==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock+0x147/0x1350
Read of size 8 at addr ffff88801fe7e4b0 by task kworker/u8:5/15754

CPU: 1 UID: 0 PID: 15754 Comm: kworker/u8:5 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: udp_tunnel_nic udp_tunnel_nic_device_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __mutex_lock+0x147/0x1350
 udp_tunnel_nic_device_sync_work+0x39/0xa10
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 23075:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x411/0x800
 udp_tunnel_nic_netdevice_event+0x4c3/0x17d0
 notifier_call_chain+0x19d/0x3a0
 register_netdevice+0x15bd/0x1a70
 nsim_create+0xb3f/0x1050
 __nsim_dev_port_add+0x6a6/0xaf0
 nsim_dev_port_add_all+0x37/0xf0
 nsim_dev_reload_up+0x451/0x780
 devlink_reload+0x4ec/0x8d0
 devlink_nl_reload_doit+0xa8d/0xc60
 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+0x505/0x820
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 23076:
 kasan_save_track+0x3e/0x80
 __kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c0/0x660
 udp_tunnel_nic_netdevice_event+0x11ed/0x17d0
 notifier_call_chain+0x19d/0x3a0
 unregister_netdevice_many_notify+0x1830/0x2310
 unregister_netdevice_queue+0x317/0x350
 nsim_destroy+0x1e5/0x680
 __nsim_dev_port_del+0x14d/0x1b0
 nsim_dev_reload_destroy+0x288/0x490
 nsim_dev_reload_down+0x8a/0xc0
 devlink_reload+0x1b6/0x8d0
 devlink_nl_reload_doit+0xa8d/0xc60
 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+0x505/0x820
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 insert_work+0x3d/0x330
 __queue_work+0xbae/0xf90
 queue_work_on+0x181/0x270
 __udp_tunnel_nic_add_port+0xb71/0xd60
 udp_tunnel_push_rx_port+0x180/0x200
 geneve_offload_rx_ports+0xc7/0x150
 geneve_netdevice_event+0x6a/0x80
 notifier_call_chain+0x19d/0x3a0
 call_netdevice_notifiers+0x88/0xc0
 udp_tunnel_nic_netdevice_event+0xdef/0x17d0
 notifier_call_chain+0x19d/0x3a0
 register_netdevice+0x15bd/0x1a70
 nsim_create+0xb3f/0x1050
 __nsim_dev_port_add+0x6a6/0xaf0
 nsim_dev_port_add_all+0x37/0xf0
 nsim_dev_reload_up+0x451/0x780
 devlink_reload+0x4ec/0x8d0
 devlink_nl_reload_doit+0xa8d/0xc60
 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+0x505/0x820
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 insert_work+0x3d/0x330
 __queue_work+0xcd0/0xf90
 queue_work_on+0x181/0x270
 __udp_tunnel_nic_add_port+0xb71/0xd60
 udp_tunnel_push_rx_port+0x180/0x200
 vxlan_offload_rx_ports+0x129/0x1f0
 vxlan_netdevice_event+0x111/0x470
 notifier_call_chain+0x19d/0x3a0
 call_netdevice_notifiers+0x88/0xc0
 udp_tunnel_nic_netdevice_event+0xdef/0x17d0
 notifier_call_chain+0x19d/0x3a0
 register_netdevice+0x15bd/0x1a70
 nsim_create+0xb3f/0x1050
 __nsim_dev_port_add+0x6a6/0xaf0
 nsim_dev_port_add_all+0x37/0xf0
 nsim_dev_reload_up+0x451/0x780
 devlink_reload+0x4ec/0x8d0
 devlink_nl_reload_doit+0xa8d/0xc60
 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+0x505/0x820
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801fe7e400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 176 bytes inside of
 freed 256-byte region [ffff88801fe7e400, ffff88801fe7e500)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88801fe7fe00 pfn:0x1fe7e
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888100041b40 ffffea0004429780 dead000000000006
raw: ffff88801fe7fe00 000000008010000b 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff888100041b40 ffffea0004429780 dead000000000006
head: ffff88801fe7fe00 000000008010000b 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea00007f9f81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5842, tgid 5842 (syz-executor), ts 55195017322, free_ts 0
 post_alloc_hook+0x234/0x290
 get_page_from_freelist+0x2365/0x2440
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x86/0x3b0
 ___slab_alloc+0xf2b/0x1960
 __slab_alloc+0x65/0x100
 __kmalloc_noprof+0x471/0x800
 fib_create_info+0x171d/0x31f0
 fib_table_insert+0xc6/0x1b50
 fib_magic+0x2c4/0x390
 fib_add_ifaddr+0x144/0x5f0
 fib_netdev_event+0x382/0x490
 notifier_call_chain+0x19d/0x3a0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88801fe7e380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801fe7e400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801fe7e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88801fe7e500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801fe7e580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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