kobject: kobject_add_internal failed for hci4:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci4: failed to register connection device
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xd7/0x140 net/bluetooth/l2cap_sock.c:1672
Read of size 8 at addr ffff888030d7e188 by task kworker/u9:1/5143

CPU: 0 UID: 0 PID: 5143 Comm: kworker/u9:1 Not tainted 6.13.0-rc1-next-20241205-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: hci4 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 l2cap_sock_ready_cb+0xd7/0x140 net/bluetooth/l2cap_sock.c:1672
 l2cap_chan_ready net/bluetooth/l2cap_core.c:1256 [inline]
 l2cap_le_start+0x4e0/0x17d0 net/bluetooth/l2cap_core.c:1368
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline]
 l2cap_connect_cfm+0x6de/0x1220 net/bluetooth/l2cap_core.c:7278
 hci_connect_cfm+0xa2/0x150 include/net/bluetooth/hci_core.h:2035
 le_conn_complete_evt+0xd3e/0x12e0 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789
 hci_event_func net/bluetooth/hci_event.c:7481 [inline]
 hci_event_packet+0xa55/0x1540 net/bluetooth/hci_event.c:7536
 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4039
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 8974:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4283 [inline]
 __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4295
 kmalloc_noprof include/linux/slab.h:905 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2165
 sk_alloc+0x38/0x370 net/core/sock.c:2218
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1879 [inline]
 l2cap_sock_create+0x13d/0x2f0 net/bluetooth/l2cap_sock.c:1920
 bt_sock_create+0x161/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x4c0/0xa30 net/socket.c:1558
 sock_create net/socket.c:1616 [inline]
 __sys_socket_create net/socket.c:1653 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1700
 __do_sys_socket net/socket.c:1714 [inline]
 __se_sys_socket net/socket.c:1712 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1712
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 8974:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2338 [inline]
 slab_free mm/slub.c:4598 [inline]
 kfree+0x196/0x430 mm/slub.c:4746
 sk_prot_free net/core/sock.c:2201 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2293
 l2cap_sock_release+0x15b/0x1d0 net/bluetooth/l2cap_sock.c:1423
 __sock_release net/socket.c:640 [inline]
 sock_close+0xbc/0x240 net/socket.c:1408
 __fput+0x23c/0xa50 fs/file_table.c:450
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888030d7e000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 392 bytes inside of
 freed 2048-byte region [ffff888030d7e000, ffff888030d7e800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30d78
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801ac42000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801ac42000 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000c35e01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 15609380075, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1549
 prep_new_page mm/page_alloc.c:1557 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3475
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4752
 alloc_pages_mpol+0x30e/0x550 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2408 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2574
 new_slab mm/slub.c:2627 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3815
 __slab_alloc+0x58/0xa0 mm/slub.c:3905
 __slab_alloc_node mm/slub.c:3980 [inline]
 slab_alloc_node mm/slub.c:4141 [inline]
 __do_kmalloc_node mm/slub.c:4282 [inline]
 __kmalloc_node_track_caller_noprof+0x2e9/0x4c0 mm/slub.c:4302
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1323 [inline]
 nlmsg_new include/net/netlink.h:1018 [inline]
 rtmsg_ifinfo_build_skb+0x84/0x260 net/core/rtnetlink.c:4344
 rtmsg_ifinfo_event net/core/rtnetlink.c:4386 [inline]
 rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4395
 register_netdevice+0x1774/0x1b00 net/core/dev.c:10646
 register_netdev+0x3b/0x50 net/core/dev.c:10736
 teql_init+0x6f/0x1d0 net/sched/sch_teql.c:487
 do_one_initcall+0x248/0x870 init/main.c:1266
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888030d7e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888030d7e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888030d7e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888030d7e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888030d7e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================