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_sock_new_connection_cb+0x1f9/0x2a0 net/bluetooth/l2cap_sock.c:1484 Read of size 8 at addr ffff88805e8de548 by task kworker/u5:1/5085 CPU: 0 PID: 5085 Comm: kworker/u5:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci2 hci_rx_work Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 l2cap_sock_new_connection_cb+0x1f9/0x2a0 net/bluetooth/l2cap_sock.c:1484 l2cap_connect_cfm+0x375/0x1070 net/bluetooth/l2cap_core.c:7259 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfdc/0x1540 net/bluetooth/hci_event.c:5786 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5812 hci_event_func net/bluetooth/hci_event.c:7454 [inline] hci_event_packet+0x7ba/0x1270 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd60 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 5085: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0xb4/0x230 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2096 sk_alloc+0x3a/0x360 net/core/sock.c:2152 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1881 [inline] l2cap_sock_new_connection_cb+0xe2/0x2a0 net/bluetooth/l2cap_sock.c:1469 l2cap_connect_cfm+0x375/0x1070 net/bluetooth/l2cap_core.c:7259 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfdc/0x1540 net/bluetooth/hci_event.c:5786 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5812 hci_event_func net/bluetooth/hci_event.c:7454 [inline] hci_event_packet+0x7ba/0x1270 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd60 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Freed by task 6113: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 sk_prot_free net/core/sock.c:2135 [inline] __sk_destruct+0x4e0/0x660 net/core/sock.c:2230 l2cap_sock_cleanup_listen+0xda/0x3e0 net/bluetooth/l2cap_sock.c:1449 l2cap_sock_release+0x6a/0x1e0 net/bluetooth/l2cap_sock.c:1410 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1420 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 get_signal+0x1235/0x13f0 kernel/signal.c:2678 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88805e8de000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1352 bytes inside of freed 2048-byte region [ffff88805e8de000, ffff88805e8de800) The buggy address belongs to the physical page: page:ffffea00017a3600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e8d8 head:ffffea00017a3600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c42000 dead000000000100 dead000000000122 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 5129, tgid 5129 (klogd), ts 85470510543, free_ts 27931593026 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4486 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] syslog_print+0x104/0x630 kernel/printk/printk.c:1553 do_syslog+0x575/0x820 kernel/printk/printk.c:1732 __do_sys_syslog kernel/printk/printk.c:1824 [inline] __se_sys_syslog kernel/printk/printk.c:1822 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1822 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 free_contig_range+0xa1/0x150 mm/page_alloc.c:6406 destroy_args+0x80/0x850 mm/debug_vm_pgtable.c:1015 debug_vm_pgtable+0x411/0x440 mm/debug_vm_pgtable.c:1400 do_one_initcall+0x242/0x790 init/main.c:1250 do_initcall_level+0x137/0x1f0 init/main.c:1312 do_initcalls+0x69/0xd0 init/main.c:1328 kernel_init_freeable+0x3ed/0x580 init/main.c:1565 kernel_init+0x1d/0x1c0 init/main.c:1455 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Memory state around the buggy address: ffff88805e8de400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e8de480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805e8de500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805e8de580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e8de600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================