kobject: kobject_add_internal failed for hci1:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci1: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xe3/0x180 net/bluetooth/l2cap_sock.c:1720 Read of size 8 at addr ffff888034fcd200 by task kworker/u9:3/5619 CPU: 0 UID: 0 PID: 5619 Comm: kworker/u9:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: hci1 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 l2cap_sock_ready_cb+0xe3/0x180 net/bluetooth/l2cap_sock.c:1720 l2cap_le_start+0x25b/0x1960 net/bluetooth/l2cap_core.c:1391 l2cap_conn_ready net/bluetooth/l2cap_core.c:1644 [inline] l2cap_connect_cfm+0x8d5/0x1560 net/bluetooth/l2cap_core.c:7419 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5891 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312 process_scheduled_works kernel/workqueue.c:3403 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8942: 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:5303 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5315 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2247 sk_alloc+0x3a/0x390 net/core/sock.c:2303 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1934 [inline] l2cap_sock_create+0x147/0x330 net/bluetooth/l2cap_sock.c:1976 bt_sock_create+0x163/0x240 net/bluetooth/af_bluetooth.c:135 __sock_create+0x4e3/0x960 net/socket.c:1679 sock_create net/socket.c:1737 [inline] __sys_socket_create net/socket.c:1774 [inline] __sys_socket+0xd9/0x330 net/socket.c:1821 __do_sys_socket net/socket.c:1835 [inline] __se_sys_socket net/socket.c:1833 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1833 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8941: 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:2700 [inline] slab_free mm/slub.c:6258 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6573 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x74b/0x9d0 net/core/sock.c:2386 l2cap_sock_release+0x1c1/0x270 net/bluetooth/l2cap_sock.c:1463 __sock_release+0xb9/0x250 net/socket.c:726 sock_close+0x1c/0x30 net/socket.c:1529 __fput+0x461/0xa70 fs/file_table.c:510 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:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888034fcd000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 512 bytes inside of freed 2048-byte region [ffff888034fcd000, ffff888034fcd800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34fc8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe16000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe16000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 7210, tgid 7210 (syz-executor), ts 240008670240, free_ts 240004816198 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x27d6/0x2850 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5249 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5e0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7263 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4659 alloc_from_pcs mm/slub.c:4757 [inline] slab_alloc_node mm/slub.c:4891 [inline] __do_kmalloc_node mm/slub.c:5302 [inline] __kmalloc_node_track_caller_noprof+0x60b/0x7e0 mm/slub.c:5415 kmalloc_reserve net/core/skbuff.c:635 [inline] pskb_expand_head+0x230/0x1390 net/core/skbuff.c:2302 netlink_trim+0x1b3/0x2c0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0x80/0xea0 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:9791 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9824 dev_change_flags+0x130/0x270 net/core/dev_api.c:68 ipvlan_set_port_mode+0x140/0x3d0 drivers/net/ipvlan/ipvlan_main.c:-1 ipvlan_link_new+0x723/0xa70 drivers/net/ipvlan/ipvlan_main.c:638 page last free pid 13 tgid 13 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0x1075/0x11b0 mm/page_alloc.c:2938 skb_free_frag include/linux/skbuff.h:3534 [inline] skb_free_head net/core/skbuff.c:1085 [inline] skb_release_data+0x8a5/0xa60 net/core/skbuff.c:1114 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1203 batadv_forw_packet_free+0x65/0x1f0 net/batman-adv/send.c:458 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312 process_scheduled_works kernel/workqueue.c:3403 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: ffff888034fcd100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888034fcd180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888034fcd200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888034fcd280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888034fcd300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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