ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 kobject: kobject_add_internal failed for hci1:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci1: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x208/0x2f0 net/bluetooth/l2cap_sock.c:1528 Read of size 8 at addr ffff8880613957b0 by task kworker/u9:4/5831 CPU: 0 UID: 0 PID: 5831 Comm: kworker/u9:4 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: hci1 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 l2cap_sock_new_connection_cb+0x208/0x2f0 net/bluetooth/l2cap_sock.c:1528 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7402 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5891 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312 process_scheduled_works kernel/workqueue.c:3403 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5831: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2247 sk_alloc+0x3a/0x390 net/core/sock.c:2303 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1934 [inline] l2cap_sock_new_connection_cb+0xf1/0x2f0 net/bluetooth/l2cap_sock.c:1513 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7402 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5891 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312 process_scheduled_works kernel/workqueue.c:3403 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 7026: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6561 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x74b/0x9d0 net/core/sock.c:2386 l2cap_sock_cleanup_listen+0xe0/0x440 net/bluetooth/l2cap_sock.c:1490 l2cap_sock_release+0x6e/0x270 net/bluetooth/l2cap_sock.c:1451 __sock_release+0xb9/0x250 net/socket.c:726 sock_close+0x1c/0x30 net/socket.c:1529 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 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+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888061395000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1968 bytes inside of freed 2048-byte region [ffff888061395000, ffff888061395800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888061396000 pfn:0x61390 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000240(workingset|head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000240 ffff88813fe15000 ffff88813fe0fc88 ffffea0000ed7c10 raw: ffff888061396000 0000000800080006 00000000f5000000 0000000000000000 head: 0080000000000240 ffff88813fe15000 ffff88813fe0fc88 ffffea0000ed7c10 head: ffff888061396000 0000000800080006 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5818, tgid 5818 (syz-executor), ts 89160842662, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27d6/0x2850 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kmalloc_node_track_caller_noprof+0x60b/0x7e0 mm/slub.c:5403 kmalloc_reserve net/core/skbuff.c:635 [inline] pskb_expand_head+0x230/0x1390 net/core/skbuff.c:2302 netlink_trim+0x1b3/0x2c0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0x80/0xea0 net/netlink/af_netlink.c:1512 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593 register_netdevice+0x1ada/0x1ed0 net/core/dev.c:11480 cfg80211_register_netdevice+0x138/0x2d0 net/wireless/core.c:1635 ieee80211_if_add+0xeac/0x13d0 net/mac80211/iface.c:2417 ieee80211_register_hw+0x3ebc/0x4a70 net/mac80211/main.c:1641 mac80211_hwsim_new_radio+0x3051/0x54e0 drivers/net/wireless/virtual/mac80211_hwsim.c:6019 page_owner free stack trace missing Memory state around the buggy address: ffff888061395680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888061395700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888061395780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888061395800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888061395880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================