syzbot

netdevsim netdevsim0 eth0: set [1, 0] type 2 family 0 port 6081 - 0
==================================================================
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+0xc70/0x1060 kernel/locking/mutex.c:760
Read of size 8 at addr ffff88807d8036b0 by task kworker/u8:9/14544

CPU: 0 UID: 0 PID: 14544 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: udp_tunnel_nic udp_tunnel_nic_device_sync_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 __mutex_lock_common kernel/locking/mutex.c:577 [inline]
 __mutex_lock+0xc70/0x1060 kernel/locking/mutex.c:760
 udp_tunnel_nic_device_sync_work+0x3b/0xa10 net/ipv4/udp_tunnel_nic.c:737
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 27090:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_noprof+0x223/0x510 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [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+0x1383/0x1fa0 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x182e/0x2270 net/core/dev.c:11244
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1034 [inline]
 nsim_create+0xdd5/0x1260 drivers/net/netdevsim/netdev.c:1105
 __nsim_dev_port_add+0x435/0x7d0 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1494 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x5b8/0x860 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x325/0x7c0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 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+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 27090:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4879
 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+0xd2a/0x1fa0 net/ipv4/udp_tunnel_nic.c:942
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 unregister_netdevice_many_notify+0xf76/0x24c0 net/core/dev.c:12166
 unregister_netdevice_many net/core/dev.c:12229 [inline]
 unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:12073
 unregister_netdevice include/linux/netdevice.h:3385 [inline]
 nsim_destroy+0x198/0x800 drivers/net/netdevsim/netdev.c:1140
 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1473
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1485 [inline]
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1501 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x62e/0x860 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x325/0x7c0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 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+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548
 insert_work+0x36/0x230 kernel/workqueue.c:2184
 __queue_work+0x3f8/0x1160 kernel/workqueue.c:2343
 queue_work_on+0x1a4/0x1f0 kernel/workqueue.c:2390
 queue_work include/linux/workqueue.h:669 [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+0x6f8/0xde0 net/ipv4/udp_tunnel_nic.c:523
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:371 [inline]
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:366 [inline]
 udp_tunnel_push_rx_port+0x1ac/0x230 net/ipv4/udp_tunnel_core.c:111
 geneve_offload_rx_ports+0xbf/0x1c0 drivers/net/geneve.c:1188
 geneve_netdevice_event+0x77/0xb0 drivers/net/geneve.c:1931
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers+0x7c/0xb0 net/core/dev.c:2281
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:438 [inline]
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:432 [inline]
 udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline]
 udp_tunnel_nic_netdevice_event+0x12fd/0x1fa0 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x182e/0x2270 net/core/dev.c:11244
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1034 [inline]
 nsim_create+0xdd5/0x1260 drivers/net/netdevsim/netdev.c:1105
 __nsim_dev_port_add+0x435/0x7d0 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1494 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x5b8/0x860 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x325/0x7c0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 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+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Second to last potentially related work creation:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548
 insert_work+0x36/0x230 kernel/workqueue.c:2184
 __queue_work+0x97e/0x1160 kernel/workqueue.c:2339
 queue_work_on+0x1a4/0x1f0 kernel/workqueue.c:2390
 queue_work include/linux/workqueue.h:669 [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+0x6f8/0xde0 net/ipv4/udp_tunnel_nic.c:523
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:371 [inline]
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:366 [inline]
 udp_tunnel_push_rx_port+0x1ac/0x230 net/ipv4/udp_tunnel_core.c:111
 geneve_offload_rx_ports+0xbf/0x1c0 drivers/net/geneve.c:1188
 geneve_netdevice_event+0x77/0xb0 drivers/net/geneve.c:1931
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers+0x7c/0xb0 net/core/dev.c:2281
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:438 [inline]
 udp_tunnel_get_rx_info include/net/udp_tunnel.h:432 [inline]
 udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:855 [inline]
 udp_tunnel_nic_netdevice_event+0x12fd/0x1fa0 net/ipv4/udp_tunnel_nic.c:931
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x182e/0x2270 net/core/dev.c:11244
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1034 [inline]
 nsim_create+0xdd5/0x1260 drivers/net/netdevsim/netdev.c:1105
 __nsim_dev_port_add+0x435/0x7d0 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1494 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x5b8/0x860 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x325/0x7c0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 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+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807d803600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 176 bytes inside of
 freed 256-byte region [ffff88807d803600, ffff88807d803700)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d802
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 ffff88801b841b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b841b40 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea0001f60081 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 5843, tgid 5843 (syz-executor), ts 73246144734, free_ts 73242785423
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab mm/slub.c:2655 [inline]
 new_slab+0x247/0x330 mm/slub.c:2709
 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 __do_kmalloc_node mm/slub.c:4364 [inline]
 __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 new_dir fs/proc/proc_sysctl.c:966 [inline]
 get_subdir fs/proc/proc_sysctl.c:1010 [inline]
 sysctl_mkdir_p fs/proc/proc_sysctl.c:1320 [inline]
 __register_sysctl_table+0xea2/0x1900 fs/proc/proc_sysctl.c:1395
 mpls_dev_sysctl_register+0x185/0x2a0 net/mpls/af_mpls.c:1405
 mpls_add_dev net/mpls/af_mpls.c:1460 [inline]
 mpls_dev_notify+0x4ab/0xa20 net/mpls/af_mpls.c:1600
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x182e/0x2270 net/core/dev.c:11244
 veth_newlink+0x446/0xa00 drivers/net/veth.c:1884
 rtnl_newlink_create net/core/rtnetlink.c:3825 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3942 [inline]
 rtnl_newlink+0xc42/0x2000 net/core/rtnetlink.c:4057
page last free pid 5843 tgid 5843 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0x799/0x1530 kernel/rcu/tree.c:2861
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Memory state around the buggy address:
 ffff88807d803580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807d803600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807d803680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88807d803700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807d803780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================