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_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x574/0xd40 net/bluetooth/l2cap_core.c:7304 Read of size 8 at addr ffff0000f289f480 by task kworker/u9:4/6560 CPU: 1 UID: 0 PID: 6560 Comm: kworker/u9:4 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Workqueue: hci4 hci_rx_work Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xa8/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0xb0/0x110 mm/kasan/report.c:595 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] l2cap_connect_cfm+0x574/0xd40 net/bluetooth/l2cap_core.c:7304 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2106 le_conn_complete_evt+0xcc0/0x1184 net/bluetooth/hci_event.c:5785 hci_le_conn_complete_evt+0x114/0x3f8 net/bluetooth/hci_event.c:5811 hci_le_meta_evt+0x2cc/0x4b0 net/bluetooth/hci_event.c:7248 hci_event_func net/bluetooth/hci_event.c:7556 [inline] hci_event_packet+0x6bc/0xf04 net/bluetooth/hci_event.c:7613 hci_rx_work+0x320/0xb18 net/bluetooth/hci_core.c:4099 process_one_work+0x7e8/0x155c kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3427 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Allocated by task 6560: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:77 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:573 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x3a4/0x65c mm/slub.c:5748 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_chan_create+0x58/0x698 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1906 [inline] l2cap_sock_new_connection_cb+0x164/0x284 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x2d8/0xd40 net/bluetooth/l2cap_core.c:7287 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2106 le_conn_complete_evt+0xcc0/0x1184 net/bluetooth/hci_event.c:5785 hci_le_conn_complete_evt+0x114/0x3f8 net/bluetooth/hci_event.c:5811 hci_le_meta_evt+0x2cc/0x4b0 net/bluetooth/hci_event.c:7248 hci_event_func net/bluetooth/hci_event.c:7556 [inline] hci_event_packet+0x6bc/0xf04 net/bluetooth/hci_event.c:7613 hci_rx_work+0x320/0xb18 net/bluetooth/hci_core.c:4099 process_one_work+0x7e8/0x155c kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3427 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Freed by task 8000: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:77 __kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2523 [inline] slab_free mm/slub.c:6611 [inline] kfree+0x184/0x600 mm/slub.c:6818 l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x174/0x24c net/bluetooth/l2cap_core.c:515 l2cap_sock_cleanup_listen+0x104/0x28c net/bluetooth/l2cap_sock.c:1468 l2cap_sock_release+0x68/0x1d8 net/bluetooth/l2cap_sock.c:1426 __sock_release net/socket.c:662 [inline] sock_close+0xa0/0x1e4 net/socket.c:1455 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x524/0x1a14 kernel/exit.c:966 do_group_exit+0x194/0x22c kernel/exit.c:1107 get_signal+0x11dc/0x12f8 kernel/signal.c:3034 arch_do_signal_or_restart+0x274/0x4414 arch/arm64/kernel/signal.c:1619 exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline] el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 The buggy address belongs to the object at ffff0000f289f000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff0000f289f000, ffff0000f289f800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x132898 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0002000 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0002000 0000000000000000 dead000000000001 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc3ca2601 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f289f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f289f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000f289f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f289f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f289f580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address fbd51fffffffff91 KASAN: maybe wild-memory-access in range [0xdeacfffffffffc88-0xdeacfffffffffc8f] Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [fbd51fffffffff91] address between user and kernel address ranges Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 1 UID: 0 PID: 6560 Comm: kworker/u9:4 Tainted: G B syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Workqueue: hci4 hci_rx_work pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] pc : atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] pc : l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] pc : l2cap_conn_ready net/bluetooth/l2cap_core.c:1625 [inline] pc : l2cap_connect_cfm+0x50c/0xd40 net/bluetooth/l2cap_core.c:7304 lr : instrument_atomic_read include/linux/instrumented.h:68 [inline] lr : atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] lr : l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] lr : l2cap_conn_ready net/bluetooth/l2cap_core.c:1625 [inline] lr : l2cap_connect_cfm+0x500/0xd40 net/bluetooth/l2cap_core.c:7304 sp : ffff8000a4b77540 x29: ffff8000a4b775e0 x28: dfff800000000000 x27: 1fffe0001b661807 x26: ffff0000d4b8001a x25: 0000000000000080 x24: deacfffffffffc8c x23: 1fffe0001a970003 x22: dead000000000100 x21: ffff0000d4b802c0 x20: ffff0000db30c03d x19: ffff0000d4b80000 x18: 1fffe000337dfe90 x17: 3d3d3d3d3d3d3d3d x16: ffff800082de9540 x15: 0000000000000001 x14: 1ffff000125cd514 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000100000 x10: fffffffffffffff8 x9 : 0000000000000007 x8 : 1bd59fffffffff91 x7 : 0000000000000001 x6 : ffff8000805638d4 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff80008a0a0e6c x2 : 0000000000000000 x1 : 0000000000000004 x0 : 0000000000000001 Call trace: raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] (P) atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] (P) l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] (P) l2cap_conn_ready net/bluetooth/l2cap_core.c:1625 [inline] (P) l2cap_connect_cfm+0x50c/0xd40 net/bluetooth/l2cap_core.c:7304 (P) hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2106 le_conn_complete_evt+0xcc0/0x1184 net/bluetooth/hci_event.c:5785 hci_le_conn_complete_evt+0x114/0x3f8 net/bluetooth/hci_event.c:5811 hci_le_meta_evt+0x2cc/0x4b0 net/bluetooth/hci_event.c:7248 hci_event_func net/bluetooth/hci_event.c:7556 [inline] hci_event_packet+0x6bc/0xf04 net/bluetooth/hci_event.c:7613 hci_rx_work+0x320/0xb18 net/bluetooth/hci_core.c:4099 process_one_work+0x7e8/0x155c kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3427 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Code: 978457ed d343ff08 12000b09 11000d29 (38fc6908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 978457ed bl 0xfffffffffe115fb4 4: d343ff08 lsr x8, x24, #3 8: 12000b09 and w9, w24, #0x7 c: 11000d29 add w9, w9, #0x3 * 10: 38fc6908 ldrsb w8, [x8, x28] <-- trapping instruction