==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:625 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0x1580/0x1b10 kernel/locking/mutex.c:820
Read of size 8 at addr ffff888035d8bca8 by task kworker/u8:5/111

CPU: 1 UID: 0 PID: 111 Comm: kworker/u8:5 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: udp_tunnel_nic udp_tunnel_nic_device_sync_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595
 __mutex_lock_common kernel/locking/mutex.c:625 [inline]
 __mutex_lock+0x1580/0x1b10 kernel/locking/mutex.c:820
 udp_tunnel_nic_device_sync_work+0x3b/0xa50 net/ipv4/udp_tunnel_nic.c:737
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 15891:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5295 [inline]
 __kmalloc_noprof+0x301/0x850 mm/slub.c:5307
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [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+0x12c6/0x1dd0 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x18fe/0x24b0 net/core/dev.c:11458
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1069 [inline]
 nsim_create+0xc8d/0x1420 drivers/net/netdevsim/netdev.c:1151
 __nsim_dev_port_add+0x3ba/0x8f0 drivers/net/netdevsim/dev.c:1509
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1570 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1622 [inline]
 nsim_dev_reload_up+0x586/0x830 drivers/net/netdevsim/dev.c:1058
 devlink_reload+0x2f2/0x7a0 net/devlink/dev.c:475
 devlink_nl_reload_doit+0xd1a/0x11c0 net/devlink/dev.c:585
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
 __sys_sendmsg+0x170/0x220 net/socket.c:2784
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 15892:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kfree+0x223/0x6c0 mm/slub.c:6561
 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+0xb7d/0x1dd0 net/ipv4/udp_tunnel_nic.c:942
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 unregister_netdevice_many_notify+0x118f/0x24f0 net/core/dev.c:12418
 unregister_netdevice_many net/core/dev.c:12481 [inline]
 unregister_netdevice_queue net/core/dev.c:12291 [inline]
 unregister_netdevice_queue+0x30b/0x3c0 net/core/dev.c:12281
 unregister_netdevice include/linux/netdevice.h:3444 [inline]
 nsim_destroy+0x1ce/0x8e0 drivers/net/netdevsim/netdev.c:1192
 __nsim_dev_port_del+0x194/0x2b0 drivers/net/netdevsim/dev.c:1547
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1561 [inline]
 nsim_dev_reload_destroy+0x10a/0x4a0 drivers/net/netdevsim/dev.c:1785
 nsim_dev_reload_down+0x66/0xd0 drivers/net/netdevsim/dev.c:1038
 devlink_reload+0x1ae/0x7a0 net/devlink/dev.c:462
 devlink_nl_reload_doit+0xd1a/0x11c0 net/devlink/dev.c:585
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
 __sys_sendmsg+0x170/0x220 net/socket.c:2784
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
 insert_work+0x36/0x230 kernel/workqueue.c:2226
 __queue_work+0x3fd/0x1130 kernel/workqueue.c:2385
 queue_work_on+0x180/0x1e0 kernel/workqueue.c:2432
 queue_work include/linux/workqueue.h:696 [inline]
 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:307 [inline]
 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:302 [inline]
 __udp_tunnel_nic_add_port+0x6cd/0xd60 net/ipv4/udp_tunnel_nic.c:523
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:402 [inline]
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:397 [inline]
 udp_tunnel_push_rx_port+0x1af/0x230 net/ipv4/udp_tunnel_core.c:112
 geneve_offload_rx_ports+0xbc/0x190 drivers/net/geneve.c:1657
 geneve_netdevice_event+0x77/0xb0 drivers/net/geneve.c:2421
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers+0x7c/0xb0 net/core/dev.c:2301
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:469 [inline]
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:463 [inline]
 udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline]
 udp_tunnel_nic_netdevice_event+0x1240/0x1dd0 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x18fe/0x24b0 net/core/dev.c:11458
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1069 [inline]
 nsim_create+0xc8d/0x1420 drivers/net/netdevsim/netdev.c:1151
 __nsim_dev_port_add+0x3ba/0x8f0 drivers/net/netdevsim/dev.c:1509
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1570 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1622 [inline]
 nsim_dev_reload_up+0x586/0x830 drivers/net/netdevsim/dev.c:1058
 devlink_reload+0x2f2/0x7a0 net/devlink/dev.c:475
 devlink_nl_reload_doit+0xd1a/0x11c0 net/devlink/dev.c:585
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
 __sys_sendmsg+0x170/0x220 net/socket.c:2784
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Second to last potentially related work creation:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
 insert_work+0x36/0x230 kernel/workqueue.c:2226
 __queue_work+0x9a2/0x1130 kernel/workqueue.c:2381
 queue_work_on+0x180/0x1e0 kernel/workqueue.c:2432
 queue_work include/linux/workqueue.h:696 [inline]
 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:307 [inline]
 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:302 [inline]
 __udp_tunnel_nic_add_port+0x6cd/0xd60 net/ipv4/udp_tunnel_nic.c:523
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:402 [inline]
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:397 [inline]
 udp_tunnel_push_rx_port+0x1af/0x230 net/ipv4/udp_tunnel_core.c:112
 geneve_offload_rx_ports+0xbc/0x190 drivers/net/geneve.c:1657
 geneve_netdevice_event+0x77/0xb0 drivers/net/geneve.c:2421
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers+0x7c/0xb0 net/core/dev.c:2301
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:469 [inline]
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:463 [inline]
 udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline]
 udp_tunnel_nic_netdevice_event+0x1240/0x1dd0 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x18fe/0x24b0 net/core/dev.c:11458
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1069 [inline]
 nsim_create+0xc8d/0x1420 drivers/net/netdevsim/netdev.c:1151
 __nsim_dev_port_add+0x3ba/0x8f0 drivers/net/netdevsim/dev.c:1509
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1570 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1622 [inline]
 nsim_dev_reload_up+0x586/0x830 drivers/net/netdevsim/dev.c:1058
 devlink_reload+0x2f2/0x7a0 net/devlink/dev.c:475
 devlink_nl_reload_doit+0xd1a/0x11c0 net/devlink/dev.c:585
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
 __sys_sendmsg+0x170/0x220 net/socket.c:2784
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888035d8bc00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 168 bytes inside of
 freed 256-byte region [ffff888035d8bc00, ffff888035d8bd00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35d8a
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 ffff88813fe34b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe34b40 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffffffffffff81 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 1, tgid 1 (swapper/0), ts 19511091358, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab mm/slub.c:3467 [inline]
 new_slab+0xa6/0x6c0 mm/slub.c:3525
 refill_objects+0x277/0x420 mm/slub.c:7251
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __do_kmalloc_node mm/slub.c:5294 [inline]
 __kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5403
 __do_krealloc mm/slub.c:6706 [inline]
 krealloc_node_align_noprof+0x1f9/0x3e0 mm/slub.c:6765
 add_sysfs_param+0xdb/0x970 kernel/params.c:648
 kernel_add_sysfs_param kernel/params.c:797 [inline]
 param_sysfs_builtin kernel/params.c:836 [inline]
 param_sysfs_builtin_init+0x313/0x3f0 kernel/params.c:972
 do_one_initcall+0x121/0x750 init/main.c:1392
 do_initcall_level init/main.c:1454 [inline]
 do_initcalls init/main.c:1470 [inline]
 do_basic_setup init/main.c:1490 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703
 kernel_init+0x1f/0x1e0 init/main.c:1593
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888035d8bb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888035d8bc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888035d8bc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888035d8bd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888035d8bd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================