ret_from_fork+0x51e/0xb90 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 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+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1525 Read of size 8 at addr ffff88806ffb07b0 by task kworker/u9:0/17517 CPU: 0 UID: 0 PID: 17517 Comm: kworker/u9:0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: hci0 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 l2cap_sock_new_connection_cb+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1525 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5884 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 17517: 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:5260 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2245 sk_alloc+0x3a/0x390 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1925 [inline] l2cap_sock_new_connection_cb+0xe2/0x2e0 net/bluetooth/l2cap_sock.c:1510 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5884 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 18993: 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:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1c1/0x6c0 mm/slub.c:6483 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x626/0x880 net/core/sock.c:2384 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 net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x461/0xa90 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11c3/0x1310 kernel/signal.c:2807 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 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+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88806ffb0000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1968 bytes inside of freed 2048-byte region [ffff88806ffb0000, ffff88806ffb0800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6ffb0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe1a000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe1a000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 0080000000000003 ffffea0001bfec01 00000000ffffffff 00000000ffffffff head: 0000000000000e30 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 14907, tgid 14905 (syz.2.2721), ts 1014170249842, free_ts 975660202133 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x77/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x35c/0x710 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_node_track_caller_noprof+0x60b/0x7e0 mm/slub.c:5368 kmalloc_reserve net/core/skbuff.c:635 [inline] __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6763 sock_alloc_send_pskb+0x884/0x9a0 net/core/sock.c:2995 sock_alloc_send_skb include/net/sock.h:1894 [inline] llc_ui_sendmsg+0x487/0xea0 net/llc/af_llc.c:970 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_sendmsg+0x3fb/0x450 net/socket.c:765 splice_to_socket+0xae5/0x11f0 fs/splice.c:884 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x104/0x160 fs/splice.c:1159 splice_direct_to_actor+0x545/0xc80 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x19b/0x2a0 fs/splice.c:1228 page last free pid 5882 tgid 5882 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978 kasan_depopulate_vmalloc_pte+0x6d/0x90 mm/kasan/shadow.c:484 apply_to_pte_range mm/memory.c:3243 [inline] apply_to_pmd_range mm/memory.c:3287 [inline] apply_to_pud_range mm/memory.c:3323 [inline] apply_to_p4d_range mm/memory.c:3359 [inline] __apply_to_page_range+0xbdc/0x1420 mm/memory.c:3395 __kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:602 kasan_release_vmalloc include/linux/kasan.h:593 [inline] kasan_release_vmalloc_node mm/vmalloc.c:2290 [inline] purge_vmap_node+0x220/0x960 mm/vmalloc.c:2312 __purge_vmap_area_lazy+0x779/0xb70 mm/vmalloc.c:2402 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2436 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88806ffb0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806ffb0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806ffb0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806ffb0800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88806ffb0880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================