4 20 e8 18 0d a5 07 b8 ff ff ff ff 65 0f c1 05 bb 16 a9 7e 83 f8 01 0f 85 da 03 00 00 ff 34 24 9d <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7
RSP: 0018:ffffc90003677aa8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff920006cef57 RCX: 0000000000000001
RDX: 1ffff1100b4e7130 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fa7e7a7
R10: fffffbfff1f4fcf4 R11: 0000000000000000 R12: 0000000000000002
R13: ffffffff8bf73ee0 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:259 [inline]
 rcu_read_lock include/linux/rcupdate.h:648 [inline]
 batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline]
 batadv_iv_ogm_schedule_buff+0x5d0/0x1410 net/batman-adv/bat_iv_ogm.c:825
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:869 [inline]
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:862 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x675/0x920 net/batman-adv/bat_iv_ogm.c:1723
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
rcu: rcu_preempt kthread starved for 10502 jiffies! g56193 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:28888 pid:   13 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5078
 schedule+0xcf/0x270 kernel/sched/core.c:5157
 schedule_timeout+0x148/0x250 kernel/time/timer.c:1878
 rcu_gp_fqs_loop kernel/rcu/tree.c:1940 [inline]
 rcu_gp_kthread+0xbbe/0x1d70 kernel/rcu/tree.c:2113
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296