kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci0: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x22f/0x240 net/bluetooth/l2cap_sock.c:1500 Read of size 8 at addr ffff888020b285a8 by task kworker/u9:8/5830 CPU: 1 UID: 0 PID: 5830 Comm: kworker/u9:8 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci0 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_sock_new_connection_cb+0x22f/0x240 net/bluetooth/l2cap_sock.c:1500 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 Allocated by task 5830: 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 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_noprof+0x33d/0x910 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2245 sk_alloc+0x36/0xe30 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1897 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 7272: 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 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x8b1/0xbc0 net/core/sock.c:2384 sk_destruct+0xc2/0xf0 net/core/sock.c:2412 __sk_free+0xf4/0x3e0 net/core/sock.c:2423 sk_free+0x6a/0x90 net/core/sock.c:2434 sock_put include/net/sock.h:1998 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline] l2cap_sock_kill+0x171/0x350 net/bluetooth/l2cap_sock.c:1250 l2cap_sock_cleanup_listen+0x3d/0x2f0 net/bluetooth/l2cap_sock.c:1465 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 get_signal+0x1d0/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/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 ffff888020b28000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1448 bytes inside of freed 2048-byte region [ffff888020b28000, ffff888020b28800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20b28 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ff27000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ff27000 dead000000000122 0000000000000000 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000082ca01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5830, tgid 5830 (kworker/u9:8), ts 176454530792, free_ts 171930582086 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] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x4fc/0x910 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2245 sk_alloc+0x36/0xe30 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1897 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 page last free pid 7214 tgid 7208 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x130/0x170 mm/slub.c:3886 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_node_track_caller_noprof+0x30b/0x930 mm/slub.c:5764 memdup_user+0x2a/0xe0 mm/util.c:221 memdup_array_user include/linux/string.h:39 [inline] __do_sys_kexec_load kernel/kexec.c:257 [inline] __se_sys_kexec_load kernel/kexec.c:242 [inline] __x64_sys_kexec_load+0x18e/0x230 kernel/kexec.c:242 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888020b28480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020b28500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888020b28580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888020b28600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020b28680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================