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_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xe47/0x1010 net/bluetooth/l2cap_core.c:7305 Read of size 8 at addr ffff888141ecc480 by task kworker/u9:4/5878 CPU: 0 UID: 0 PID: 5878 Comm: kworker/u9:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci2 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] l2cap_connect_cfm+0xe47/0x1010 net/bluetooth/l2cap_core.c:7305 hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773 hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 5878: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_chan_create+0x44/0x930 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc.constprop.0+0xf5/0x1d0 net/bluetooth/l2cap_sock.c:1906 l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x4f0/0x1010 net/bluetooth/l2cap_core.c:7288 hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773 hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 6802: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6876 l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x1bb/0x310 net/bluetooth/l2cap_core.c:516 l2cap_sock_cleanup_listen+0x4d/0x2f0 net/bluetooth/l2cap_sock.c:1468 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1426 __sock_release+0xb3/0x270 net/socket.c:662 sock_close+0x1c/0x30 net/socket.c:1455 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 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+0xfb/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888141ecc000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff888141ecc000, ffff888141ecc800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x141ec8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 057ff00000000040 ffff88813ff27000 ffffea000509a800 dead000000000002 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 057ff00000000040 ffff88813ff27000 ffffea000509a800 dead000000000002 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 057ff00000000003 ffffea000507b201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 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 2444651083, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x485/0x800 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] acpi_add_single_object+0xbe/0x1bd0 drivers/acpi/scan.c:1876 acpi_bus_check_add+0x23f/0x930 drivers/acpi/scan.c:2181 acpi_ns_walk_namespace+0x498/0x720 drivers/acpi/acpica/nswalk.c:236 acpi_walk_namespace+0xff/0x1d0 drivers/acpi/acpica/nsxfeval.c:606 acpi_bus_scan+0x3e8/0x4a0 drivers/acpi/scan.c:2595 acpi_scan_init+0x244/0x7b0 drivers/acpi/scan.c:2747 acpi_init+0x426/0xb60 drivers/acpi/bus.c:1469 do_one_initcall+0x123/0x680 init/main.c:1378 page_owner free stack trace missing Memory state around the buggy address: ffff888141ecc380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888141ecc400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888141ecc480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888141ecc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888141ecc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================== BUG: KASAN: wild-memory-access in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: wild-memory-access in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: wild-memory-access in l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] BUG: KASAN: wild-memory-access in l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] BUG: KASAN: wild-memory-access in l2cap_connect_cfm+0x80f/0x1010 net/bluetooth/l2cap_core.c:7305 Read of size 4 at addr deacfffffffffc8c by task kworker/u9:4/5878 CPU: 1 UID: 0 PID: 5878 Comm: kworker/u9:4 Tainted: G B syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci2 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 kasan_report+0xe0/0x110 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:194 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] l2cap_connect_cfm+0x80f/0x1010 net/bluetooth/l2cap_core.c:7305 hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773 hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 ================================================================== Oops: general protection fault, probably for non-canonical address 0xfbd59bffffffff91: 0000 [#1] SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdeacfffffffffc88-0xdeacfffffffffc8f] CPU: 1 UID: 0 PID: 5878 Comm: kworker/u9:4 Tainted: G B syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci2 hci_rx_work RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] RIP: 0010:l2cap_connect_cfm+0x816/0x1010 net/bluetooth/l2cap_core.c:7305 Code: 80 fb ff ff 49 39 c5 0f 84 29 01 00 00 e8 f2 5e 46 f7 49 8d 6f 0c be 04 00 00 00 48 89 ef e8 c1 4b af f7 48 89 e8 48 c1 e8 03 <0f> b6 14 18 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 27 RSP: 0018:ffffc9000418f7d8 EFLAGS: 00010213 RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001bbbe000 RDX: 0000000000100000 RSI: ffffffff82279287 RDI: 0000000000000007 RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88807b99c03d R13: ffff888065b08ac0 R14: 0000000000000080 R15: deacfffffffffc80 FS: 0000000000000000(0000) GS:ffff8881249f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556e3ad5c8 CR3: 0000000028e70000 CR4: 0000000000350ef0 Call Trace: hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773 hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] RIP: 0010:l2cap_connect_cfm+0x816/0x1010 net/bluetooth/l2cap_core.c:7305 Code: 80 fb ff ff 49 39 c5 0f 84 29 01 00 00 e8 f2 5e 46 f7 49 8d 6f 0c be 04 00 00 00 48 89 ef e8 c1 4b af f7 48 89 e8 48 c1 e8 03 <0f> b6 14 18 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 27 RSP: 0018:ffffc9000418f7d8 EFLAGS: 00010213 RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001bbbe000 RDX: 0000000000100000 RSI: ffffffff82279287 RDI: 0000000000000007 RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88807b99c03d R13: ffff888065b08ac0 R14: 0000000000000080 R15: deacfffffffffc80 FS: 0000000000000000(0000) GS:ffff8881248f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000001f3030 CR3: 000000007c55e000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 49 39 c5 cmp %rax,%r13 3: 0f 84 29 01 00 00 je 0x132 9: e8 f2 5e 46 f7 call 0xf7465f00 e: 49 8d 6f 0c lea 0xc(%r15),%rbp 12: be 04 00 00 00 mov $0x4,%esi 17: 48 89 ef mov %rbp,%rdi 1a: e8 c1 4b af f7 call 0xf7af4be0 1f: 48 89 e8 mov %rbp,%rax 22: 48 c1 e8 03 shr $0x3,%rax * 26: 0f b6 14 18 movzbl (%rax,%rbx,1),%edx <-- trapping instruction 2a: 48 89 e8 mov %rbp,%rax 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 d0 cmp %dl,%al 35: 7c 08 jl 0x3f 37: 84 d2 test %dl,%dl 39: 0f .byte 0xf 3a: 85 27 test %esp,(%rdi)