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: use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1783 [inline] BUG: KASAN: use-after-free in l2cap_connect_cfm+0x700/0x1120 net/bluetooth/l2cap_core.c:8366 Read of size 8 at addr ffff88801fa7e498 by task kworker/u5:1/8154 CPU: 0 PID: 8154 Comm: kworker/u5:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci1 hci_rx_work Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 l2cap_conn_ready net/bluetooth/l2cap_core.c:1783 [inline] l2cap_connect_cfm+0x700/0x1120 net/bluetooth/l2cap_core.c:8366 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1814 le_conn_complete_evt+0x10ec/0x1670 net/bluetooth/hci_event.c:5882 hci_le_conn_complete_evt+0x183/0x440 net/bluetooth/hci_event.c:5908 hci_event_func net/bluetooth/hci_event.c:7412 [inline] hci_event_packet+0x7b6/0x1280 net/bluetooth/hci_event.c:7467 hci_rx_work+0x3eb/0xd40 net/bluetooth/hci_core.c:4083 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 8154: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] l2cap_chan_create+0x4c/0x760 net/bluetooth/l2cap_core.c:469 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1926 [inline] l2cap_sock_new_connection_cb+0x17e/0x2a0 net/bluetooth/l2cap_sock.c:1505 l2cap_connect_cfm+0x35f/0x1120 net/bluetooth/l2cap_core.c:8349 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1814 le_conn_complete_evt+0x10ec/0x1670 net/bluetooth/hci_event.c:5882 hci_le_conn_complete_evt+0x183/0x440 net/bluetooth/hci_event.c:5908 hci_event_func net/bluetooth/hci_event.c:7412 [inline] hci_event_packet+0x7b6/0x1280 net/bluetooth/hci_event.c:7467 hci_rx_work+0x3eb/0xd40 net/bluetooth/hci_core.c:4083 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 8410: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700 l2cap_sock_cleanup_listen+0xea/0x270 net/bluetooth/l2cap_sock.c:1488 l2cap_sock_release+0x66/0x1e0 net/bluetooth/l2cap_sock.c:1446 __sock_release net/socket.c:654 [inline] sock_close+0xd5/0x240 net/socket.c:1399 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 get_signal+0x11a6/0x1350 kernel/signal.c:2648 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3c0 kernel/workqueue.c:1361 __queue_work+0xba3/0xfb0 kernel/workqueue.c:1520 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1747 [inline] __run_timers+0x569/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 The buggy address belongs to the object at ffff88801fa7e000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1176 bytes inside of 2048-byte region [ffff88801fa7e000, ffff88801fa7e800) The buggy address belongs to the physical page: page:ffffea00007e9e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1fa78 head:ffffea00007e9e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea000076a200 dead000000000002 ffff888017442000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2335679742, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4328 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5614 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956 __do_krealloc mm/slab_common.c:1336 [inline] krealloc+0x6a/0x100 mm/slab_common.c:1369 add_sysfs_param+0xe8/0x930 kernel/params.c:651 kernel_add_sysfs_param+0xaf/0x11b kernel/params.c:812 param_sysfs_builtin+0x20d/0x2ae kernel/params.c:851 param_sysfs_init+0x66/0x6a kernel/params.c:972 do_one_initcall+0x26a/0x840 init/main.c:1310 do_initcall_level+0x137/0x1e4 init/main.c:1383 page_owner free stack trace missing Memory state around the buggy address: ffff88801fa7e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801fa7e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801fa7e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801fa7e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801fa7e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================