================================================================== 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+0x812/0x1300 kernel/locking/mutex.c:776 Read of size 8 at addr ffff888033b1c0a8 by task khidpd_00065508/6143 CPU: 0 UID: 0 PID: 6143 Comm: khidpd_00065508 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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 __mutex_waiter_is_first kernel/locking/mutex.c:199 [inline] __mutex_lock_common kernel/locking/mutex.c:694 [inline] __mutex_lock+0x812/0x1300 kernel/locking/mutex.c:776 l2cap_unregister_user+0x6a/0x1b0 net/bluetooth/l2cap_core.c:1721 hidp_session_thread+0x3cb/0x440 net/bluetooth/hidp/core.c:1304 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 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33b1c head: order:2 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 ffff88801eabcdc0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000800130013 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801eabcdc0 dead000000000122 0000000000000000 head: 0000000000000000 0000000800130013 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000cec701 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xf2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_MEMALLOC|__GFP_COMP|__GFP_NOMEMALLOC), pid 7570, tgid 7555 (syz.5.463), ts 214130601928, free_ts 214101867779 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+0x24dc/0x2580 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+0x331/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4918 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713 __netdev_alloc_skb+0xc1/0x810 net/core/skbuff.c:775 netdev_alloc_skb include/linux/skbuff.h:3485 [inline] dev_alloc_skb include/linux/skbuff.h:3498 [inline] __ieee80211_beacon_get+0xc06/0x1880 net/mac80211/tx.c:5656 ieee80211_beacon_get_tim+0xbd/0x2c0 net/mac80211/tx.c:5778 ieee80211_beacon_get include/net/mac80211.h:5720 [inline] mac80211_hwsim_beacon_tx+0x3c5/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2361 __iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:760 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:796 mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849 page last free pid 6976 tgid 6976 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 bt_host_release+0x82/0x90 net/bluetooth/hci_sysfs.c:87 device_release+0x9e/0x1d0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x560 lib/kobject.c:737 vhci_release+0x15a/0x1a0 drivers/bluetooth/hci_vhci.c:691 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x23c0 kernel/exit.c:976 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x1284/0x1330 kernel/signal.c:3034 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 Memory state around the buggy address: ffff888033b1bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888033b1c000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888033b1c080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888033b1c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888033b1c180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================