netdevsim netdevsim1 eth2: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 eth3: set [1, 0] type 2 family 0 port 6081 - 0 ================================================================== BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:611 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x159/0x1420 kernel/locking/mutex.c:794 Read of size 8 at addr ffff88801dff5ea8 by task kworker/u8:6/164 CPU: 0 UID: 0 PID: 164 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: udp_tunnel_nic udp_tunnel_nic_device_sync_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __mutex_lock_common kernel/locking/mutex.c:611 [inline] __mutex_lock+0x159/0x1420 kernel/locking/mutex.c:794 udp_tunnel_nic_device_sync_work+0x39/0xa10 net/ipv4/udp_tunnel_nic.c:737 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6091: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5292 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5304 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+0x4c3/0x17d0 net/ipv4/udp_tunnel_nic.c:931 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2285 [inline] call_netdevice_notifiers net/core/dev.c:2299 [inline] register_netdevice+0x173a/0x1cf0 net/core/dev.c:11494 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1015 [inline] nsim_create+0xb92/0x1100 drivers/net/netdevsim/netdev.c:1097 __nsim_dev_port_add+0x72a/0xb50 drivers/net/netdevsim/dev.c:1493 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1549 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1601 [inline] nsim_dev_reload_up+0x45f/0x7c0 drivers/net/netdevsim/dev.c:1058 devlink_reload+0x4f8/0x8c0 net/devlink/dev.c:475 devlink_nl_reload_doit+0xaaa/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:786 [inline] __sock_sendmsg net/socket.c:801 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2650 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2704 __sys_sendmsg net/socket.c:2736 [inline] __do_sys_sendmsg net/socket.c:2741 [inline] __se_sys_sendmsg net/socket.c:2739 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6121: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/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:6242 [inline] kfree+0x1c5/0x640 mm/slub.c:6557 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+0x11ed/0x17d0 net/ipv4/udp_tunnel_nic.c:942 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2285 [inline] call_netdevice_notifiers net/core/dev.c:2299 [inline] unregister_netdevice_many_notify+0x186a/0x2370 net/core/dev.c:12446 unregister_netdevice_many net/core/dev.c:12509 [inline] unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12323 unregister_netdevice include/linux/netdevice.h:3418 [inline] nsim_destroy+0x21f/0x730 drivers/net/netdevsim/netdev.c:1134 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1528 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1540 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1764 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:1038 devlink_reload+0x1eb/0x8c0 net/devlink/dev.c:462 devlink_nl_reload_doit+0xaaa/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:786 [inline] __sock_sendmsg net/socket.c:801 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2650 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2704 __sys_sendmsg net/socket.c:2736 [inline] __do_sys_sendmsg net/socket.c:2741 [inline] __se_sys_sendmsg net/socket.c:2739 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 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:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2226 __queue_work+0xbad/0xfc0 kernel/workqueue.c:2385 queue_work_on+0x106/0x1d0 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_add_port+0xb71/0xd60 net/ipv4/udp_tunnel_nic.c:523 udp_tunnel_nic_add_port include/net/udp_tunnel.h:402 [inline] udp_tunnel_push_rx_port+0x186/0x210 net/ipv4/udp_tunnel_core.c:112 geneve_offload_rx_ports+0xc7/0x150 drivers/net/geneve.c:1657 geneve_netdevice_event+0x6a/0x80 drivers/net/geneve.c:-1 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2285 [inline] call_netdevice_notifiers+0x90/0xd0 net/core/dev.c:2299 udp_tunnel_get_rx_info include/net/udp_tunnel.h:469 [inline] udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline] udp_tunnel_nic_netdevice_event+0xdef/0x17d0 net/ipv4/udp_tunnel_nic.c:931 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2285 [inline] call_netdevice_notifiers net/core/dev.c:2299 [inline] register_netdevice+0x173a/0x1cf0 net/core/dev.c:11494 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1015 [inline] nsim_create+0xb92/0x1100 drivers/net/netdevsim/netdev.c:1097 __nsim_dev_port_add+0x72a/0xb50 drivers/net/netdevsim/dev.c:1493 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1549 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1601 [inline] nsim_dev_reload_up+0x45f/0x7c0 drivers/net/netdevsim/dev.c:1058 devlink_reload+0x4f8/0x8c0 net/devlink/dev.c:475 devlink_nl_reload_doit+0xaaa/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:786 [inline] __sock_sendmsg net/socket.c:801 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2650 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2704 __sys_sendmsg net/socket.c:2736 [inline] __do_sys_sendmsg net/socket.c:2741 [inline] __se_sys_sendmsg net/socket.c:2739 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/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+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2226 __queue_work+0xccf/0xfc0 kernel/workqueue.c:2381 queue_work_on+0x106/0x1d0 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_add_port+0xb71/0xd60 net/ipv4/udp_tunnel_nic.c:523 udp_tunnel_nic_add_port include/net/udp_tunnel.h:402 [inline] udp_tunnel_push_rx_port+0x186/0x210 net/ipv4/udp_tunnel_core.c:112 geneve_offload_rx_ports+0xc7/0x150 drivers/net/geneve.c:1657 geneve_netdevice_event+0x6a/0x80 drivers/net/geneve.c:-1 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2285 [inline] call_netdevice_notifiers+0x90/0xd0 net/core/dev.c:2299 udp_tunnel_get_rx_info include/net/udp_tunnel.h:469 [inline] udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline] udp_tunnel_nic_netdevice_event+0xdef/0x17d0 net/ipv4/udp_tunnel_nic.c:931 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2285 [inline] call_netdevice_notifiers net/core/dev.c:2299 [inline] register_netdevice+0x173a/0x1cf0 net/core/dev.c:11494 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1015 [inline] nsim_create+0xb92/0x1100 drivers/net/netdevsim/netdev.c:1097 __nsim_dev_port_add+0x72a/0xb50 drivers/net/netdevsim/dev.c:1493 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1549 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1601 [inline] nsim_dev_reload_up+0x45f/0x7c0 drivers/net/netdevsim/dev.c:1058 devlink_reload+0x4f8/0x8c0 net/devlink/dev.c:475 devlink_nl_reload_doit+0xaaa/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:786 [inline] __sock_sendmsg net/socket.c:801 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2650 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2704 __sys_sendmsg net/socket.c:2736 [inline] __do_sys_sendmsg net/socket.c:2741 [inline] __se_sys_sendmsg net/socket.c:2739 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801dff5e00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 168 bytes inside of freed 256-byte region [ffff88801dff5e00, ffff88801dff5f00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1dff4 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 ffff88813fe25b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe25b40 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 5840, tgid 5840 (syz-executor), ts 89992138975, free_ts 89965547653 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x339/0x3d0 mm/slub.c:7247 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x321/0x720 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:5291 [inline] __kmalloc_noprof+0x474/0x760 mm/slub.c:5304 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] fib_create_info+0x1723/0x31f0 net/ipv4/fib_semantics.c:1400 fib_table_insert+0xc8/0x1b50 net/ipv4/fib_trie.c:1212 fib_magic+0x434/0x510 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+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2285 [inline] call_netdevice_notifiers net/core/dev.c:2299 [inline] __dev_notify_flags+0x1a9/0x310 net/core/dev.c:9835 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9864 do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3180 page last free pid 5932 tgid 5932 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697 alloc_skb include/linux/skbuff.h:1383 [inline] mld_newpack+0x14c/0xc90 net/ipv6/mcast.c:1775 add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1886 add_grec+0x1452/0x1740 net/ipv6/mcast.c:2025 mld_send_cr net/ipv6/mcast.c:2148 [inline] mld_ifc_work+0x6e6/0xe70 net/ipv6/mcast.c:2693 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88801dff5d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801dff5e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801dff5e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801dff5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801dff5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================