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: use-after-free in l2cap_sock_new_connection_cb+0x1f5/0x2a0 net/bluetooth/l2cap_sock.c:1527 Read of size 8 at addr ffff888060f13548 by task kworker/u5:1/3456 CPU: 1 PID: 3456 Comm: kworker/u5:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci2 hci_rx_work Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 l2cap_sock_new_connection_cb+0x1f5/0x2a0 net/bluetooth/l2cap_sock.c:1527 l2cap_connect_cfm+0x35f/0x1120 net/bluetooth/l2cap_core.c:8392 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1814 le_conn_complete_evt+0x10ec/0x1670 net/bluetooth/hci_event.c:5882 hci_le_conn_complete_evt+0x183/0x440 net/bluetooth/hci_event.c:5908 hci_event_func net/bluetooth/hci_event.c:7412 [inline] hci_event_packet+0x7b6/0x1280 net/bluetooth/hci_event.c:7467 hci_rx_work+0x3eb/0xd40 net/bluetooth/hci_core.c:4083 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 3456: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc+0xb0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2052 sk_alloc+0x36/0x340 net/core/sock.c:2108 bt_sock_alloc+0x36/0x130 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1924 [inline] l2cap_sock_new_connection_cb+0xde/0x2a0 net/bluetooth/l2cap_sock.c:1512 l2cap_connect_cfm+0x35f/0x1120 net/bluetooth/l2cap_core.c:8392 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1814 le_conn_complete_evt+0x10ec/0x1670 net/bluetooth/hci_event.c:5882 hci_le_conn_complete_evt+0x183/0x440 net/bluetooth/hci_event.c:5908 hci_event_func net/bluetooth/hci_event.c:7412 [inline] hci_event_packet+0x7b6/0x1280 net/bluetooth/hci_event.c:7467 hci_rx_work+0x3eb/0xd40 net/bluetooth/hci_core.c:4083 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 4401: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700 sk_prot_free net/core/sock.c:2091 [inline] __sk_destruct+0x4ba/0x650 net/core/sock.c:2177 l2cap_sock_cleanup_listen+0xda/0x270 net/bluetooth/l2cap_sock.c:1492 l2cap_sock_release+0x66/0x1e0 net/bluetooth/l2cap_sock.c:1453 __sock_release net/socket.c:654 [inline] sock_close+0xd5/0x240 net/socket.c:1399 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 get_signal+0x11a6/0x1350 kernel/signal.c:2648 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871 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:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x14f/0x990 kernel/rcu/tree.c:2849 netlink_release+0x158e/0x19e0 net/netlink/af_netlink.c:799 __sock_release net/socket.c:654 [inline] sock_close+0xd5/0x240 net/socket.c:1399 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888060f13000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1352 bytes inside of 2048-byte region [ffff888060f13000, ffff888060f13800) The buggy address belongs to the physical page: page:ffffea000183c400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x60f10 head:ffffea000183c400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001241800 dead000000000002 ffff888017442000 raw: 0000000000000000 0000000000080008 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 504, tgid 504 (kworker/0:4), ts 2464641313902, free_ts 2445851767263 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x22a/0x7e0 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1303 [inline] mld_newpack+0x12f/0xc00 net/ipv6/mcast.c:1745 add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1856 add_grec+0x13b2/0x1660 net/ipv6/mcast.c:1994 mld_send_cr net/ipv6/mcast.c:2120 [inline] mld_ifc_work+0x6e7/0xb40 net/ipv6/mcast.c:2658 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1486 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] kmem_cache_alloc_node+0x14d/0x320 mm/slub.c:3404 __alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1303 [inline] alloc_skb_with_frags+0xa7/0x710 net/core/skbuff.c:6164 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2755 unix_dgram_sendmsg+0x539/0x16e0 net/unix/af_unix.c:1945 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] sock_write_iter+0x2d9/0x3e0 net/socket.c:1143 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4b1/0xa30 fs/read_write.c:584 ksys_write+0x14c/0x250 fs/read_write.c:637 Memory state around the buggy address: ffff888060f13400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888060f13480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888060f13500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888060f13580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888060f13600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================