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_sock_new_connection_cb+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1525 Read of size 8 at addr ffff888075d335a8 by task kworker/u9:2/14549 CPU: 0 UID: 0 PID: 14549 Comm: kworker/u9:2 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: hci0 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_sock_new_connection_cb+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1525 l2cap_connect_cfm+0x368/0x1390 net/bluetooth/l2cap_core.c:7363 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/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 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 14549: 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] __do_kmalloc_node mm/slub.c:5262 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5274 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2245 sk_alloc+0x3a/0x390 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1922 [inline] l2cap_sock_new_connection_cb+0xe2/0x2e0 net/bluetooth/l2cap_sock.c:1510 l2cap_connect_cfm+0x368/0x1390 net/bluetooth/l2cap_core.c:7363 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/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 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 16480: 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:6167 [inline] kfree+0x1c1/0x630 mm/slub.c:6485 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x623/0x880 net/core/sock.c:2384 l2cap_sock_cleanup_listen+0xe0/0x440 net/bluetooth/l2cap_sock.c:1490 l2cap_sock_release+0x6a/0x230 net/bluetooth/l2cap_sock.c:1451 __sock_release+0xb9/0x250 net/socket.c:731 sock_close+0x1c/0x30 net/socket.c:1535 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11eb/0x1330 kernel/signal.c:2805 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [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 ffff888075d33000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1448 bytes inside of freed 2048-byte region [ffff888075d33000, ffff888075d33800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75d30 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 ffff88801b034000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b034000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001d74c01 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5826, tgid 5826 (syz-executor), ts 107538756097, free_ts 107521866184 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1892 prep_new_page mm/page_alloc.c:1900 [inline] get_page_from_freelist+0x23a1/0x2440 mm/page_alloc.c:3965 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5253 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:7177 refill_sheaf mm/slub.c:2818 [inline] __pcs_replace_empty_main+0x2cd/0x650 mm/slub.c:4618 alloc_from_pcs mm/slub.c:4719 [inline] slab_alloc_node mm/slub.c:4853 [inline] __do_kmalloc_node mm/slub.c:5261 [inline] __kmalloc_node_track_caller_noprof+0x572/0x7b0 mm/slub.c:5370 kmalloc_reserve net/core/skbuff.c:635 [inline] pskb_expand_head+0x228/0x1320 net/core/skbuff.c:2304 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 rtnl_notify net/core/rtnetlink.c:958 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4436 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4452 [inline] rtnetlink_event+0x224/0x270 net/core/rtnetlink.c:7018 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] netif_set_mac_address+0x39f/0x4e0 net/core/dev.c:10004 do_setlink+0x9b1/0x4590 net/core/rtnetlink.c:3110 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 page last free pid 5823 tgid 5823 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1436 [inline] __free_frozen_pages+0xbe2/0xd60 mm/page_alloc.c:2981 __slab_free+0x263/0x2b0 mm/slub.c:5575 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:4868 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4875 alloc_filename fs/namei.c:142 [inline] do_getname_kernel+0x54/0x230 fs/namei.c:261 getname_kernel fs/namei.c:284 [inline] class_filename_kernel_constructor include/linux/fs.h:2540 [inline] kern_path+0x25/0x150 fs/namei.c:3039 tomoyo_mount_acl security/tomoyo/mount.c:138 [inline] tomoyo_mount_permission+0x795/0x9d0 security/tomoyo/mount.c:239 security_sb_mount+0xe4/0x320 security/security.c:1062 path_mount+0xbc/0x10e0 fs/namespace.c:4101 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888075d33480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888075d33500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888075d33580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888075d33600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888075d33680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================