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:1616 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x86a/0x1390 net/bluetooth/l2cap_core.c:7368 Read of size 8 at addr ffff888021693480 by task kworker/u9:7/7196 CPU: 1 UID: 0 PID: 7196 Comm: kworker/u9:7 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci2 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1616 [inline] l2cap_connect_cfm+0x86a/0x1390 net/bluetooth/l2cap_core.c:7368 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0xf65/0x1430 net/bluetooth/hci_event.c:5847 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5873 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x7af/0x12c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 7196: 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+0x31c/0x660 mm/slub.c:5383 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] l2cap_chan_create+0x51/0x790 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1931 [inline] l2cap_sock_new_connection_cb+0x182/0x2e0 net/bluetooth/l2cap_sock.c:1510 l2cap_connect_cfm+0x368/0x1390 net/bluetooth/l2cap_core.c:7351 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0xf65/0x1430 net/bluetooth/hci_event.c:5847 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5873 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x7af/0x12c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 8143: 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:2692 [inline] slab_free mm/slub.c:6168 [inline] kfree+0x1c1/0x630 mm/slub.c:6486 l2cap_sock_cleanup_listen+0xf0/0x440 net/bluetooth/l2cap_sock.c:1493 l2cap_sock_release+0x6a/0x230 net/bluetooth/l2cap_sock.c:1451 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x44f/0xa70 fs/file_table.c:469 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+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888021693000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff888021693000, ffff888021693800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888021695000 pfn:0x21690 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88813fea9000 ffff88813fea3948 ffffea000089b810 raw: ffff888021695000 0000000800080007 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88813fea9000 ffff88813fea3948 ffffea000089b810 head: ffff888021695000 0000000800080007 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000085a401 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 5836, tgid 5836 (syz-executor), ts 93413916868, free_ts 93391309040 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3296 [inline] allocate_slab+0x77/0x660 mm/slub.c:3485 new_slab mm/slub.c:3543 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7178 __pcs_replace_empty_main+0x2f9/0x5e0 mm/slub.c:-1 alloc_from_pcs mm/slub.c:4720 [inline] slab_alloc_node mm/slub.c:4854 [inline] __do_kmalloc_node mm/slub.c:5262 [inline] __kmalloc_node_track_caller_noprof+0x572/0x7b0 mm/slub.c:5371 kmalloc_reserve net/core/skbuff.c:635 [inline] pskb_expand_head+0x228/0x1320 net/core/skbuff.c:2315 netlink_trim+0x1b3/0x2c0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0xd6/0x1020 net/netlink/af_netlink.c:1512 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:2593 __dev_notify_flags+0xf2/0x310 net/core/dev.c:9799 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9832 do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3158 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 page last free pid 2 tgid 2 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5576 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4921 alloc_task_struct_node kernel/fork.c:185 [inline] dup_task_struct+0x57/0x9a0 kernel/fork.c:916 copy_process+0x508/0x3cf0 kernel/fork.c:2050 kernel_clone+0x248/0x8e0 kernel/fork.c:2654 kernel_thread+0x13f/0x1b0 kernel/fork.c:2715 create_kthread kernel/kthread.c:459 [inline] kthreadd+0x4ec/0x6e0 kernel/kthread.c:817 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888021693380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021693400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888021693480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021693500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021693580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================