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:1623 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x6df/0x1030 net/bluetooth/l2cap_core.c:7275 Read of size 8 at addr ffff88802c3a6480 by task kworker/u5:5/5799 CPU: 1 PID: 5799 Comm: kworker/u5:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: hci2 hci_rx_work Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] l2cap_connect_cfm+0x6df/0x1030 net/bluetooth/l2cap_core.c:7275 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1991 le_conn_complete_evt+0xfb5/0x1500 net/bluetooth/hci_event.c:5772 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5798 hci_event_func net/bluetooth/hci_event.c:7440 [inline] hci_event_packet+0x795/0x1210 net/bluetooth/hci_event.c:7495 hci_rx_work+0x43a/0xd80 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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 5799: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 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:1890 [inline] l2cap_sock_new_connection_cb+0x182/0x2b0 net/bluetooth/l2cap_sock.c:1469 l2cap_connect_cfm+0x375/0x1030 net/bluetooth/l2cap_core.c:7258 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1991 le_conn_complete_evt+0xfb5/0x1500 net/bluetooth/hci_event.c:5772 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5798 hci_event_func net/bluetooth/hci_event.c:7440 [inline] hci_event_packet+0x795/0x1210 net/bluetooth/hci_event.c:7495 hci_rx_work+0x43a/0xd80 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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 6229: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 l2cap_sock_cleanup_listen+0xea/0x3e0 net/bluetooth/l2cap_sock.c:1452 l2cap_sock_release+0x6a/0x1e0 net/bluetooth/l2cap_sock.c:1410 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1421 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 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+0xf6/0x180 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+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x158/0x930 kernel/rcu/tree.c:2837 netlink_release+0x16b4/0x1a80 net/netlink/af_netlink.c:801 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1421 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 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+0xf6/0x180 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+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88802c3a6000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff88802c3a6000, ffff88802c3a6800) The buggy address belongs to the physical page: page:ffffea0000b0e800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c3a0 head:ffffea0000b0e800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017842000 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080080008 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5792, tgid 5792 (syz-executor), ts 83234572049, free_ts 83193563752 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2e0 mm/slub.c:2081 ___slab_alloc+0xc6d/0x1300 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+0x1a2/0x260 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+0x117/0x260 net/core/skbuff.c:581 pskb_expand_head+0x185/0x1230 net/core/skbuff.c:2099 netlink_trim+0x180/0x220 net/netlink/af_netlink.c:1301 netlink_broadcast_filtered+0x80/0x1110 net/netlink/af_netlink.c:1515 netlink_broadcast net/netlink/af_netlink.c:1560 [inline] nlmsg_multicast include/net/netlink.h:1090 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2588 rtnl_notify net/core/rtnetlink.c:800 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4093 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4109 [inline] rtnetlink_event+0x224/0x260 net/core/rtnetlink.c:6526 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 __netdev_upper_dev_link+0x3c4/0x580 net/core/dev.c:7796 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x31d/0x410 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] ref_tracker_alloc+0x134/0x460 lib/ref_tracker.c:203 __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline] netdev_hold include/linux/netdevice.h:4139 [inline] netdev_queue_add_kobject net/core/net-sysfs.c:1690 [inline] netdev_queue_update_kobjects+0x191/0x480 net/core/net-sysfs.c:1745 register_queue_kobjects net/core/net-sysfs.c:1806 [inline] netdev_register_kobject+0x269/0x310 net/core/net-sysfs.c:2046 register_netdevice+0x128f/0x1ae0 net/core/dev.c:10280 veth_newlink+0x7bb/0xc30 drivers/net/veth.c:1902 Memory state around the buggy address: ffff88802c3a6380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802c3a6400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802c3a6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802c3a6500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802c3a6580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================