kobject: kobject_add_internal failed for hci8:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci8: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x1f9/0x2b0 net/bluetooth/l2cap_sock.c:1500 Read of size 8 at addr ffff888054af27b0 by task kworker/u9:1/11819 CPU: 0 UID: 0 PID: 11819 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci8 hci_rx_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 l2cap_sock_new_connection_cb+0x1f9/0x2b0 net/bluetooth/l2cap_sock.c:1500 l2cap_connect_cfm+0x37a/0x1060 net/bluetooth/l2cap_core.c:7288 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2131 le_conn_complete_evt+0xf65/0x1420 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5847 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7773 hci_rx_work+0x42b/0xf20 net/bluetooth/hci_core.c:4076 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 11819: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5652 [inline] __kmalloc_noprof+0x233/0x7e0 mm/slub.c:5664 kmalloc_noprof include/linux/slab.h:961 [inline] sk_prot_alloc+0xe7/0x220 net/core/sock.c:2245 sk_alloc+0x3a/0x390 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1897 [inline] l2cap_sock_new_connection_cb+0xe2/0x2b0 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x37a/0x1060 net/bluetooth/l2cap_core.c:7288 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2131 le_conn_complete_evt+0xf65/0x1420 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5847 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7773 hci_rx_work+0x42b/0xf20 net/bluetooth/hci_core.c:4076 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 19010: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 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+0x5c/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:6663 [inline] kfree+0x1bd/0x900 mm/slub.c:6871 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x626/0x860 net/core/sock.c:2384 l2cap_sock_cleanup_listen+0xda/0x3e0 net/bluetooth/l2cap_sock.c:1465 l2cap_sock_release+0x6a/0x230 net/bluetooth/l2cap_sock.c:1426 __sock_release net/socket.c:653 [inline] sock_close+0xc3/0x240 net/socket.c:1446 __fput+0x45b/0xa80 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 get_signal+0x11c4/0x1310 kernel/signal.c:2807 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888054af2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1968 bytes inside of freed 2048-byte region [ffff888054af2000, ffff888054af2800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54af0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813ff27000 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813ff27000 0000000000000000 0000000000000001 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 0080000000000003 ffffea000152bc01 00000000ffffffff 00000000ffffffff head: 000000020000003e 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 17014, tgid 17014 (kworker/0:4), ts 1801566443292, free_ts 1801452650378 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xb10/0x1400 mm/slub.c:4651 __slab_alloc+0xc6/0x1f0 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] __do_kmalloc_node mm/slub.c:5651 [inline] __kmalloc_node_track_caller_noprof+0x2ab/0x800 mm/slub.c:5759 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:608 __alloc_skb+0x27e/0x430 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] mld_newpack+0x13c/0xc40 net/ipv6/mcast.c:1775 add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1886 add_grec+0x1452/0x1740 net/ipv6/mcast.c:2025 mld_send_cr net/ipv6/mcast.c:2148 [inline] mld_ifc_work+0x6ed/0xd60 net/ipv6/mcast.c:2693 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 page last free pid 18852 tgid 18852 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xfb6/0x1140 mm/page_alloc.c:2901 discard_slab mm/slub.c:3346 [inline] __put_partials+0x149/0x170 mm/slub.c:3886 __slab_free+0x139/0x210 mm/slub.c:5947 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_noprof+0x181/0x6d0 mm/slub.c:5265 new_handle fs/jbd2/transaction.c:457 [inline] jbd2__journal_start+0x146/0x5b0 fs/jbd2/transaction.c:484 __ext4_journal_start_sb+0x203/0x580 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_dirty_inode+0x93/0x110 fs/ext4/inode.c:6499 __mark_inode_dirty+0x390/0x1330 fs/fs-writeback.c:2587 generic_update_time fs/inode.c:2154 [inline] inode_update_time fs/inode.c:2167 [inline] file_update_time_flags+0x442/0x4f0 fs/inode.c:2394 ext4_page_mkwrite+0x20f/0x1190 fs/ext4/inode.c:6668 do_page_mkwrite+0x150/0x310 mm/memory.c:3489 do_shared_fault mm/memory.c:5792 [inline] do_fault mm/memory.c:5854 [inline] do_pte_missing mm/memory.c:4362 [inline] handle_pte_fault mm/memory.c:6234 [inline] __handle_mm_fault mm/memory.c:6366 [inline] handle_mm_fault+0x124c/0x33d0 mm/memory.c:6535 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 Memory state around the buggy address: ffff888054af2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888054af2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888054af2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888054af2800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888054af2880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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