kobject: kobject_add_internal failed for hci3:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci3: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x6e4/0x1040 net/bluetooth/l2cap_core.c:7304 Read of size 8 at addr ffff88803308d480 by task kworker/u9:5/5854 CPU: 0 UID: 0 PID: 5854 Comm: kworker/u9:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: hci3 hci_rx_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] l2cap_connect_cfm+0x6e4/0x1040 net/bluetooth/l2cap_core.c:7304 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2106 le_conn_complete_evt+0xfb8/0x1500 net/bluetooth/hci_event.c:5785 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5811 hci_event_func net/bluetooth/hci_event.c:7556 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7613 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4099 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5854: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5724 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_chan_create+0x50/0x760 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1906 [inline] l2cap_sock_new_connection_cb+0x182/0x2b0 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x37a/0x1040 net/bluetooth/l2cap_core.c:7287 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2106 le_conn_complete_evt+0xfb8/0x1500 net/bluetooth/hci_event.c:5785 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5811 hci_event_func net/bluetooth/hci_event.c:7556 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7613 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4099 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 14834: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2514 [inline] slab_free mm/slub.c:6566 [inline] kfree+0x19a/0x6d0 mm/slub.c:6773 l2cap_sock_cleanup_listen+0xea/0x3e0 net/bluetooth/l2cap_sock.c:1468 l2cap_sock_release+0x6a/0x210 net/bluetooth/l2cap_sock.c:1426 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 get_signal+0x11ec/0x1340 kernel/signal.c:2807 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803308d000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff88803308d000, ffff88803308d800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33088 head: order:3 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 ffff88813fe27000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe27000 dead000000000100 dead000000000122 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000cc2201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5834, tgid 5834 (syz-executor), ts 98436872659, free_ts 98403522419 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3030 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3203 new_slab mm/slub.c:3257 [inline] ___slab_alloc+0xe94/0x1920 mm/slub.c:4627 __slab_alloc+0x65/0x100 mm/slub.c:4746 __slab_alloc_node mm/slub.c:4822 [inline] slab_alloc_node mm/slub.c:5233 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5712 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 pskb_expand_head+0x18e/0x1150 net/core/skbuff.c:2241 netlink_trim+0x1d5/0x2e0 net/netlink/af_netlink.c:1301 netlink_broadcast_filtered+0xd6/0x1000 net/netlink/af_netlink.c:1514 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2595 __dev_notify_flags+0xf4/0x2e0 net/core/dev.c:9672 rtnl_configure_link net/core/rtnetlink.c:3599 [inline] rtnl_newlink_create+0x61c/0xb00 net/core/rtnetlink.c:3843 __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0x16e4/0x1c80 net/core/rtnetlink.c:4065 page last free pid 5842 tgid 5842 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 __slab_free+0x2e7/0x390 mm/slub.c:5923 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] __kmalloc_cache_noprof+0x36f/0x6f0 mm/slub.c:5719 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ref_tracker_alloc+0x133/0x460 lib/ref_tracker.c:271 __netdev_tracker_alloc include/linux/netdevice.h:4375 [inline] netdev_hold include/linux/netdevice.h:4404 [inline] netdev_queue_add_kobject net/core/net-sysfs.c:1994 [inline] netdev_queue_update_kobjects+0x1d1/0x6c0 net/core/net-sysfs.c:2056 register_queue_kobjects net/core/net-sysfs.c:2119 [inline] netdev_register_kobject+0x258/0x310 net/core/net-sysfs.c:2362 register_netdevice+0x126c/0x1ae0 net/core/dev.c:11294 veth_newlink+0x5d4/0xa60 drivers/net/veth.c:1884 rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3833 __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0x16e4/0x1c80 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6954 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 Memory state around the buggy address: ffff88803308d380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803308d400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803308d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803308d500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803308d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================