==================================================================
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 ffff8880a69980a8 by task khidpd_15c25886/24255

CPU: 0 UID: 0 PID: 24255 Comm: khidpd_15c25886 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 __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
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880a699ba80 pfn:0xa6998
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00022b5408 ffff8880b84410c0 0000000000000000
raw: ffff8880a699ba80 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 23592, tgid 23592 (syz-executor), ts 1190559090279, free_ts 1346971606581
 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
 ___kmalloc_large_node+0x104/0x150 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kmalloc_noprof+0x6b1/0x9c0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 hci_alloc_dev_priv+0x1d/0x28a0 net/bluetooth/hci_core.c:2448
 hci_alloc_dev include/net/bluetooth/hci_core.h:1761 [inline]
 __vhci_create_device+0xf0/0x880 drivers/bluetooth/hci_vhci.c:421
 vhci_create_device drivers/bluetooth/hci_vhci.c:479 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline]
 vhci_write+0x2c4/0x490 drivers/bluetooth/hci_vhci.c:616
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 24725 tgid 24725 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:
 ffff8880a6997f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880a6998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                  ^
 ffff8880a6998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6998180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
==================================================================
BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x23b/0x260 kernel/locking/spinlock_debug.c:115
Read of size 4 at addr ffff8880a6998064 by task khidpd_15c25886/24255

CPU: 0 UID: 0 PID: 24255 Comm: khidpd_15c25886 Tainted: G    B        L      syzkaller #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 __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
 debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
 do_raw_spin_lock+0x23b/0x260 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162
 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
 set_task_blocked_on include/linux/sched.h:2164 [inline]
 __mutex_lock_common kernel/locking/mutex.c:701 [inline]
 __mutex_lock+0xcc7/0x1b90 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
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880a699ba80 pfn:0xa6998
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00022b5408 ffff8880b84410c0 0000000000000000
raw: ffff8880a699ba80 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 23592, tgid 23592 (syz-executor), ts 1190559090279, free_ts 1346971606581
 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
 ___kmalloc_large_node+0x104/0x150 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kmalloc_noprof+0x6b1/0x9c0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 hci_alloc_dev_priv+0x1d/0x28a0 net/bluetooth/hci_core.c:2448
 hci_alloc_dev include/net/bluetooth/hci_core.h:1761 [inline]
 __vhci_create_device+0xf0/0x880 drivers/bluetooth/hci_vhci.c:421
 vhci_create_device drivers/bluetooth/hci_vhci.c:479 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline]
 vhci_write+0x2c4/0x490 drivers/bluetooth/hci_vhci.c:616
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 24725 tgid 24725 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:
 ffff8880a6997f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6997f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880a6998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                       ^
 ffff8880a6998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
==================================================================
BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:87 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x248/0x260 kernel/locking/spinlock_debug.c:115
Read of size 8 at addr ffff8880a6998070 by task khidpd_15c25886/24255

CPU: 0 UID: 0 PID: 24255 Comm: khidpd_15c25886 Tainted: G    B        L      syzkaller #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 __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
 debug_spin_lock_before kernel/locking/spinlock_debug.c:87 [inline]
 do_raw_spin_lock+0x248/0x260 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162
 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
 set_task_blocked_on include/linux/sched.h:2164 [inline]
 __mutex_lock_common kernel/locking/mutex.c:701 [inline]
 __mutex_lock+0xcc7/0x1b90 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
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880a699ba80 pfn:0xa6998
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00022b5408 ffff8880b84410c0 0000000000000000
raw: ffff8880a699ba80 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 23592, tgid 23592 (syz-executor), ts 1190559090279, free_ts 1346971606581
 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
 ___kmalloc_large_node+0x104/0x150 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kmalloc_noprof+0x6b1/0x9c0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 hci_alloc_dev_priv+0x1d/0x28a0 net/bluetooth/hci_core.c:2448
 hci_alloc_dev include/net/bluetooth/hci_core.h:1761 [inline]
 __vhci_create_device+0xf0/0x880 drivers/bluetooth/hci_vhci.c:421
 vhci_create_device drivers/bluetooth/hci_vhci.c:479 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline]
 vhci_write+0x2c4/0x490 drivers/bluetooth/hci_vhci.c:616
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 24725 tgid 24725 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:
 ffff8880a6997f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6997f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880a6998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                             ^
 ffff8880a6998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
==================================================================
BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:88 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x231/0x260 kernel/locking/spinlock_debug.c:115
Read of size 4 at addr ffff8880a6998068 by task khidpd_15c25886/24255

CPU: 0 UID: 0 PID: 24255 Comm: khidpd_15c25886 Tainted: G    B        L      syzkaller #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 __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
 debug_spin_lock_before kernel/locking/spinlock_debug.c:88 [inline]
 do_raw_spin_lock+0x231/0x260 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162
 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
 set_task_blocked_on include/linux/sched.h:2164 [inline]
 __mutex_lock_common kernel/locking/mutex.c:701 [inline]
 __mutex_lock+0xcc7/0x1b90 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
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880a699ba80 pfn:0xa6998
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00022b5408 ffff8880b84410c0 0000000000000000
raw: ffff8880a699ba80 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 23592, tgid 23592 (syz-executor), ts 1190559090279, free_ts 1346971606581
 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
 ___kmalloc_large_node+0x104/0x150 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kmalloc_noprof+0x6b1/0x9c0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 hci_alloc_dev_priv+0x1d/0x28a0 net/bluetooth/hci_core.c:2448
 hci_alloc_dev include/net/bluetooth/hci_core.h:1761 [inline]
 __vhci_create_device+0xf0/0x880 drivers/bluetooth/hci_vhci.c:421
 vhci_create_device drivers/bluetooth/hci_vhci.c:479 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline]
 vhci_write+0x2c4/0x490 drivers/bluetooth/hci_vhci.c:616
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 24725 tgid 24725 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:
 ffff8880a6997f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6997f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880a6998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff8880a6998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: use-after-free in atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline]
BUG: KASAN: use-after-free in queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x119/0x260 kernel/locking/spinlock_debug.c:116
Write of size 4 at addr ffff8880a6998060 by task khidpd_15c25886/24255

CPU: 0 UID: 0 PID: 24255 Comm: khidpd_15c25886 Tainted: G    B        L      syzkaller #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 __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
 check_region_inline mm/kasan/generic.c:186 [inline]
 kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock+0x119/0x260 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162
 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
 set_task_blocked_on include/linux/sched.h:2164 [inline]
 __mutex_lock_common kernel/locking/mutex.c:701 [inline]
 __mutex_lock+0xcc7/0x1b90 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
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880a699ba80 pfn:0xa6998
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00022b5408 ffff8880b84410c0 0000000000000000
raw: ffff8880a699ba80 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 23592, tgid 23592 (syz-executor), ts 1190559090279, free_ts 1346971606581
 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
 ___kmalloc_large_node+0x104/0x150 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kmalloc_noprof+0x6b1/0x9c0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 hci_alloc_dev_priv+0x1d/0x28a0 net/bluetooth/hci_core.c:2448
 hci_alloc_dev include/net/bluetooth/hci_core.h:1761 [inline]
 __vhci_create_device+0xf0/0x880 drivers/bluetooth/hci_vhci.c:421
 vhci_create_device drivers/bluetooth/hci_vhci.c:479 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline]
 vhci_write+0x2c4/0x490 drivers/bluetooth/hci_vhci.c:616
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 24725 tgid 24725 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:
 ffff8880a6997f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6997f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880a6998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                       ^
 ffff8880a6998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880a6998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================