==================================================================
BUG: KASAN: slab-use-after-free in cfusbl_device_notify+0x18a/0x6e0 net/caif/caif_usb.c:142
Read of size 8 at addr ffff88805898cc50 by task syz.4.1533/11606

CPU: 0 UID: 0 PID: 11606 Comm: syz.4.1533 Not tainted 6.15.0-rc2-syzkaller-00577-g8066e388be48 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 cfusbl_device_notify+0x18a/0x6e0 net/caif/caif_usb.c:142
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2266 [inline]
 call_netdevice_notifiers net/core/dev.c:2280 [inline]
 register_netdevice+0x1264/0x1b80 net/core/dev.c:11059
 register_netdev+0x40/0x50 net/core/dev.c:11180
 bnep_add_connection+0x865/0xe80 net/bluetooth/bnep/core.c:624
 do_bnep_sock_ioctl+0x526/0x920 net/bluetooth/bnep/sock.c:83
 sock_do_ioctl+0x152/0x400 net/socket.c:1190
 sock_ioctl+0x644/0x900 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c5378e169
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:00007f1c54523038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1c539b6080 RCX: 00007f1c5378e169
RDX: 0000200000000540 RSI: 00000000400442c8 RDI: 000000000000000f
RBP: 00007f1c53810a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1c539b6080 R15: 00007ffe3875e648
 </TASK>

Allocated by task 5840:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x9d/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x236/0x370 mm/slub.c:4372
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 __hci_conn_add+0x317/0x19c0 net/bluetooth/hci_conn.c:936
 hci_conn_request_evt+0x683/0xfa0 net/bluetooth/hci_event.c:3289
 hci_event_func net/bluetooth/hci_event.c:7493 [inline]
 hci_event_packet+0xac9/0x1550 net/bluetooth/hci_event.c:7545
 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4020
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 11261:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2398 [inline]
 slab_free mm/slub.c:4656 [inline]
 kfree+0x198/0x430 mm/slub.c:4855
 device_release+0x99/0x1c0 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+0x22f/0x480 lib/kobject.c:737
 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline]
 hci_conn_del+0x8d5/0xc50 net/bluetooth/hci_conn.c:1167
 hci_conn_hash_flush+0x18e/0x240 net/bluetooth/hci_conn.c:2702
 hci_dev_close_sync+0xa8d/0x1260 net/bluetooth/hci_sync.c:5225
 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline]
 hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2678
 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x3e9/0x9f0 fs/file_table.c:465
 task_work_run+0x251/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa11/0x27f0 kernel/exit.c:953
 do_group_exit+0x207/0x2c0 kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbf/0xd0 mm/kasan/generic.c:548
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xda3/0x10a0 kernel/workqueue.c:2341
 queue_delayed_work_on+0x1cc/0x390 kernel/workqueue.c:2561
 l2cap_chan_del+0x291/0x5d0 net/bluetooth/l2cap_core.c:671
 l2cap_conn_del+0x391/0x690 net/bluetooth/l2cap_core.c:1786
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline]
 hci_conn_hash_flush+0xff/0x240 net/bluetooth/hci_conn.c:2701
 hci_dev_close_sync+0xa8d/0x1260 net/bluetooth/hci_sync.c:5225
 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline]
 hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2678
 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x3e9/0x9f0 fs/file_table.c:465
 task_work_run+0x251/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa11/0x27f0 kernel/exit.c:953
 do_group_exit+0x207/0x2c0 kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88805898c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 3152 bytes inside of
 freed 8192-byte region [ffff88805898c000, ffff88805898e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58988
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 ffff88801b042280 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042280 0000000000000000 dead000000000001
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001626201 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 7351, tgid 7349 (syz.0.375), ts 136879915714, free_ts 136861177750
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1714
 prep_new_page mm/page_alloc.c:1722 [inline]
 get_page_from_freelist+0x361c/0x37c0 mm/page_alloc.c:3696
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4978
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2468 [inline]
 allocate_slab+0x8f/0x3b0 mm/slub.c:2632
 new_slab mm/slub.c:2686 [inline]
 ___slab_alloc+0xc3b/0x1500 mm/slub.c:3872
 __slab_alloc+0x58/0xa0 mm/slub.c:3962
 __slab_alloc_node mm/slub.c:4037 [inline]
 slab_alloc_node mm/slub.c:4198 [inline]
 __kmalloc_cache_noprof+0x26a/0x370 mm/slub.c:4367
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 mr_table_alloc+0x65/0x260 net/ipv4/ipmr_base.c:41
 ip6mr_new_table net/ipv6/ip6mr.c:411 [inline]
 ip6mr_rules_init net/ipv6/ip6mr.c:254 [inline]
 ip6mr_net_init+0x219/0x390 net/ipv6/ip6mr.c:1344
 ops_init+0x349/0x5b0 net/core/net_namespace.c:138
 setup_net+0x222/0x540 net/core/net_namespace.c:440
 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:572
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x5e2/0xad0 kernel/fork.c:3375
page last free pid 13 tgid 13 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0xdee/0x10b0 mm/page_alloc.c:2721
 discard_slab mm/slub.c:2730 [inline]
 __put_partials+0x160/0x1c0 mm/slub.c:3199
 put_cpu_partial+0x17e/0x250 mm/slub.c:3274
 __slab_free+0x294/0x390 mm/slub.c:4526
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4161 [inline]
 slab_alloc_node mm/slub.c:4210 [inline]
 kmem_cache_alloc_node_noprof+0x1f2/0x3b0 mm/slub.c:4262
 __alloc_skb+0x1c2/0x480 net/core/skbuff.c:658
 alloc_skb include/linux/skbuff.h:1340 [inline]
 nlmsg_new include/net/netlink.h:1035 [inline]
 inet_netconf_notify_devconf+0x15a/0x220 net/ipv4/devinet.c:2210
 __devinet_sysctl_unregister net/ipv4/devinet.c:2705 [inline]
 devinet_sysctl_unregister net/ipv4/devinet.c:2729 [inline]
 inetdev_destroy net/ipv4/devinet.c:334 [inline]
 inetdev_event+0x855/0x1740 net/ipv4/devinet.c:1656
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2266 [inline]
 call_netdevice_notifiers net/core/dev.c:2280 [inline]
 unregister_netdevice_many_notify+0x16b7/0x2640 net/core/dev.c:12036
 ops_exit_rtnl_list net/core/net_namespace.c:188 [inline]
 ops_undo_list+0x35e/0x8b0 net/core/net_namespace.c:246
 cleanup_net+0x530/0x940 net/core/net_namespace.c:684
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319

Memory state around the buggy address:
 ffff88805898cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805898cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805898cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88805898cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805898cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================