================================================================== BUG: KASAN: slab-use-after-free in cfusbl_device_notify+0x883/0x900 net/caif/caif_usb.c:142 Read of size 8 at addr ffff888037558c50 by task syz.6.2891/16737 CPU: 1 UID: 0 PID: 16737 Comm: syz.6.2891 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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/0x610 mm/kasan/report.c:480 kasan_report+0xe0/0x110 mm/kasan/report.c:593 cfusbl_device_notify+0x883/0x900 net/caif/caif_usb.c:142 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] register_netdevice+0xe02/0x2270 net/core/dev.c:11100 register_netdev+0x34/0x50 net/core/dev.c:11221 bnep_add_connection+0x71c/0xd20 net/bluetooth/bnep/core.c:624 do_bnep_sock_ioctl.constprop.0+0x496/0x590 net/bluetooth/bnep/sock.c:83 sock_do_ioctl+0x118/0x280 net/socket.c:1190 sock_ioctl+0x227/0x6b0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faef658e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007faef734b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007faef67b5fa0 RCX: 00007faef658e929 RDX: 0000200000000540 RSI: 00000000400442c8 RDI: 0000000000000008 RBP: 00007faef6610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faef67b5fa0 R15: 00007ffcff1a3e68 Allocated by task 5839: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] __hci_conn_add+0x130/0x1b70 net/bluetooth/hci_conn.c:939 hci_conn_add_unset+0x6d/0x100 net/bluetooth/hci_conn.c:1051 hci_conn_request_evt+0x88a/0xaf0 net/bluetooth/hci_event.c:3282 hci_event_func net/bluetooth/hci_event.c:7478 [inline] hci_event_packet+0xa10/0x11c0 net/bluetooth/hci_event.c:7532 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4070 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 10757: 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:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 device_release+0xa1/0x240 drivers/base/core.c:2568 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e7/0x5a0 lib/kobject.c:737 put_device drivers/base/core.c:3800 [inline] device_unregister+0x2f/0xc0 drivers/base/core.c:3923 hci_conn_del_sysfs+0xb4/0x180 net/bluetooth/hci_sysfs.c:79 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline] hci_conn_del+0x566/0xdc0 net/bluetooth/hci_conn.c:1173 hci_abort_conn_sync+0x762/0xb10 net/bluetooth/hci_sync.c:5689 abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:2885 hci_cmd_sync_work+0x1a8/0x430 net/bluetooth/hci_sync.c:332 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548 insert_work+0x36/0x230 kernel/workqueue.c:2183 __queue_work+0x97e/0x10f0 kernel/workqueue.c:2341 __queue_delayed_work+0x35b/0x460 kernel/workqueue.c:2509 queue_delayed_work_on+0x1b5/0x200 kernel/workqueue.c:2561 queue_delayed_work include/linux/workqueue.h:677 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1661 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1635 [inline] l2cap_chan_del+0x5a0/0x8f0 net/bluetooth/l2cap_core.c:671 l2cap_conn_del+0x37a/0x730 net/bluetooth/l2cap_core.c:1787 l2cap_connect_cfm+0x9e1/0xf80 net/bluetooth/l2cap_core.c:7243 hci_connect_cfm include/net/bluetooth/hci_core.h:2055 [inline] hci_conn_failed+0x1ba/0x330 net/bluetooth/hci_conn.c:1275 hci_abort_conn_sync+0x762/0xb10 net/bluetooth/hci_sync.c:5689 abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:2885 hci_cmd_sync_work+0x1a8/0x430 net/bluetooth/hci_sync.c:332 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888037558000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 3152 bytes inside of freed 8192-byte region [ffff888037558000, ffff88803755a000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x37558 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 ffff88801b842280 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842280 dead000000000122 0000000000000000 head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000dd5601 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 5839, tgid 5839 (kworker/u9:6), ts 679753708451, free_ts 679729149399 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] __hci_conn_add+0x130/0x1b70 net/bluetooth/hci_conn.c:939 hci_conn_add_unset+0x6d/0x100 net/bluetooth/hci_conn.c:1051 hci_conn_request_evt+0x88a/0xaf0 net/bluetooth/hci_event.c:3282 hci_event_func net/bluetooth/hci_event.c:7478 [inline] hci_event_packet+0xa10/0x11c0 net/bluetooth/hci_event.c:7532 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4070 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 page last free pid 1635 tgid 1635 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 __folio_put+0x329/0x450 mm/swap.c:112 unix_net_exit+0x61/0xb0 net/unix/af_unix.c:3790 ops_exit_list net/core/net_namespace.c:200 [inline] ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:253 cleanup_net+0x408/0x890 net/core/net_namespace.c:686 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888037558b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888037558b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888037558c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888037558c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888037558d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================