INFO: task syz.3.1485:10809 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1485      state:D stack:25560 pid:10809 tgid:10808 ppid:9584   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 nfsd_nl_listener_set_doit+0x137/0x1690
 genl_family_rcv_msg_doit+0x215/0x300
 genl_rcv_msg+0x60e/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffadf78ebe9
RSP: 002b:00007ffae050e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffadf9b5fa0 RCX: 00007ffadf78ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000009
RBP: 00007ffadf811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffadf9b6038 R14: 00007ffadf9b5fa0 R15: 00007ffddf820a48
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: bat_events batadv_mcast_mla_update
RIP: 0010:debug_check_no_obj_freed+0x205/0x470
Code: 00 ff c3 48 8b 44 24 18 49 89 c7 48 85 c0 0f 84 45 02 00 00 4d 89 fe 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 00 <74> 08 4c 89 ff e8 c1 d7 52 fd 49 8b 07 48 89 44 24 18 4d 8d 67 18
RSP: 0018:ffffc900000f7770 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000000002 RCX: dffffc0000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900000f7660
RBP: ffff888120ae1980 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200001eecc R12: ffff8881237b0130
R13: ffff888120ae1da0 R14: 1ffff11021b43d50 R15: ffff88810da1ea80
FS:  0000000000000000(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e411ff8 CR3: 000000002828c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 kfree+0x112/0x440
 batadv_mcast_mla_update+0x3293/0x3640
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
