syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=66fc/1/0x4000000000000000 softirq=121040/121040 fqs=1
	(detected by 1, t=10502 jiffies, g=148917, q=164 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11 Comm: kworker/u4:1 Not tainted 6.1.0-syzkaller-04375-g558016722e9d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: bat_events batadv_dat_purge
RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:760 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x60/0x140 kernel/rcu/tree.c:752
Code: 03 00 83 f8 07 89 c5 0f 87 e9 00 00 00 48 8d 3c ed 00 f9 12 8c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 a4 00 00 00 48 03 1c ed 00 f9 12 8c 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90000007c38 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 000000000003c440 RCX: ffffffff8163f019
RDX: 1ffffffff1825f20 RSI: 0000000000010004 RDI: ffffffff8c12f900
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8e72dc17
R10: fffffbfff1ce5b82 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff8a4eb960 R14: 0000000000000000 R15: ffff88807a709340
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555573a5708 CR3: 0000000021d55000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline]
 rcu_read_lock_held_common kernel/rcu/update.c:102 [inline]
 rcu_read_lock_sched_held+0x29/0x70 kernel/rcu/update.c:123
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x5cf/0x810 kernel/locking/lockdep.c:5679
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x1a/0x70 kernel/locking/spinlock.c:194
 debug_object_deactivate lib/debugobjects.c:761 [inline]
 debug_object_deactivate+0x268/0x300 lib/debugobjects.c:727
 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
 debug_deactivate kernel/time/hrtimer.c:481 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1653 [inline]
 __hrtimer_run_queues+0x422/0xfb0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x320/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
 __sysvec_apic_timer_interrupt+0x180/0x640 arch/x86/kernel/apic/apic.c:1113
 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1107
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:__local_bh_enable_ip+0xac/0x130 kernel/softirq.c:403
Code: 1d 21 d4 b6 7e 65 8b 05 1a d4 b6 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 51 e7 09 00 e8 1c fc 3a 00 fb 65 8b 05 fc d3 b6 7e <85> c0 74 58 5b 5d c3 65 8b 05 22 ae b5 7e 85 c0 75 a2 0f 0b eb 9e
RSP: 0018:ffffc90000107c88 EFLAGS: 00000202
RAX: 0000000080000000 RBX: 00000000fffffe00 RCX: 1ffffffff227280e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff8992080f R08: 0000000000000001 R09: ffffffff91335bbf
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801e749478
R13: dffffc0000000000 R14: ffffffff8991fd30 R15: 000000000000028f
 spin_unlock_bh include/linux/spinlock.h:395 [inline]
 __batadv_dat_purge.part.0+0x29f/0x3b0 net/batman-adv/distributed-arp-table.c:187
 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:168 [inline]
 batadv_dat_purge+0x4b/0x70 net/batman-adv/distributed-arp-table.c:206
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: rcu_preempt kthread starved for 9879 jiffies! g148917 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:28656 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6555
 schedule+0xde/0x1b0 kernel/sched/core.c:6631
 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1656
 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1855
 kthread+0x2e8/0x3a0 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:
CPU: 1 PID: 14162 Comm: syz-executor.3 Not tainted 6.1.0-syzkaller-04375-g558016722e9d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:236
Code: 01 00 00 49 89 f8 65 48 8b 14 25 00 ac 03 00 a9 00 01 ff 00 74 0e 85 f6 74 59 8b 82 6c 15 00 00 85 c0 74 4f 8b 82 48 15 00 00 <83> f8 03 75 44 48 8b 82 50 15 00 00 8b 92 4c 15 00 00 48 8b 38 48
RSP: 0018:ffffc9000389f138 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 1ffff92000713e2c RCX: ffffffff81766da5
RDX: ffff888020021d40 RSI: 0000000000000000 RDI: 0000000000000005
RBP: ffffc9000389f248 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000002
FS:  00007f41c5655700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f70489caff8 CR3: 0000000022ea0000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:413 [inline]
 smp_call_function_single+0x215/0x680 kernel/smp.c:776
 rcu_barrier+0x296/0x6d0 kernel/rcu/tree.c:4049
 br_multicast_dev_del+0x1e0/0x240 net/bridge/br_multicast.c:4200
 br_dev_uninit+0x1d/0x70 net/bridge/br_device.c:163
 register_netdevice+0xb26/0x1640 net/core/dev.c:10101
 br_dev_newlink+0x27/0x110 net/bridge/br_netlink.c:1517
 rtnl_newlink_create net/core/rtnetlink.c:3407 [inline]
 __rtnl_newlink+0x10c2/0x1840 net/core/rtnetlink.c:3624
 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3637
 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2564
 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356
 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xd3/0x120 net/socket.c:734
 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f41c488c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f41c5655168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f41c49ac050 RCX: 00007f41c488c0c9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000008
RBP: 00007f41c48e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe308947ff R14: 00007f41c5655300 R15: 0000000000022000
 </TASK>