================================================================== BUG: KASAN: slab-use-after-free in cfusbl_device_notify+0x16b/0x6b0 net/caif/caif_usb.c:142 Read of size 8 at addr ffff88803ba98d48 by task syz.2.4451/22104 CPU: 0 UID: 0 PID: 22104 Comm: syz.2.4451 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 cfusbl_device_notify+0x16b/0x6b0 net/caif/caif_usb.c:142 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2281 [inline] call_netdevice_notifiers net/core/dev.c:2295 [inline] register_netdevice+0x1248/0x1cd0 net/core/dev.c:11401 register_netdev+0x40/0x60 net/core/dev.c:11522 bnep_add_connection+0x6e5/0xca0 net/bluetooth/bnep/core.c:624 do_bnep_sock_ioctl+0x40b/0x650 net/bluetooth/bnep/sock.c:83 sock_do_ioctl+0x101/0x320 net/socket.c:1254 sock_ioctl+0x5c6/0x7f0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe9fe99aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe9ff781028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe9fec16090 RCX: 00007fe9fe99aeb9 RDX: 0000200000000080 RSI: 00000000400442c8 RDI: 0000000000000005 RBP: 00007fe9fea08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe9fec16128 R14: 00007fe9fec16090 R15: 00007ffdd260c208 Allocated by task 5835: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] __hci_conn_add+0x3c5/0x1b30 net/bluetooth/hci_conn.c:963 hci_conn_request_evt+0x5b1/0xc40 net/bluetooth/hci_event.c:3299 hci_event_func net/bluetooth/hci_event.c:7719 [inline] hci_event_packet+0x805/0x12c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4076 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 22089: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x1be/0x650 mm/slub.c:6882 device_release+0x9e/0x1d0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x560 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline] hci_conn_del+0xc36/0x1230 net/bluetooth/hci_conn.c:1234 hci_conn_hash_flush+0x191/0x260 net/bluetooth/hci_conn.c:2638 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5327 hci_dev_do_close+0x30/0xc0 net/bluetooth/hci_core.c:501 hci_rfkill_set_block+0x1f4/0x290 net/bluetooth/hci_core.c:929 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346 rfkill_fop_write+0x461/0x5a0 net/rfkill/core.c:1301 vfs_write+0x29a/0xb90 fs/read_write.c:684 ksys_write+0x150/0x270 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2180 __queue_work+0xccf/0xf90 kernel/workqueue.c:2335 queue_delayed_work_on+0x11a/0x1e0 kernel/workqueue.c:2555 l2cap_chan_del+0x285/0x610 net/bluetooth/l2cap_core.c:672 l2cap_conn_del+0x326/0x5b0 net/bluetooth/l2cap_core.c:1788 hci_disconn_cfm include/net/bluetooth/hci_core.h:2146 [inline] hci_conn_hash_flush+0x10d/0x260 net/bluetooth/hci_conn.c:2637 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5327 hci_dev_do_close+0x30/0xc0 net/bluetooth/hci_core.c:501 hci_rfkill_set_block+0x1f4/0x290 net/bluetooth/hci_core.c:929 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346 rfkill_fop_write+0x461/0x5a0 net/rfkill/core.c:1301 vfs_write+0x29a/0xb90 fs/read_write.c:684 ksys_write+0x150/0x270 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803ba98000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 3400 bytes inside of freed 8192-byte region [ffff88803ba98000, ffff88803ba9a000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3ba98 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 ffff88813fe27280 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe27280 dead000000000122 0000000000000000 head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000eea601 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 5835, tgid 5835 (kworker/u9:4), ts 360337494360, free_ts 360169984144 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3a0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xd82/0x1760 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x40d/0x6e0 mm/slub.c:5775 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] __hci_conn_add+0x3c5/0x1b30 net/bluetooth/hci_conn.c:963 hci_conn_request_evt+0x5b1/0xc40 net/bluetooth/hci_event.c:3299 hci_event_func net/bluetooth/hci_event.c:7719 [inline] hci_event_packet+0x805/0x12c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4076 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 page last free pid 18225 tgid 18224 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xbf8/0xd70 mm/page_alloc.c:2973 __folio_put+0x414/0x4f0 mm/swap.c:112 folio_put include/linux/mm.h:1616 [inline] put_page include/linux/mm.h:1685 [inline] do_exit+0x1843/0x2310 kernel/exit.c:1002 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x86/0x480 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 Memory state around the buggy address: ffff88803ba98c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803ba98c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803ba98d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803ba98d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803ba98e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================