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: use-after-free in l2cap_sock_new_connection_cb+0x1f5/0x2a0 net/bluetooth/l2cap_sock.c:1520 Read of size 8 at addr ffff88801f2ca548 by task kworker/u5:4/4280 CPU: 0 PID: 4280 Comm: kworker/u5:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: hci2 hci_rx_work Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 l2cap_sock_new_connection_cb+0x1f5/0x2a0 net/bluetooth/l2cap_sock.c:1520 l2cap_connect_cfm+0x35f/0x1120 net/bluetooth/l2cap_core.c:8349 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1814 le_conn_complete_evt+0x10ec/0x1670 net/bluetooth/hci_event.c:5882 hci_le_conn_complete_evt+0x183/0x440 net/bluetooth/hci_event.c:5908 hci_event_func net/bluetooth/hci_event.c:7412 [inline] hci_event_packet+0x7b6/0x1280 net/bluetooth/hci_event.c:7467 hci_rx_work+0x3eb/0xd40 net/bluetooth/hci_core.c:4083 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 4280: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc+0xb0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2052 sk_alloc+0x36/0x340 net/core/sock.c:2108 bt_sock_alloc+0x36/0x130 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1917 [inline] l2cap_sock_new_connection_cb+0xde/0x2a0 net/bluetooth/l2cap_sock.c:1505 l2cap_connect_cfm+0x35f/0x1120 net/bluetooth/l2cap_core.c:8349 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1814 le_conn_complete_evt+0x10ec/0x1670 net/bluetooth/hci_event.c:5882 hci_le_conn_complete_evt+0x183/0x440 net/bluetooth/hci_event.c:5908 hci_event_func net/bluetooth/hci_event.c:7412 [inline] hci_event_packet+0x7b6/0x1280 net/bluetooth/hci_event.c:7467 hci_rx_work+0x3eb/0xd40 net/bluetooth/hci_core.c:4083 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 9094: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700 sk_prot_free net/core/sock.c:2091 [inline] __sk_destruct+0x4ba/0x650 net/core/sock.c:2177 l2cap_sock_cleanup_listen+0xda/0x270 net/bluetooth/l2cap_sock.c:1485 l2cap_sock_release+0x66/0x1e0 net/bluetooth/l2cap_sock.c:1446 __sock_release net/socket.c:654 [inline] sock_close+0xd5/0x240 net/socket.c:1399 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 get_signal+0x11a6/0x1350 kernel/signal.c:2648 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x14f/0x990 kernel/rcu/tree.c:2849 netdev_for_each_tx_queue include/linux/netdevice.h:2465 [inline] dev_shutdown+0x92/0x440 net/sched/sch_generic.c:1492 unregister_netdevice_many+0xa4f/0x1930 net/core/dev.c:10994 default_device_exit_batch+0x9e6/0xa80 net/core/dev.c:11516 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x791/0xba0 net/core/net_namespace.c:640 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x14f/0x990 kernel/rcu/tree.c:2849 netlink_release+0x158e/0x19e0 net/netlink/af_netlink.c:799 __sock_release net/socket.c:654 [inline] sock_release+0x7b/0x140 net/socket.c:682 rtnetlink_net_exit+0x3c/0x60 net/core/rtnetlink.c:6235 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x706/0xba0 net/core/net_namespace.c:640 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88801f2ca000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1352 bytes inside of 2048-byte region [ffff88801f2ca000, ffff88801f2ca800) The buggy address belongs to the physical page: page:ffffea00007cb200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f2c8 head:ffffea00007cb200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888017442000 raw: 0000000000000000 0000000000080008 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 1, tgid 1 (swapper/0), ts 3806590500, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5643 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] acpi_os_allocate_zeroed include/acpi/platform/aclinuxex.h:57 [inline] acpi_ds_create_walk_state+0xe2/0x270 drivers/acpi/acpica/dswstate.c:518 acpi_ps_execute_method+0x21c/0x7b0 drivers/acpi/acpica/psxface.c:134 acpi_ns_evaluate+0x617/0x9d0 drivers/acpi/acpica/nseval.c:205 acpi_ut_evaluate_object+0x12f/0x490 drivers/acpi/acpica/uteval.c:60 acpi_ut_execute_STA+0x44/0x130 drivers/acpi/acpica/uteval.c:223 acpi_ns_get_device_callback+0x210/0x4b0 drivers/acpi/acpica/nsxfeval.c:723 acpi_ns_walk_namespace+0x235/0x680 drivers/acpi/acpica/nswalk.c:-1 page_owner free stack trace missing Memory state around the buggy address: ffff88801f2ca400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f2ca480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801f2ca500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801f2ca580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f2ca600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================