Bluetooth: hci1: unexpected cc 0x0c23 length: 249 > 4 Bluetooth: hci1: unexpected cc 0x0c38 length: 249 > 2 ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x22a/0x240 net/bluetooth/l2cap_sock.c:1500 Read of size 8 at addr ffff8881432bc590 by task kworker/u9:2/15866 CPU: 1 UID: 0 PID: 15866 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: hci1 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+0x22a/0x240 net/bluetooth/l2cap_sock.c:1500 l2cap_connect_cfm+0x4c7/0xf80 net/bluetooth/l2cap_core.c:7287 hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234 hci_event_func net/bluetooth/hci_event.c:7542 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 15866: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4376 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2239 sk_alloc+0x36/0xc20 net/core/sock.c:2295 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+0x4c7/0xf80 net/bluetooth/l2cap_core.c:7287 hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234 hci_event_func net/bluetooth/hci_event.c:7542 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 16855: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4894 sk_prot_free net/core/sock.c:2278 [inline] __sk_destruct+0x75f/0x9a0 net/core/sock.c:2373 sk_destruct+0xc2/0xf0 net/core/sock.c:2401 __sk_free+0xf4/0x3e0 net/core/sock.c:2412 sk_free+0x6a/0x90 net/core/sock.c:2423 sock_put include/net/sock.h:1962 [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:649 sock_close+0x1c/0x30 net/socket.c:1439 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x41c/0x4e0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8881432bc000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1424 bytes inside of freed 2048-byte region [ffff8881432bc000, ffff8881432bc800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1432b8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 057ff00000000040 ffff88801b842000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 057ff00000000040 ffff88801b842000 dead000000000100 dead000000000122 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 057ff00000000003 ffffea00050cae01 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 2199252500, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] acpi_ds_build_internal_package_obj+0x906/0xcf0 drivers/acpi/acpica/dspkginit.c:112 acpi_ds_eval_data_object_operands+0x322/0x540 drivers/acpi/acpica/dsopcode.c:638 acpi_ds_exec_end_op+0xde1/0x1460 drivers/acpi/acpica/dswexec.c:607 acpi_ps_parse_loop+0x428/0x1d00 drivers/acpi/acpica/psloop.c:525 acpi_ps_parse_aml+0x3c1/0xcb0 drivers/acpi/acpica/psparse.c:475 acpi_ps_execute_table+0x37b/0x4d0 drivers/acpi/acpica/psxface.c:295 acpi_ns_execute_table+0x3e2/0x5b0 drivers/acpi/acpica/nsparse.c:116 acpi_ns_load_table+0x5b/0x130 drivers/acpi/acpica/nsload.c:71 page_owner free stack trace missing Memory state around the buggy address: ffff8881432bc480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881432bc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881432bc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881432bc600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881432bc680: 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+0x4e9/0xf80 net/bluetooth/l2cap_core.c:7289 Write of size 6 at addr ffff8881432b9018 by task kworker/u9:2/15866 CPU: 1 UID: 0 PID: 15866 Comm: kworker/u9:2 Tainted: G B syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: hci1 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:183 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 l2cap_connect_cfm+0x4e9/0xf80 net/bluetooth/l2cap_core.c:7289 hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234 hci_event_func net/bluetooth/hci_event.c:7542 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 15866: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [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+0x4c7/0xf80 net/bluetooth/l2cap_core.c:7287 hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234 hci_event_func net/bluetooth/hci_event.c:7542 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 16855: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4894 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:515 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:649 sock_close+0x1c/0x30 net/socket.c:1439 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x41c/0x4e0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8881432b9000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 24 bytes inside of freed 2048-byte region [ffff8881432b9000, ffff8881432b9800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1432b8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 057ff00000000040 ffff88801b842000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 057ff00000000040 ffff88801b842000 dead000000000100 dead000000000122 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 057ff00000000003 ffffea00050cae01 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 2199252500, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] acpi_ds_build_internal_package_obj+0x906/0xcf0 drivers/acpi/acpica/dspkginit.c:112 acpi_ds_eval_data_object_operands+0x322/0x540 drivers/acpi/acpica/dsopcode.c:638 acpi_ds_exec_end_op+0xde1/0x1460 drivers/acpi/acpica/dswexec.c:607 acpi_ps_parse_loop+0x428/0x1d00 drivers/acpi/acpica/psloop.c:525 acpi_ps_parse_aml+0x3c1/0xcb0 drivers/acpi/acpica/psparse.c:475 acpi_ps_execute_table+0x37b/0x4d0 drivers/acpi/acpica/psxface.c:295 acpi_ns_execute_table+0x3e2/0x5b0 drivers/acpi/acpica/nsparse.c:116 acpi_ns_load_table+0x5b/0x130 drivers/acpi/acpica/nsload.c:71 page_owner free stack trace missing Memory state around the buggy address: ffff8881432b8f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881432b8f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881432b9000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881432b9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881432b9100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================