==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:577 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0x147/0x1350 kernel/locking/mutex.c:760
Read of size 8 at addr ffff888032f8b0b0 by task kworker/u8:1/13

CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: udp_tunnel_nic udp_tunnel_nic_device_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 __mutex_lock_common kernel/locking/mutex.c:577 [inline]
 __mutex_lock+0x147/0x1350 kernel/locking/mutex.c:760
 udp_tunnel_nic_device_sync_work+0x39/0xa50 net/ipv4/udp_tunnel_nic.c:737
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 7249:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5604 [inline]
 __kmalloc_noprof+0x411/0x7f0 mm/slub.c:5616
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 udp_tunnel_nic_alloc net/ipv4/udp_tunnel_nic.c:756 [inline]
 udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:833 [inline]
 udp_tunnel_nic_netdevice_event+0x4c3/0x1820 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x1608/0x1ae0 net/core/dev.c:11332
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1052 [inline]
 nsim_create+0xae8/0xf10 drivers/net/netdevsim/netdev.c:1134
 __nsim_dev_port_add+0x6b6/0xb10 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1494
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x451/0x780 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x4ec/0x8d0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xb35/0xd50 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 7253:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2515 [inline]
 slab_free mm/slub.c:6574 [inline]
 kfree+0x19a/0x6d0 mm/slub.c:6781
 udp_tunnel_nic_free net/ipv4/udp_tunnel_nic.c:785 [inline]
 udp_tunnel_nic_unregister net/ipv4/udp_tunnel_nic.c:910 [inline]
 udp_tunnel_nic_netdevice_event+0x11b8/0x1820 net/ipv4/udp_tunnel_nic.c:942
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 unregister_netdevice_many_notify+0x14d7/0x1ff0 net/core/dev.c:12268
 unregister_netdevice_many net/core/dev.c:12331 [inline]
 unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12175
 unregister_netdevice include/linux/netdevice.h:3392 [inline]
 nsim_destroy+0x1dd/0x670 drivers/net/netdevsim/netdev.c:1171
 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1473
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1485 [inline]
 nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1707
 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:983
 devlink_reload+0x1b6/0x8d0 net/devlink/dev.c:461
 devlink_nl_reload_doit+0xb35/0xd50 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559
 insert_work+0x3d/0x330 kernel/workqueue.c:2186
 __queue_work+0xbaf/0xfb0 kernel/workqueue.c:2345
 queue_work_on+0x181/0x270 kernel/workqueue.c:2392
 queue_work include/linux/workqueue.h:669 [inline]
 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:307 [inline]
 __udp_tunnel_nic_add_port+0xb71/0xd60 net/ipv4/udp_tunnel_nic.c:523
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:371 [inline]
 udp_tunnel_push_rx_port+0x180/0x200 net/ipv4/udp_tunnel_core.c:112
 geneve_offload_rx_ports+0xd7/0x160 drivers/net/geneve.c:1190
 geneve_netdevice_event+0x6a/0x80 drivers/net/geneve.c:-1
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers+0x88/0xc0 net/core/dev.c:2281
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:438 [inline]
 udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline]
 udp_tunnel_nic_netdevice_event+0xe0c/0x1820 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x1608/0x1ae0 net/core/dev.c:11332
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1052 [inline]
 nsim_create+0xae8/0xf10 drivers/net/netdevsim/netdev.c:1134
 __nsim_dev_port_add+0x6b6/0xb10 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1494
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x451/0x780 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x4ec/0x8d0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xb35/0xd50 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559
 insert_work+0x3d/0x330 kernel/workqueue.c:2186
 __queue_work+0xcd2/0xfb0 kernel/workqueue.c:2341
 queue_work_on+0x181/0x270 kernel/workqueue.c:2392
 queue_work include/linux/workqueue.h:669 [inline]
 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:307 [inline]
 __udp_tunnel_nic_add_port+0xb71/0xd60 net/ipv4/udp_tunnel_nic.c:523
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:371 [inline]
 udp_tunnel_push_rx_port+0x180/0x200 net/ipv4/udp_tunnel_core.c:112
 geneve_offload_rx_ports+0xd7/0x160 drivers/net/geneve.c:1190
 geneve_netdevice_event+0x6a/0x80 drivers/net/geneve.c:-1
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers+0x88/0xc0 net/core/dev.c:2281
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:438 [inline]
 udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline]
 udp_tunnel_nic_netdevice_event+0xe0c/0x1820 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x1608/0x1ae0 net/core/dev.c:11332
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1052 [inline]
 nsim_create+0xae8/0xf10 drivers/net/netdevsim/netdev.c:1134
 __nsim_dev_port_add+0x6b6/0xb10 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1494
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x451/0x780 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x4ec/0x8d0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xb35/0xd50 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888032f8b000
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 176 bytes inside of
 freed 256-byte region [ffff888032f8b000, ffff888032f8b100)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32f8a
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 ffff88813fe26b40 ffffea0000cc1100 dead000000000004
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe26b40 ffffea0000cc1100 dead000000000004
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea0000cbe281 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 5822, tgid 5822 (syz-executor), ts 74108175349, free_ts 73839157408
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3031 [inline]
 allocate_slab+0x96/0x3a0 mm/slub.c:3204
 new_slab mm/slub.c:3258 [inline]
 ___slab_alloc+0xe94/0x18a0 mm/slub.c:4628
 __slab_alloc+0x65/0x100 mm/slub.c:4747
 __slab_alloc_node mm/slub.c:4823 [inline]
 slab_alloc_node mm/slub.c:5234 [inline]
 __do_kmalloc_node mm/slub.c:5603 [inline]
 __kmalloc_noprof+0x471/0x7f0 mm/slub.c:5616
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 fib_create_info+0x172d/0x3210 net/ipv4/fib_semantics.c:1402
 fib_table_insert+0xc6/0x1b50 net/ipv4/fib_trie.c:1212
 fib_magic+0x2c4/0x390 net/ipv4/fib_frontend.c:1134
 fib_add_ifaddr+0x3fb/0x5f0 net/ipv4/fib_frontend.c:1178
 fib_netdev_event+0x382/0x490 net/ipv4/fib_frontend.c:1516
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1
 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9705
page last free pid 5822 tgid 5822 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906
 __slab_free+0x2e7/0x390 mm/slub.c:5924
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4947 [inline]
 slab_alloc_node mm/slub.c:5246 [inline]
 __kmalloc_cache_noprof+0x36f/0x6f0 mm/slub.c:5720
 kmalloc_noprof include/linux/slab.h:957 [inline]
 netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:664 [inline]
 netdevice_event+0x3a1/0x8c0 drivers/infiniband/core/roce_gid_mgmt.c:823
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers+0x88/0xc0 net/core/dev.c:2281
 vlan_dev_inherit_address net/8021q/vlan_dev.c:256 [inline]
 vlan_dev_open+0x213/0x5e0 net/8021q/vlan_dev.c:271
 __dev_open+0x470/0x880 net/core/dev.c:1682
 __dev_change_flags+0x1ea/0x6d0 net/core/dev.c:9637
 netif_change_flags+0x88/0x1a0 net/core/dev.c:9700
 dev_change_flags+0x130/0x260 net/core/dev_api.c:68
 vlan_device_event+0x1bc2/0x1ef0 net/8021q/vlan.c:492
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85

Memory state around the buggy address:
 ffff888032f8af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888032f8b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888032f8b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888032f8b100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888032f8b180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================