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BUG: KASAN: use-after-free in device_for_each_child+0x17a/0x190 drivers/base/core.c:4044
Read of size 8 at addr ffff88807d5355f8 by task kbnepd bnep0/6351

CPU: 1 PID: 6351 Comm: kbnepd bnep0 Not tainted 6.9.0-rc5-syzkaller-00031-g71b1543c83d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 device_for_each_child+0x17a/0x190 drivers/base/core.c:4044
 pm_runtime_set_memalloc_noio+0xf2/0x180 drivers/base/power/runtime.c:248
 netdev_unregister_kobject+0x1ed/0x270 net/core/net-sysfs.c:2106
 unregister_netdevice_many_notify+0xc8a/0x19f0 net/core/dev.c:11135
 unregister_netdevice_many net/core/dev.c:11163 [inline]
 unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11042
 unregister_netdevice include/linux/netdevice.h:3115 [inline]
 unregister_netdev+0x1c/0x30 net/core/dev.c:11181
 bnep_session+0x220d/0x2d60 net/bluetooth/bnep/core.c:525
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x7d535
head: order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000002 ffffea0001f54d01 dead000000000122 00000000ffffffff
raw: 0000000400000000 0000000000000000 00000000ffffffff 0000000000000000
head: 00fff80000000840 ffff888018e9ba00 dead000000000122 0000000000000000
head: 0000000000000000 0000000000150015 00000001ffffffff 0000000000000000
head: 00fff80000000002 ffffea0001f54d01 dead000000000122 00000000ffffffff
head: 0000000400000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 7252, tgid -1548858213 (dhcpcd-run-hook), ts 7252, free_ts 230166524482
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2391
 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc_node+0x10a/0x340 mm/slub.c:3888
 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:577
 __alloc_skb+0x164/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1313 [inline]
 ndisc_alloc_skb+0x135/0x330 net/ipv6/ndisc.c:422
 ndisc_send_rs+0x371/0x690 net/ipv6/ndisc.c:703
 addrconf_rs_timer+0x422/0x850 net/ipv6/addrconf.c:4038
 call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1793
 expire_timers kernel/time/timer.c:1844 [inline]
 __run_timers+0x74b/0xaf0 kernel/time/timer.c:2418
 __run_timer_base kernel/time/timer.c:2429 [inline]
 __run_timer_base kernel/time/timer.c:2422 [inline]
 run_timer_base+0x111/0x190 kernel/time/timer.c:2438
 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2448
page last free pid 6107 tgid 6107 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 __folio_put_large+0x10d/0x1c0 mm/swap.c:132
 __folio_put+0x1c0/0x1f0 mm/swap.c:140
 hci_release_dev+0x525/0x660 net/bluetooth/hci_core.c:2833
 bt_host_release+0x6a/0xb0 net/bluetooth/hci_sysfs.c:94
 device_release+0xa1/0x240 drivers/base/core.c:2580
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1fa/0x5b0 lib/kobject.c:737
 put_device+0x1f/0x30 drivers/base/core.c:3828
 vhci_release+0x87/0x100 drivers/bluetooth/hci_vhci.c:675
 __fput+0x270/0xb80 fs/file_table.c:422
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa7d/0x2c10 kernel/exit.c:878
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
 get_signal+0x2616/0x2710 kernel/signal.c:2911
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310

Memory state around the buggy address:
 ffff88807d535480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807d535500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807d535580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff88807d535600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d535680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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