================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:174 Read of size 1 at addr ffff88805e521330 by task kworker/0:8/8360 CPU: 0 UID: 0 PID: 8360 Comm: kworker/0:8 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events l2cap_chan_timeout 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 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5844 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:174 rt_mutex_slowlock_block+0x510/0x680 kernel/locking/rtmutex.c:1665 __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1779 [inline] rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1819 __rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553 l2cap_chan_timeout+0x63/0x3b0 net/bluetooth/l2cap_core.c:417 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 15331: 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] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] l2cap_conn_add+0xaa/0x970 net/bluetooth/l2cap_core.c:7001 l2cap_chan_connect+0x6a8/0xed0 net/bluetooth/l2cap_core.c:7192 l2cap_sock_connect+0x5ea/0x7f0 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x141/0x1c0 net/socket.c:3758 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x61d/0x1210 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x2f7/0x640 net/bluetooth/rfcomm/sock.c:410 __sys_connect_file net/socket.c:2163 [inline] __sys_connect+0x315/0x450 net/socket.c:2182 __do_sys_connect net/socket.c:2188 [inline] __se_sys_connect net/socket.c:2185 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2185 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15136: 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 hci_disconn_cfm include/net/bluetooth/hci_core.h:2154 [inline] hci_conn_hash_flush+0x10d/0x260 net/bluetooth/hci_conn.c:2734 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5368 hci_dev_do_close net/bluetooth/hci_core.c:502 [inline] hci_unregister_dev+0x21a/0x5a0 net/bluetooth/hci_core.c:2716 vhci_release+0x155/0x1b0 drivers/bluetooth/hci_vhci.c:690 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 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: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 ffff88805e521000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 816 bytes inside of freed 1024-byte region [ffff88805e521000, ffff88805e521400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e520 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 ffff88813fe14dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe14dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5823, tgid 5823 (syz-executor), ts 82541688235, 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] __kmalloc_cache_noprof+0x44e/0x690 mm/slub.c:5410 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] batadv_hardif_add_interface net/batman-adv/hard-interface.c:874 [inline] batadv_hard_if_event+0xb21/0x1240 net/batman-adv/hard-interface.c:958 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] register_netdevice+0x18d5/0x1ed0 net/core/dev.c:11466 macvlan_common_newlink+0x12af/0x1a40 drivers/net/macvlan.c:1554 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3863 __rtnl_newlink net/core/rtnetlink.c:3994 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4109 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6995 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x780/0x920 net/netlink/af_netlink.c:1344 page_owner free stack trace missing Memory state around the buggy address: ffff88805e521200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e521280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805e521300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805e521380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e521400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================