=========[  337.509070][ T5800] ==================================================================
BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1500
Read of size 8 at addr ffff8880282bf7b0 by task kworker/u9:2/5800

CPU: 1 UID: 0 PID: 5800 Comm: kworker/u9:2 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci2 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 l2cap_sock_new_connection_cb+0x1f9/0x2e0 net/bluetooth/l2cap_sock.c:1500
 l2cap_connect_cfm+0x367/0x10e0 net/bluetooth/l2cap_core.c:7288
 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2131
 le_conn_complete_evt+0xf65/0x1420 net/bluetooth/hci_event.c:5821
 hci_le_conn_complete_evt+0x187/0x480 net/bluetooth/hci_event.c:5847
 hci_event_func net/bluetooth/hci_event.c:7716 [inline]
 hci_event_packet+0x78f/0x1260 net/bluetooth/hci_event.c:7773
 hci_rx_work+0x3ee/0x1060 net/bluetooth/hci_core.c:4076
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 5800:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5657 [inline]
 __kmalloc_noprof+0x23e/0x7e0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 sk_prot_alloc+0xe7/0x220 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:1897 [inline]
 l2cap_sock_new_connection_cb+0xe2/0x2e0 net/bluetooth/l2cap_sock.c:1485
 l2cap_connect_cfm+0x367/0x10e0 net/bluetooth/l2cap_core.c:7288
 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2131
 le_conn_complete_evt+0xf65/0x1420 net/bluetooth/hci_event.c:5821
 hci_le_conn_complete_evt+0x187/0x480 net/bluetooth/hci_event.c:5847
 hci_event_func net/bluetooth/hci_event.c:7716 [inline]
 hci_event_packet+0x78f/0x1260 net/bluetooth/hci_event.c:7773
 hci_rx_work+0x3ee/0x1060 net/bluetooth/hci_core.c:4076
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Freed by task 7980:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6670 [inline]
 kfree+0x1bd/0x900 mm/slub.c:6878
 sk_prot_free net/core/sock.c:2284 [inline]
 __sk_destruct+0x626/0x880 net/core/sock.c:2384
 l2cap_sock_cleanup_listen+0xe0/0x450 net/bluetooth/l2cap_sock.c:1465
 l2cap_sock_release+0x6e/0x270 net/bluetooth/l2cap_sock.c:1426
 __sock_release net/socket.c:662 [inline]
 sock_close+0xc3/0x240 net/socket.c:1455
 __fput+0x45b/0xa80 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xef/0x4e0 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+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880282bf000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1968 bytes inside of
 freed 2048-byte region [ffff8880282bf000, ffff8880282bf800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x282b8
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 ffff88813ff27000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813ff27000 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0080000000000003 ffffea0000a0ae01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 22109109535, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xb10/0x13e0 mm/slub.c:4656
 __slab_alloc+0xc6/0x1f0 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __kmalloc_cache_noprof+0x101/0x6d0 mm/slub.c:5771
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 device_create_groups_vargs drivers/base/core.c:4353 [inline]
 device_create+0x12f/0x2f0 drivers/base/core.c:4410
 mon_bin_add+0xb6/0x130 drivers/usb/mon/mon_bin.c:1372
 mon_bus_init+0x173/0x2b0 drivers/usb/mon/mon_main.c:291
 mon_bus_add drivers/usb/mon/mon_main.c:188 [inline]
 mon_notify+0x112/0x400 drivers/usb/mon/mon_main.c:219
 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
 usb_register_bus+0xcf/0x150 drivers/usb/core/hcd.c:908
 usb_add_hcd+0x451/0x10b0 drivers/usb/core/hcd.c:2882
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880282bf680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880282bf700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880282bf780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880282bf800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880282bf880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================