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BUG: KASAN: slab-use-after-free in hci_uart_write_work+0x81c/0x950 drivers/bluetooth/hci_ldisc.c:165
Read of size 4 at addr ffff888021816f70 by task kworker/0:2/1328

CPU: 0 UID: 0 PID: 1328 Comm: kworker/0:2 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 04/01/2014
Workqueue: events hci_uart_write_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595
 hci_uart_write_work+0x81c/0x950 drivers/bluetooth/hci_ldisc.c:165
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 54:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_node_noprof+0x303/0x880 mm/slub.c:5315
 __alloc_skb+0x156/0x410 net/core/skbuff.c:679
 alloc_skb include/linux/skbuff.h:1383 [inline]
 bcsp_prepare_pkt+0xe0/0xa90 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+0x4d9/0x950 drivers/bluetooth/hci_ldisc.c:161
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 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 ffff888021816f00
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 112 bytes inside of
 freed 240-byte region [ffff888021816f00, ffff888021816ff0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21816
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888025951201
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801cb6e8c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000190019 00000000f5000000 ffff888025951201
head: 00fff00000000040 ffff88801cb6e8c0 dead000000000100 dead000000000122
head: 0000000000000000 0000000000190019 00000000f5000000 ffff888025951201
head: 00fff00000000001 ffffea0000860581 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 13, tgid 13 (kworker/u32:1), ts 183390218740, free_ts 123018875924
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240
 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+0x2c4/0x440 mm/slub.c:3302
 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656
 __slab_alloc.isra.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_node_noprof+0x51e/0x880 mm/slub.c:5315
 __alloc_skb+0x156/0x410 net/core/skbuff.c:679
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 inet6_ifa_notify net/ipv6/addrconf.c:5610 [inline]
 __ipv6_ifa_notify+0x1f1/0xf90 net/ipv6/addrconf.c:6270
 ipv6_ifa_notify net/ipv6/addrconf.c:6322 [inline]
 addrconf_dad_completed+0x195/0xff0 net/ipv6/addrconf.c:4320
 addrconf_dad_begin net/ipv6/addrconf.c:4122 [inline]
 addrconf_dad_work+0xb1e/0x1360 net/ipv6/addrconf.c:4227
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
page last free pid 60 tgid 60 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973
 discard_slab mm/slub.c:3346 [inline]
 __put_partials+0x127/0x160 mm/slub.c:3886
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 __kmalloc_cache_noprof+0x2e1/0x810 mm/slub.c:5775
 kmalloc_noprof include/linux/slab.h:957 [inline]
 usb_control_msg+0xbc/0x4a0 drivers/usb/core/message.c:144
 usb_clear_port_feature drivers/usb/core/hub.c:456 [inline]
 hub_port_reset+0x6b7/0x1c60 drivers/usb/core/hub.c:3113
 hub_port_init+0x1f2/0x37f0 drivers/usb/core/hub.c:4939
 hub_port_connect drivers/usb/core/hub.c:5496 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2f27/0x4af0 drivers/usb/core/hub.c:5953
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 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:
 ffff888021816e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888021816e80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff888021816f00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff888021816f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff888021817000: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
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