kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci0: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x902/0x1560 net/bluetooth/l2cap_core.c:7419 Read of size 8 at addr ffff88803fefb500 by task kworker/u9:3/5621 CPU: 0 UID: 0 PID: 5621 Comm: kworker/u9:3 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: hci0 hci_rx_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 l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] l2cap_connect_cfm+0x902/0x1560 net/bluetooth/l2cap_core.c:7419 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5891 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 kthread+0x389/0x470 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 5621: 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] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5425 _kmalloc_noprof include/linux/slab.h:967 [inline] _kzalloc_noprof include/linux/slab.h:1284 [inline] l2cap_chan_create+0x51/0x7a0 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1993 [inline] l2cap_sock_new_connection_cb+0x191/0x2f0 net/bluetooth/l2cap_sock.c:1563 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7402 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5891 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 kthread+0x389/0x470 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 Freed by task 7098: 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:2700 [inline] slab_free mm/slub.c:6284 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6599 l2cap_sock_destruct+0x97/0x2c0 net/bluetooth/l2cap_sock.c:1877 __sk_destruct+0x8d/0x9d0 net/core/sock.c:2352 sock_put include/net/sock.h:2019 [inline] l2cap_sock_cleanup_listen+0x1d9/0x580 net/bluetooth/l2cap_sock.c:-1 l2cap_sock_release+0x6e/0x270 net/bluetooth/l2cap_sock.c:1469 __sock_release+0xb9/0x250 net/socket.c:726 sock_close+0x1c/0x30 net/socket.c:1529 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0x560 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803fefb000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1280 bytes inside of freed 2048-byte region [ffff88803fefb000, ffff88803fefb800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803fefe000 pfn:0x3fef8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000240(workingset|head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000240 ffff88813fea7000 ffffea0000ab6c10 ffff88813fea5c88 raw: ffff88803fefe000 0000000800080006 00000000f5000000 0000000000000000 head: 0080000000000240 ffff88813fea7000 ffffea0000ab6c10 ffff88813fea5c88 head: ffff88803fefe000 0000000800080006 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 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 5614, tgid 5614 (syz-executor), ts 98369153456, free_ts 94973941895 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1866 prep_new_page mm/page_alloc.c:1874 [inline] get_page_from_freelist+0x265c/0x26e0 mm/page_alloc.c:3953 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5296 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5e0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7226 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4665 alloc_from_pcs mm/slub.c:4763 [inline] slab_alloc_node mm/slub.c:4897 [inline] __kmalloc_cache_noprof+0x44e/0x690 mm/slub.c:5420 _kmalloc_noprof include/linux/slab.h:967 [inline] _kzalloc_noprof include/linux/slab.h:1284 [inline] rxrpc_alloc_connection+0x7b/0x600 net/rxrpc/conn_object.c:62 rxrpc_prealloc_service_connection+0x26/0x2f0 net/rxrpc/conn_service.c:123 rxrpc_service_prealloc_one+0x2f5/0xe20 net/rxrpc/call_accept.c:86 afs_charge_preallocation+0x394/0x4e0 fs/afs/rxrpc.c:758 afs_open_socket+0x33c/0x3f0 fs/afs/rxrpc.c:112 afs_net_init+0x6ce/0x8f0 fs/afs/main.c:116 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0x118/0x340 net/core/net_namespace.c:446 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:579 page last free pid 5599 tgid 5599 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1413 [inline] __free_frozen_pages+0x10af/0x1190 mm/page_alloc.c:2957 __folio_put+0x2eb/0x3a0 mm/swap.c:112 folio_put include/linux/mm.h:2080 [inline] put_page include/linux/mm.h:2149 [inline] put_netmem include/net/netmem.h:394 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x544/0xa60 net/core/skbuff.c:1108 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1203 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3698 [inline] tcp_ack+0x284f/0x7e00 net/ipv4/tcp_input.c:4370 tcp_rcv_established+0x1533/0x2920 net/ipv4/tcp_input.c:6556 tcp_v4_do_rcv+0x959/0x13f0 net/ipv4/tcp_ipv4.c:1851 sk_backlog_rcv include/net/sock.h:1190 [inline] __release_sock+0x285/0x3d0 net/core/sock.c:3219 __sk_flush_backlog+0x4b/0xe0 net/core/sock.c:3242 sk_flush_backlog include/net/sock.h:1253 [inline] tcp_sendmsg_locked+0x4167/0x5370 net/ipv4/tcp.c:1253 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1452 sock_sendmsg_nosec+0xf9/0x150 net/socket.c:797 __sock_sendmsg net/socket.c:812 [inline] sock_write_iter+0x308/0x410 net/socket.c:1269 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_write+0x156/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff88803fefb400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803fefb480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803fefb500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803fefb580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803fefb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================