kobject: kobject_add_internal failed for hci2:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci2: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x6df/0x1070 net/bluetooth/l2cap_core.c:7319 Read of size 8 at addr ffff88807a2de480 by task kworker/u5:4/5775 CPU: 1 PID: 5775 Comm: kworker/u5:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci2 hci_rx_work Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] l2cap_connect_cfm+0x6df/0x1070 net/bluetooth/l2cap_core.c:7319 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfdc/0x1540 net/bluetooth/hci_event.c:5786 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5812 hci_event_func net/bluetooth/hci_event.c:7454 [inline] hci_event_packet+0x7ba/0x1270 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd60 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 5775: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] l2cap_chan_create+0x50/0x760 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1897 [inline] l2cap_sock_new_connection_cb+0x182/0x2a0 net/bluetooth/l2cap_sock.c:1476 l2cap_connect_cfm+0x375/0x1070 net/bluetooth/l2cap_core.c:7302 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfdc/0x1540 net/bluetooth/hci_event.c:5786 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5812 hci_event_func net/bluetooth/hci_event.c:7454 [inline] hci_event_packet+0x7ba/0x1270 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd60 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Freed by task 7320: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 l2cap_sock_cleanup_listen+0xea/0x3e0 net/bluetooth/l2cap_sock.c:1459 l2cap_sock_release+0x6a/0x1e0 net/bluetooth/l2cap_sock.c:1417 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1420 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x950 kernel/rcu/tree.c:2837 netdev_for_each_tx_queue include/linux/netdevice.h:2520 [inline] dev_shutdown+0x96/0x440 net/sched/sch_generic.c:1492 unregister_netdevice_many_notify+0x8e0/0x1900 net/core/dev.c:11102 unregister_netdevice_many net/core/dev.c:11168 [inline] unregister_netdevice_queue+0x32c/0x370 net/core/dev.c:11048 unregister_netdevice include/linux/netdevice.h:3137 [inline] __tun_detach+0xd45/0x1500 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x10d/0x1c0 drivers/net/tun.c:3511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807a2de000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff88807a2de000, ffff88807a2de800) The buggy address belongs to the physical page: page:ffffea0001e8b600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807a2dd000 pfn:0x7a2d8 head:ffffea0001e8b600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c42000 ffffea00050ca400 dead000000000002 raw: ffff88807a2dd000 0000000080080007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1079, tgid 1079 (kworker/u4:6), ts 76717217496, free_ts 76708255334 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1316 [inline] mld_newpack+0x154/0xbe0 net/ipv6/mcast.c:1743 add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1854 add_grec+0x13ad/0x1660 net/ipv6/mcast.c:1992 mld_send_initial_cr+0xed/0x240 net/ipv6/mcast.c:2237 ipv6_mc_dad_complete+0x88/0x210 net/ipv6/mcast.c:2248 addrconf_dad_completed+0x776/0xd90 net/ipv6/addrconf.c:4322 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 __slab_free+0x35a/0x400 mm/slub.c:3736 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc_lru+0x111/0x2d0 mm/slub.c:3526 alloc_inode_sb include/linux/fs.h:2946 [inline] sock_alloc_inode+0x28/0xc0 net/socket.c:308 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x63/0x1d0 fs/inode.c:1049 sock_alloc net/socket.c:634 [inline] __sock_create+0x12d/0x940 net/socket.c:1534 sock_create net/socket.c:1626 [inline] __sys_socket_create net/socket.c:1663 [inline] __sys_socket+0xd7/0x1a0 net/socket.c:1714 __do_sys_socket net/socket.c:1728 [inline] __se_sys_socket net/socket.c:1726 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1726 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88807a2de380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a2de400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807a2de480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807a2de500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a2de580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================