ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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:1623 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x6e4/0x1040 net/bluetooth/l2cap_core.c:7304 Read of size 8 at addr ffff888030475480 by task kworker/u9:3/6285 CPU: 1 UID: 0 PID: 6285 Comm: kworker/u9:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: hci0 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_conn_ready net/bluetooth/l2cap_core.c:1623 [inline] l2cap_connect_cfm+0x6e4/0x1040 net/bluetooth/l2cap_core.c:7304 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2107 le_conn_complete_evt+0xfb8/0x1500 net/bluetooth/hci_event.c:5792 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5818 hci_event_func net/bluetooth/hci_event.c:7563 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7620 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4099 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x1790 kernel/workqueue.c:3346 worker_thread+0xa57/0xfc0 kernel/workqueue.c:3427 kthread+0x711/0x890 kernel/kthread.c:463 ret_from_fork+0x4b8/0x860 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6285: 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] __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5763 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_chan_create+0x50/0x760 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1906 [inline] l2cap_sock_new_connection_cb+0x182/0x2b0 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x37a/0x1040 net/bluetooth/l2cap_core.c:7287 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2107 le_conn_complete_evt+0xfb8/0x1500 net/bluetooth/hci_event.c:5792 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5818 hci_event_func net/bluetooth/hci_event.c:7563 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7620 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4099 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x1790 kernel/workqueue.c:3346 worker_thread+0xa57/0xfc0 kernel/workqueue.c:3427 kthread+0x711/0x890 kernel/kthread.c:463 ret_from_fork+0x4b8/0x860 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 9935: 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:2539 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x19a/0x6d0 mm/slub.c:6837 l2cap_sock_cleanup_listen+0xea/0x3e0 net/bluetooth/l2cap_sock.c:1468 l2cap_sock_release+0x6a/0x210 net/bluetooth/l2cap_sock.c:1426 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x44c/0xa70 fs/file_table.c:468 fput_close_sync+0x119/0x200 fs/file_table.c:573 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8a/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e The buggy address belongs to the object at ffff888030475000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff888030475000, ffff888030475800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30470 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 ffff88813fe27000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe27000 dead000000000122 0000000000000000 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000c11c01 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 5883, tgid 5883 (kworker/1:3), ts 505853865325, free_ts 493364611427 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x2cf4/0x2ea0 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3055 [inline] allocate_slab+0x96/0x340 mm/slub.c:3228 new_slab mm/slub.c:3282 [inline] ___slab_alloc+0xecf/0x18d0 mm/slub.c:4651 __slab_alloc+0x65/0x100 mm/slub.c:4770 __slab_alloc_node mm/slub.c:4846 [inline] slab_alloc_node mm/slub.c:5268 [inline] __do_kmalloc_node mm/slub.c:5641 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5751 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] mld_newpack+0x13c/0xc30 net/ipv6/mcast.c:1775 add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1886 add_grec+0x13f9/0x16e0 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:3263 [inline] process_scheduled_works+0xae1/0x1790 kernel/workqueue.c:3346 worker_thread+0xa57/0xfc0 kernel/workqueue.c:3427 page last free pid 9696 tgid 9696 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc2/0xd30 mm/page_alloc.c:2906 discard_slab mm/slub.c:3326 [inline] __put_partials+0x144/0x160 mm/slub.c:3872 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3947 __slab_free+0x2b9/0x390 mm/slub.c:5921 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 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:4970 [inline] slab_alloc_node mm/slub.c:5280 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5332 alloc_task_struct_node kernel/fork.c:184 [inline] dup_task_struct+0x52/0x830 kernel/fork.c:873 copy_process+0x54b/0x3bf0 kernel/fork.c:2012 kernel_clone+0x21e/0x840 kernel/fork.c:2609 __do_sys_clone kernel/fork.c:2750 [inline] __se_sys_clone kernel/fork.c:2734 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8a/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e Memory state around the buggy address: ffff888030475380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888030475400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888030475480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888030475500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888030475580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================