================================================================== 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+0x154/0x1550 kernel/locking/mutex.c:821 Read of size 8 at addr ffff88807afadca8 by task kworker/u8:23/23497 CPU: 1 UID: 0 PID: 23497 Comm: kworker/u8:23 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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:625 [inline] __mutex_lock+0x154/0x1550 kernel/locking/mutex.c:821 udp_tunnel_nic_device_sync_work+0x39/0xa20 net/ipv4/udp_tunnel_nic.c:737 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478 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 7291: 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:5296 [inline] __kmalloc_noprof+0x358/0x750 mm/slub.c:5308 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+0x4e9/0x1850 net/ipv4/udp_tunnel_nic.c:931 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x18db/0x1f00 net/core/dev.c:11461 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1069 [inline] nsim_create+0xbd7/0x1140 drivers/net/netdevsim/netdev.c:1151 __nsim_dev_port_add+0x7f8/0xcd0 drivers/net/netdevsim/dev.c:1509 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1570 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1622 [inline] nsim_dev_reload_up+0x47d/0x780 drivers/net/netdevsim/dev.c:1058 devlink_reload+0x4b2/0x890 net/devlink/dev.c:475 devlink_nl_reload_doit+0x921/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2687 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2741 __sys_sendmsg net/socket.c:2773 [inline] __do_sys_sendmsg net/socket.c:2778 [inline] __se_sys_sendmsg net/socket.c:2776 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2776 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7291: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 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:6251 [inline] kfree+0x1c5/0x640 mm/slub.c:6566 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+0x1236/0x1850 net/ipv4/udp_tunnel_nic.c:942 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] unregister_netdevice_many_notify+0x182a/0x2370 net/core/dev.c:12421 unregister_netdevice_many net/core/dev.c:12484 [inline] unregister_netdevice_queue+0x2f5/0x340 net/core/dev.c:12294 unregister_netdevice include/linux/netdevice.h:3444 [inline] nsim_destroy+0x26d/0x800 drivers/net/netdevsim/netdev.c:1193 __nsim_dev_port_del+0x14e/0x200 drivers/net/netdevsim/dev.c:1547 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1561 [inline] nsim_dev_port_add_all+0xae/0xf0 drivers/net/netdevsim/dev.c:1577 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1622 [inline] nsim_dev_reload_up+0x47d/0x780 drivers/net/netdevsim/dev.c:1058 devlink_reload+0x4b2/0x890 net/devlink/dev.c:475 devlink_nl_reload_doit+0x921/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2687 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2741 __sys_sendmsg net/socket.c:2773 [inline] __do_sys_sendmsg net/socket.c:2778 [inline] __se_sys_sendmsg net/socket.c:2776 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2776 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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+0xb7c/0xff0 kernel/workqueue.c:2397 queue_work_on+0x106/0x1d0 kernel/workqueue.c:2444 queue_work include/linux/workqueue.h:698 [inline] udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:307 [inline] __udp_tunnel_nic_add_port+0xba9/0xd90 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+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers+0x90/0xd0 net/core/dev.c:2301 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+0xe33/0x1850 net/ipv4/udp_tunnel_nic.c:931 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x18db/0x1f00 net/core/dev.c:11461 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1069 [inline] nsim_create+0xbd7/0x1140 drivers/net/netdevsim/netdev.c:1151 __nsim_dev_port_add+0x7f8/0xcd0 drivers/net/netdevsim/dev.c:1509 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1570 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1622 [inline] nsim_dev_reload_up+0x47d/0x780 drivers/net/netdevsim/dev.c:1058 devlink_reload+0x4b2/0x890 net/devlink/dev.c:475 devlink_nl_reload_doit+0x921/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2687 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2741 __sys_sendmsg net/socket.c:2773 [inline] __do_sys_sendmsg net/socket.c:2778 [inline] __se_sys_sendmsg net/socket.c:2776 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2776 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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+0xcb6/0xff0 kernel/workqueue.c:2393 queue_work_on+0x106/0x1d0 kernel/workqueue.c:2444 queue_work include/linux/workqueue.h:698 [inline] udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:307 [inline] __udp_tunnel_nic_add_port+0xba9/0xd90 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+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers+0x90/0xd0 net/core/dev.c:2301 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+0xe33/0x1850 net/ipv4/udp_tunnel_nic.c:931 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x18db/0x1f00 net/core/dev.c:11461 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1069 [inline] nsim_create+0xbd7/0x1140 drivers/net/netdevsim/netdev.c:1151 __nsim_dev_port_add+0x7f8/0xcd0 drivers/net/netdevsim/dev.c:1509 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1570 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1622 [inline] nsim_dev_reload_up+0x47d/0x780 drivers/net/netdevsim/dev.c:1058 devlink_reload+0x4b2/0x890 net/devlink/dev.c:475 devlink_nl_reload_doit+0x921/0xc80 net/devlink/dev.c:585 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2687 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2741 __sys_sendmsg net/socket.c:2773 [inline] __do_sys_sendmsg net/socket.c:2778 [inline] __se_sys_sendmsg net/socket.c:2776 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2776 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807afadc00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 168 bytes inside of freed 256-byte region [ffff88807afadc00, ffff88807afadd00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7afac 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 ffff88813fe16b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe16b40 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 20982, tgid 20979 (syz.7.3745), ts 983725386700, free_ts 940638419395 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x24ae/0x2530 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221 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+0x328/0x3c0 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x320/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x464/0x750 mm/slub.c:5308 kmalloc_noprof include/linux/slab.h:954 [inline] io_cache_alloc_new+0x40/0x100 io_uring/alloc_cache.c:40 io_cache_alloc io_uring/alloc_cache.h:61 [inline] io_uring_alloc_async_data io_uring/io_uring.h:354 [inline] io_rw_alloc_async io_uring/rw.c:209 [inline] __io_prep_rw+0x281/0xe70 io_uring/rw.c:268 io_prep_rw io_uring/rw.c:328 [inline] io_prep_write+0x36/0x110 io_uring/rw.c:342 io_init_req io_uring/io_uring.c:1846 [inline] io_submit_sqe io_uring/io_uring.c:1893 [inline] io_submit_sqes+0xbde/0x2310 io_uring/io_uring.c:2061 __do_sys_io_uring_enter io_uring/io_uring.c:2651 [inline] __se_sys_io_uring_enter+0x35b/0x1be0 io_uring/io_uring.c:2600 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 20150 tgid 20150 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5613 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_noprof+0x2b8/0x650 mm/slub.c:4906 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 getname include/linux/fs.h:2537 [inline] getname_maybe_null include/linux/fs.h:2544 [inline] class_filename_maybe_null_constructor include/linux/fs.h:2568 [inline] vfs_fstatat+0x45/0x170 fs/stat.c:368 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807afadb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807afadc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807afadc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807afadd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807afadd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================