================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:199 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:694 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x1861/0x1b90 kernel/locking/mutex.c:776 Read of size 8 at addr ffff888065d200a8 by task khidpd_10000008/32689 CPU: 0 UID: 0 PID: 32689 Comm: khidpd_10000008 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 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 __mutex_waiter_is_first kernel/locking/mutex.c:199 [inline] __mutex_lock_common kernel/locking/mutex.c:694 [inline] __mutex_lock+0x1861/0x1b90 kernel/locking/mutex.c:776 l2cap_unregister_user+0x71/0x240 net/bluetooth/l2cap_core.c:1729 hidp_session_thread+0x459/0x680 net/bluetooth/hidp/core.c:1304 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888065d230c0 pfn:0x65d20 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0000d26e08 ffff8880b8540f80 0000000000000000 raw: ffff888065d230c0 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_ZERO|__GFP_COMP), pid 31502, tgid 31502 (syz-executor), ts 1567394831572, free_ts 1714034065097 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c4/0x440 mm/slub.c:3302 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] kmem_cache_alloc_node_noprof+0x51e/0x880 mm/slub.c:5315 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:586 __alloc_skb+0x186/0x410 net/core/skbuff.c:690 __netdev_alloc_skb+0x7a/0x8f0 net/core/skbuff.c:754 netdev_alloc_skb include/linux/skbuff.h:3484 [inline] dev_alloc_skb include/linux/skbuff.h:3497 [inline] __ieee80211_beacon_get+0xba1/0x1ee0 net/mac80211/tx.c:5656 ieee80211_beacon_get_tim+0xa6/0x280 net/mac80211/tx.c:5778 ieee80211_beacon_get include/net/mac80211.h:5669 [inline] mac80211_hwsim_beacon_tx+0x4d6/0xa00 drivers/net/wireless/virtual/mac80211_hwsim.c:2361 __iterate_interfaces+0x2e6/0x650 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0x71/0x1b0 net/mac80211/util.c:797 page last free pid 31502 tgid 31502 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973 hci_release_dev+0x4ef/0x630 net/bluetooth/hci_core.c:2776 bt_host_release+0x6a/0xb0 net/bluetooth/hci_sysfs.c:87 device_release+0xa4/0x240 drivers/base/core.c:2565 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1f7/0x640 lib/kobject.c:737 put_device+0x1f/0x30 drivers/base/core.c:3797 vhci_release+0x185/0x230 drivers/bluetooth/hci_vhci.c:691 __fput+0x3ff/0xb40 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x829/0x2a30 kernel/exit.c:971 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x86/0x4b0 kernel/entry/common.c:75 __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_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888065d1ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888065d20000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888065d20080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888065d20100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888065d20180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================