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_conn_ready net/bluetooth/l2cap_core.c:1616 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xe57/0x1050 net/bluetooth/l2cap_core.c:7323 Read of size 8 at addr ffff88805d423480 by task kworker/u9:2/30228 CPU: 1 UID: 0 PID: 30228 Comm: kworker/u9:2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: hci0 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1616 [inline] l2cap_connect_cfm+0xe57/0x1050 net/bluetooth/l2cap_core.c:7323 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 30228: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] l2cap_chan_create+0x44/0x940 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc.constprop.0+0xf5/0x1e0 net/bluetooth/l2cap_sock.c:1924 l2cap_sock_new_connection_cb+0x101/0x260 net/bluetooth/l2cap_sock.c:1503 l2cap_connect_cfm+0x4e2/0x1050 net/bluetooth/l2cap_core.c:7306 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 1195: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2670 [inline] slab_free mm/slub.c:6082 [inline] kfree+0x1aa/0x670 mm/slub.c:6399 l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x235/0x300 net/bluetooth/l2cap_core.c:516 l2cap_sock_cleanup_listen+0x4d/0x2d0 net/bluetooth/l2cap_sock.c:1486 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1444 __sock_release+0xb3/0x260 net/socket.c:662 sock_close+0x1c/0x30 net/socket.c:1455 __fput+0x3ff/0xb40 fs/file_table.c:469 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:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __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 include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805d423000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff88805d423000, ffff88805d423800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d420 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 ffff88813fe33000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe33000 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001750801 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 28279, tgid 28270 (syz.3.5416), ts 2024491927832, free_ts 1982102188387 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1883 prep_new_page mm/page_alloc.c:1891 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3956 __alloc_frozen_pages_noprof+0x27d/0x2ae0 mm/page_alloc.c:5244 alloc_slab_page mm/slub.c:3238 [inline] allocate_slab mm/slub.c:3411 [inline] new_slab+0xa6/0x6e0 mm/slub.c:3469 refill_objects+0x26b/0x400 mm/slub.c:7091 refill_sheaf mm/slub.c:2787 [inline] alloc_full_sheaf mm/slub.c:2808 [inline] __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4546 alloc_from_pcs mm/slub.c:4639 [inline] slab_alloc_node mm/slub.c:4773 [inline] __do_kmalloc_node mm/slub.c:5176 [inline] __kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5285 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635 __alloc_skb+0x185/0x710 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] __ip_append_data+0x2ec7/0x46d0 net/ipv4/ip_output.c:1133 ip_append_data net/ipv4/ip_output.c:1378 [inline] ip_append_data+0x10f/0x1a0 net/ipv4/ip_output.c:1357 udp_sendmsg+0xa62/0x2890 net/ipv4/udp.c:1511 inet_sendmsg+0x105/0x140 net/ipv4/af_inet.c:859 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_write_iter+0x509/0x610 net/socket.c:1195 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x1f8/0x250 fs/read_write.c:740 page last free pid 5788 tgid 5788 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1432 [inline] __free_frozen_pages+0x7bb/0x1090 mm/page_alloc.c:2972 __folio_put+0x3b4/0x540 mm/swap.c:112 folio_put include/linux/mm.h:1616 [inline] put_page include/linux/mm.h:1685 [inline] put_netmem include/net/netmem.h:420 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x667/0x9d0 net/core/skbuff.c:1122 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb+0x4f/0x70 net/core/skbuff.c:1217 tcp_wmem_free_skb include/net/tcp.h:335 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:2266 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3698 [inline] tcp_ack+0x2072/0x74f0 net/ipv4/tcp_input.c:4366 tcp_rcv_established+0x10d7/0x38c0 net/ipv4/tcp_input.c:6610 tcp_v4_do_rcv+0xc64/0x10a0 net/ipv4/tcp_ipv4.c:1880 tcp_v4_rcv+0x2de5/0x4680 net/ipv4/tcp_ipv4.c:2315 ip_protocol_deliver_rcu+0xba/0x4d0 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x3f2/0x6e0 net/ipv4/ip_input.c:241 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x19a/0x1f0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:584 [inline] ip_list_rcv_finish+0xbee/0x1240 net/ipv4/ip_input.c:636 ip_sublist_rcv net/ipv4/ip_input.c:644 [inline] ip_list_rcv+0x338/0x450 net/ipv4/ip_input.c:678 __netif_receive_skb_list_ptype net/core/dev.c:6192 [inline] __netif_receive_skb_list_core+0x74c/0x940 net/core/dev.c:6239 __netif_receive_skb_list net/core/dev.c:6291 [inline] netif_receive_skb_list_internal+0x722/0xd40 net/core/dev.c:6382 gro_normal_list include/net/gro.h:523 [inline] gro_normal_list include/net/gro.h:519 [inline] gro_flush_normal include/net/gro.h:531 [inline] napi_complete_done+0x221/0x940 net/core/dev.c:6751 Memory state around the buggy address: ffff88805d423380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d423400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805d423480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805d423500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d423580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================