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+0x1d4/0x2a8 net/bluetooth/l2cap_sock.c:1500 Read of size 8 at addr ffff0000d36255a8 by task kworker/u9:1/6159 CPU: 1 UID: 0 PID: 6159 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Workqueue: hci2 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_sock_new_connection_cb+0x1d4/0x2a8 net/bluetooth/l2cap_sock.c:1500 l2cap_connect_cfm+0x2d8/0xdb0 net/bluetooth/l2cap_core.c:7288 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2131 le_conn_complete_evt+0xc3c/0x1064 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x114/0x410 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x2dc/0x500 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x6bc/0xf50 net/bluetooth/hci_event.c:7773 hci_rx_work+0x300/0xd80 net/bluetooth/hci_core.c:4076 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Allocated by task 6159: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_noprof+0x410/0x764 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2245 sk_alloc+0x44/0x3a0 net/core/sock.c:2301 bt_sock_alloc+0x4c/0x300 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1897 [inline] l2cap_sock_new_connection_cb+0xe4/0x2a8 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x2d8/0xdb0 net/bluetooth/l2cap_core.c:7288 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2131 le_conn_complete_evt+0xc3c/0x1064 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x114/0x410 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x2dc/0x500 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x6bc/0xf50 net/bluetooth/hci_event.c:7773 hci_rx_work+0x300/0xd80 net/bluetooth/hci_core.c:4076 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Freed by task 7304: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1c4/0x5fc mm/slub.c:6878 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x5fc/0x924 net/core/sock.c:2384 sk_destruct net/core/sock.c:2412 [inline] __sk_free+0x320/0x430 net/core/sock.c:2423 sk_free+0x60/0xc8 net/core/sock.c:2434 sock_put include/net/sock.h:1998 [inline] l2cap_sock_kill+0x12c/0x25c net/bluetooth/l2cap_sock.c:1265 l2cap_sock_cleanup_listen+0xf4/0x2d8 net/bluetooth/l2cap_sock.c:1465 l2cap_sock_release+0x68/0x1fc 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:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0x10c/0x18c kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] exit_to_user_mode_prepare_legacy include/linux/irq-entry-common.h:242 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:81 [inline] el0_svc+0x17c/0x26c arch/arm64/kernel/entry-common.c:725 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 The buggy address belongs to the object at ffff0000d3625000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1448 bytes inside of freed 2048-byte region [ffff0000d3625000, ffff0000d3625800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113620 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0002000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0002000 dead000000000100 dead000000000122 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc34d8801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d3625480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d3625500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000d3625580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d3625600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d3625680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ ODEBUG: assert_init not available (active state 0) object: 0000000097b80a41 object type: timer_list hint: l2cap_chan_timeout+0x0/0x2a8 net/bluetooth/l2cap_core.c:-1 WARNING: lib/debugobjects.c:615 at debug_print_object+0x168/0x1e0 lib/debugobjects.c:612, CPU#1: kworker/u9:1/6159 Modules linked in: CPU: 1 UID: 0 PID: 6159 Comm: kworker/u9:1 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: hci2 hci_rx_work pstate: 634000c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : debug_print_object+0x168/0x1e0 lib/debugobjects.c:612 lr : debug_print_object+0x168/0x1e0 lib/debugobjects.c:612 sp : ffff8000a75b71b0 x29: ffff8000a75b71b0 x28: dfff800000000000 x27: 0000000000000001 x26: ffff80008f871000 x25: dfff800000000000 x24: ffff0000d3624150 x23: ffff80008b5aa820 x22: ffff80008a207484 x21: ffff80008b079660 x20: 0000000000000000 x19: ffff80008b5aa300 x18: 1fffe00033781890 x17: ffff80008a1c31e8 x16: ffff800082e5e68c x15: 0000000000000001 x14: 1ffff00014eb6d6c x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000100000 x10: 0000000000022a94 x9 : 7475b21fe58fcf00 x8 : 7475b21fe58fcf00 x7 : 0000000000000001 x6 : ffff8000805761f8 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002 x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000 Call trace: