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BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x2b0
Write of size 4 at addr ffff88810f2ec010 by task kworker/u11:1/5218

CPU: 1 UID: 0 PID: 5218 Comm: kworker/u11:1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: hci1 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 kasan_check_range+0x2b0/0x2c0
 hci_conn_drop+0x34/0x2b0
 hci_cmd_sync_work+0x262/0x400
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 57:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x3e2/0x700
 __hci_conn_add+0x3c5/0x1b30
 le_conn_complete_evt+0x6f6/0x1420
 hci_le_conn_complete_evt+0x187/0x480
 hci_event_packet+0x78f/0x1260
 hci_rx_work+0x3ee/0x1060
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30

Freed by task 57:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c0/0x660
 device_release+0x9e/0x1d0
 kobject_put+0x228/0x570
 hci_conn_del+0xc36/0x1240
 hci_disconn_complete_evt+0x64e/0x950
 hci_event_packet+0x7e3/0x1260
 hci_rx_work+0x3ee/0x1060
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff88810f2ec000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 16 bytes inside of
 freed 8192-byte region [ffff88810f2ec000, ffff88810f2ee000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f2e8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100042280 ffffea0005cc6a00 dead000000000002
raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100042280 ffffea0005cc6a00 dead000000000002
head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 017ff00000000003 ffffea00043cba01 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 174, tgid 174 (kworker/u9:5), ts 357847804155, free_ts 357836292058
 post_alloc_hook+0x23d/0x2a0
 get_page_from_freelist+0x22f6/0x23d0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x86/0x3b0
 ___slab_alloc+0xf2b/0x1960
 __slab_alloc+0x65/0x100
 __kmalloc_noprof+0x47d/0x800
 __sta_info_alloc+0xce6/0x2640
 ieee80211_ibss_add_sta+0x5b7/0x870
 ieee80211_ibss_rx_queued_mgmt+0x179a/0x2af0
 ieee80211_iface_work+0x85f/0x12d0
 cfg80211_wiphy_work+0x2ab/0x450
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
page last free pid 13256 tgid 13256 stack trace:
 __free_frozen_pages+0xb99/0xd10
 __slab_free+0x21b/0x2a0
 qlist_free_all+0x97/0x100
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_cache_node_noprof+0x409/0x700
 __get_vm_area_node+0x13f/0x300
 __vmalloc_node_range_noprof+0x371/0x16a0
 vzalloc_noprof+0xb2/0xf0
 alloc_counters+0xd3/0x6d0
 do_ip6t_get_ctl+0xa94/0x1180
 nf_getsockopt+0x26e/0x290
 ipv6_getsockopt+0x1ed/0x290
 do_sock_getsockopt+0x2b4/0x3d0
 __x64_sys_getsockopt+0x1a5/0x250
 do_syscall_64+0xfa/0xf80

Memory state around the buggy address:
 ffff88810f2ebf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810f2ebf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88810f2ec000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88810f2ec080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810f2ec100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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