==================================================================
BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x221/0x240 net/bluetooth/l2cap_sock.c:1500
Read of size 8 at addr ffff888021b555a8 by task kworker/u9:9/5860
CPU: 0 UID: 0 PID: 5860 Comm: kworker/u9:9 Tainted: G L syzkaller #0 PREEMPT(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:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
l2cap_sock_new_connection_cb+0x221/0x240 net/bluetooth/l2cap_sock.c:1500
l2cap_connect_cfm+0x4c7/0xfa0 net/bluetooth/l2cap_core.c:7288
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1968/0x1f20 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0xeb0 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Allocated by task 5860:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:262 [inline]
__do_kmalloc_node mm/slub.c:5652 [inline]
__kmalloc_noprof+0x32f/0x8f0 mm/slub.c:5664
kmalloc_noprof include/linux/slab.h:961 [inline]
sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2245
sk_alloc+0x36/0xc20 net/core/sock.c:2301
bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151
l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1897
l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1485
l2cap_connect_cfm+0x4c7/0xfa0 net/bluetooth/l2cap_core.c:7288
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1968/0x1f20 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0xeb0 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Freed by task 8718:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/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:6663 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6871
sk_prot_free net/core/sock.c:2284 [inline]
__sk_destruct+0x73f/0x910 net/core/sock.c:2384
sk_destruct+0xc2/0xf0 net/core/sock.c:2412
__sk_free+0xf4/0x3e0 net/core/sock.c:2423
sk_free+0x6a/0x90 net/core/sock.c:2434
sock_put include/net/sock.h:1998 [inline]
l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline]
l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1250
l2cap_sock_cleanup_listen+0x3d/0x2a0 net/bluetooth/l2cap_sock.c:1465
l2cap_sock_release+0x69/0x250 net/bluetooth/l2cap_sock.c:1426
__sock_release+0xb3/0x270 net/socket.c:653
sock_close+0x1c/0x30 net/socket.c:1446
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 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+0xfb/0x540 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+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888021b55000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1448 bytes inside of
freed 2048-byte region [ffff888021b55000, ffff888021b55800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21b50
head: order:3 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 ffff88813ff27000 ffffea0000a60e00 dead000000000002
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff27000 ffffea0000a60e00 dead000000000002
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea000086d401 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 9, tgid 9 (kworker/0:0), ts 15029173031, free_ts 0
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845
prep_new_page mm/page_alloc.c:1853 [inline]
get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3879
__alloc_frozen_pages_noprof+0x25f/0x2440 mm/page_alloc.c:5183
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab mm/slub.c:3248 [inline]
new_slab+0x2c3/0x430 mm/slub.c:3302
___slab_alloc+0xe18/0x1c90 mm/slub.c:4651
__slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4774
__slab_alloc_node mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:5246 [inline]
__kmalloc_cache_noprof+0x477/0x800 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
acpi_ds_create_walk_state+0x95/0x300 drivers/acpi/acpica/dswstate.c:518
acpi_ps_execute_method+0x2c1/0xe90 drivers/acpi/acpica/psxface.c:134
acpi_ns_evaluate+0x98c/0x16d0 drivers/acpi/acpica/nseval.c:205
acpi_ut_evaluate_object+0xf7/0x610 drivers/acpi/acpica/uteval.c:60
acpi_rs_get_method_data+0xa1/0x160 drivers/acpi/acpica/rsutils.c:650
acpi_walk_resources+0x178/0x270 drivers/acpi/acpica/rsxface.c:616
acpi_pci_link_get_current+0x1ce/0x3e0 drivers/acpi/pci_link.c:256
acpi_pci_link_set+0x593/0xa60 drivers/acpi/pci_link.c:362
page_owner free stack trace missing
Memory state around the buggy address:
ffff888021b55480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888021b55500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888021b55580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888021b55600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888021b55680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x4e9/0xfa0 net/bluetooth/l2cap_core.c:7290
Write of size 6 at addr ffff88802983c018 by task kworker/u9:9/5860
CPU: 0 UID: 0 PID: 5860 Comm: kworker/u9:9 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 10/25/2025
Workqueue: hci2 hci_rx_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:194 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200
__asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106
l2cap_connect_cfm+0x4e9/0xfa0 net/bluetooth/l2cap_core.c:7290
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1968/0x1f20 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0xeb0 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Allocated by task 5860:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
l2cap_chan_create+0x44/0x920 net/bluetooth/l2cap_core.c:445
l2cap_sock_alloc.constprop.0+0xf5/0x1d0 net/bluetooth/l2cap_sock.c:1906
l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1485
l2cap_connect_cfm+0x4c7/0xfa0 net/bluetooth/l2cap_core.c:7288
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1968/0x1f20 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0xeb0 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Freed by task 8718:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/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:6663 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6871
l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline]
kref_put include/linux/kref.h:65 [inline]
l2cap_chan_put+0x216/0x2c0 net/bluetooth/l2cap_core.c:516
l2cap_sock_cleanup_listen+0x4d/0x2a0 net/bluetooth/l2cap_sock.c:1468
l2cap_sock_release+0x69/0x250 net/bluetooth/l2cap_sock.c:1426
__sock_release+0xb3/0x270 net/socket.c:653
sock_close+0x1c/0x30 net/socket.c:1446
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 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+0xfb/0x540 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+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802983c000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 24 bytes inside of
freed 2048-byte region [ffff88802983c000, ffff88802983c800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29838
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ff27000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff27000 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000a60e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 20286786807, free_ts 0
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845
prep_new_page mm/page_alloc.c:1853 [inline]
get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3879
__alloc_frozen_pages_noprof+0x25f/0x2440 mm/page_alloc.c:5183
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab mm/slub.c:3248 [inline]
new_slab+0x2c3/0x430 mm/slub.c:3302
___slab_alloc+0xe18/0x1c90 mm/slub.c:4651
__slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4774
__slab_alloc_node mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:5246 [inline]
__kmalloc_cache_noprof+0x477/0x800 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
device_create_groups_vargs+0x8a/0x270 drivers/base/core.c:4353
device_create+0xed/0x130 drivers/base/core.c:4410
mon_bin_add+0xba/0x160 drivers/usb/mon/mon_bin.c:1372
mon_bus_init+0x18e/0x320 drivers/usb/mon/mon_main.c:291
mon_bus_add drivers/usb/mon/mon_main.c:188 [inline]
mon_notify+0x31c/0x480 drivers/usb/mon/mon_main.c:219
notifier_call_chain+0xbc/0x3e0 kernel/notifier.c:85
blocking_notifier_call_chain kernel/notifier.c:380 [inline]
blocking_notifier_call_chain+0x69/0xa0 kernel/notifier.c:368
usb_register_bus drivers/usb/core/hcd.c:908 [inline]
usb_add_hcd+0x498/0x1730 drivers/usb/core/hcd.c:2882
page_owner free stack trace missing
Memory state around the buggy address:
ffff88802983bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88802983bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802983c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802983c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802983c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================