debug_print_object+0x168/0x1e0 lib/debugobjects.c:612 (P) debug_object_assert_init+0x250/0x2c8 lib/debugobjects.c:1020 debug_timer_assert_init kernel/time/timer.c:803 [inline] debug_assert_init kernel/time/timer.c:848 [inline] __timer_delete+0x48/0x354 kernel/time/timer.c:1366 timer_delete+0x24/0x34 kernel/time/timer.c:1406 try_to_grab_pending kernel/workqueue.c:2061 [inline] work_grab_pending+0xc0/0x830 kernel/workqueue.c:2154 __cancel_work+0x50/0x218 kernel/workqueue.c:4368 cancel_delayed_work+0x24/0x38 kernel/workqueue.c:4456 l2cap_clear_timer include/net/bluetooth/l2cap.h:856 [inline] l2cap_chan_ready net/bluetooth/l2cap_core.c:1252 [inline] l2cap_le_start+0x7ac/0x10c0 net/bluetooth/l2cap_core.c:1376 l2cap_conn_ready net/bluetooth/l2cap_core.c:1629 [inline] l2cap_connect_cfm+0x558/0xdb0 net/bluetooth/l2cap_core.c:7305 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2131 le_conn_complete_evt+0xc3c/0x1064 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x114/0x410 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x2dc/0x500 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x6bc/0xf50 net/bluetooth/hci_event.c:7773 hci_rx_work+0x300/0xd80 net/bluetooth/hci_core.c:4076 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 irq event stamp: 4035 hardirqs last enabled at (4035): [] raw_spin_rq_unlock_irq kernel/sched/sched.h:1570 [inline] hardirqs last enabled at (4035): [] finish_lock_switch+0xb0/0x1c0 kernel/sched/core.c:4995 hardirqs last disabled at (4034): [] __schedule+0x2f8/0x2a7c kernel/sched/core.c:6747 softirqs last enabled at (4020): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (4020): [] release_sock+0x14c/0x1ac net/core/sock.c:3804 softirqs last disabled at (4016): [] spin_lock_bh include/linux/spinlock.h:356 [inline] softirqs last disabled at (4016): [] release_sock+0x34/0x1ac net/core/sock.c:3793 ---[ end trace 0000000000000000 ]--- Unable to handle kernel paging request at virtual address dfff800000000039 KASAN: null-ptr-deref in range [0x00000000000001c8-0x00000000000001cf] Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [dfff800000000039] address between user and kernel address ranges Internal error: Oops: 0000000096000005 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 6159 Comm: kworker/u9:1 Tainted: G B W syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE, [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Workqueue: hci2 hci_rx_work pstate: 63400005 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] pc : do_raw_spin_lock+0x84/0x2cc kernel/locking/spinlock_debug.c:115 lr : __raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline] lr : _raw_spin_lock_bh+0x50/0x60 kernel/locking/spinlock.c:178 sp : ffff8000a75b72c0 x29: ffff8000a75b7350 x28: ffff8000a75b7480 x27: 1fffe0001a6c4804 x26: 1fffe0001a6c4802 x25: 1fffe0001a6c4800 x24: dfff800000000000 x23: 0000000000000002 x22: dfff800000000000 x21: 0000000000000000 x20: 00000000000001cc x19: 00000000000001c8 x18: 1fffe00033781890 x17: ffff80008a1c31e8 x16: ffff8000805448d4 x15: ffff60001a6c4821 x14: 1fffe0001a6c4821 x13: 00000000000000fb x12: ffffffffffffffff x11: 1ffff00014eb6e5c x10: ffff80008f040da7 x9 : f3f3f304f1f1f1f1 x8 : 0000000000000039 x7 : 0000000000000001 x6 : ffff8000891b31dc x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000000 x1 : ffff80008b5a9ce0 x0 : 00000000000001c8 Call trace: debug_spin_lock_before kernel/locking/spinlock_debug.c:-1 [inline] (P) do_raw_spin_lock+0x84/0x2cc kernel/locking/spinlock_debug.c:115 (P) __raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline] _raw_spin_lock_bh+0x50/0x60 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] lock_sock_nested+0x70/0x118 net/core/sock.c:3783 lock_sock include/net/sock.h:1700 [inline] l2cap_sock_ready_cb+0x4c/0x15c net/bluetooth/l2cap_sock.c:1677 l2cap_chan_ready net/bluetooth/l2cap_core.c:1264 [inline] l2cap_le_start+0x950/0x10c0 net/bluetooth/l2cap_core.c:1376 l2cap_conn_ready net/bluetooth/l2cap_core.c:1629 [inline] l2cap_connect_cfm+0x558/0xdb0 net/bluetooth/l2cap_core.c:7305 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2131 le_conn_complete_evt+0xc3c/0x1064 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x114/0x410 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x2dc/0x500 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x6bc/0xf50 net/bluetooth/hci_event.c:7773 hci_rx_work+0x300/0xd80 net/bluetooth/hci_core.c:4076 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Code: aa0003f3 f9000feb f2fe7e69 f8386969 (38f86908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: aa0003f3 mov x19, x0 4: f9000feb str x11, [sp, #24] 8: f2fe7e69 movk x9, #0xf3f3, lsl #48 c: f8386969 str x9, [x11, x24] * 10: 38f86908 ldrsb w8, [x8, x24] <-- trapping instruction