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BUG: KASAN: slab-use-after-free in hci_uart_write_work+0x82d/0x960 drivers/bluetooth/hci_ldisc.c:165
Read of size 4 at addr ffff88804b7d8930 by task kworker/0:0/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events hci_uart_write_work
Call Trace:
 <TASK>
 __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
 hci_uart_write_work+0x82d/0x960 drivers/bluetooth/hci_ldisc.c:165
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_node_noprof+0x298/0x800 mm/slub.c:5315
 __alloc_skb+0x156/0x410 net/core/skbuff.c:679
 alloc_skb include/linux/skbuff.h:1383 [inline]
 bcsp_prepare_pkt+0xe0/0xae0 drivers/bluetooth/hci_bcsp.c:218
 bcsp_dequeue+0x237/0x4b0 drivers/bluetooth/hci_bcsp.c:308
 hci_uart_dequeue drivers/bluetooth/hci_ldisc.c:107 [inline]
 hci_uart_write_work+0x4e3/0x960 drivers/bluetooth/hci_ldisc.c:161
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

The buggy address belongs to the object at ffff88804b7d88c0
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 112 bytes inside of
 freed 240-byte region [ffff88804b7d88c0, ffff88804b7d89b0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4b7d8
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88804044ea00 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080190019 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88804044ea00 dead000000000122 0000000000000000
head: 0000000000000000 0000000080190019 00000000f5000000 0000000000000000
head: 04fff00000000001 ffffea00012df601 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 11962, tgid 11956 (syz.3.1163), ts 649537204938, free_ts 647892165586
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab mm/slub.c:3248 [inline]
 new_slab+0x2c3/0x430 mm/slub.c:3302
 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 kmem_cache_alloc_noprof+0x44d/0x770 mm/slub.c:5270
 skb_clone+0x190/0x3f0 net/core/skbuff.c:2087
 do_one_broadcast net/netlink/af_netlink.c:1455 [inline]
 netlink_broadcast_filtered+0xb76/0xf90 net/netlink/af_netlink.c:1533
 netlink_broadcast+0x39/0x50 net/netlink/af_netlink.c:1557
 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline]
 kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
 kobject_uevent_env+0xcbc/0x1920 lib/kobject_uevent.c:608
 device_add+0x1103/0x1980 drivers/base/core.c:3670
 hci_register_dev+0x328/0xce0 net/bluetooth/hci_core.c:2621
 hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:691 [inline]
 hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:717 [inline]
 hci_uart_tty_ioctl+0x89e/0xc80 drivers/bluetooth/hci_ldisc.c:771
 tty_compat_ioctl+0x384/0x4d0 drivers/tty/tty_io.c:2980
page last free pid 9 tgid 9 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943
 discard_slab mm/slub.c:3346 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3886
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 __kmalloc_cache_noprof+0x282/0x800 mm/slub.c:5771
 kmalloc_noprof include/linux/slab.h:957 [inline]
 usb_control_msg+0xbc/0x4a0 drivers/usb/core/message.c:144
 get_port_status drivers/usb/core/hub.c:607 [inline]
 hub_ext_port_status+0x14e/0x670 drivers/usb/core/hub.c:624
 usb_hub_port_status drivers/usb/core/hub.c:674 [inline]
 hub_port_debounce+0x1a2/0x3f0 drivers/usb/core/hub.c:4705
 hub_port_debounce_be_stable drivers/usb/core/hub.h:184 [inline]
 hub_port_connect drivers/usb/core/hub.c:5419 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x37f7/0x52f0 drivers/usb/core/hub.c:5953
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Memory state around the buggy address:
 ffff88804b7d8800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
 ffff88804b7d8880: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88804b7d8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88804b7d8980: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
 ffff88804b7d8a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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