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BUG: KASAN: slab-out-of-bounds in vsnprintf+0x1086/0x1c50 lib/vsprintf.c:2503
Read of size 8 at addr ffff8880895a18b8 by task syz-executor.1/10666

CPU: 0 PID: 10666 Comm: syz-executor.1 Not tainted 5.3.0-rc1+ #50
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:

Allocated by task 0:
(stack is not available)

Freed by task 8:
(stack is not available)

The buggy address belongs to the object at ffff8880895a0580
 which belongs to the cache names_cache of size 4096
The buggy address is located 824 bytes to the right of
 4096-byte region [ffff8880895a0580, ffff8880895a1580)
The buggy address belongs to the page:
page:ffffea0002256800 refcount:1 mapcount:0 mapping:ffff8880aa5918c0 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea000246f288 ffffea000246f888 ffff8880aa5918c0
raw: 0000000000000000 ffff8880895a0580 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880895a1780: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8880895a1800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880895a1880: fc fc fc fc fc fc fc fc 00 00 00 00 f1 f1 f1 f1
                                        ^
 ffff8880895a1900: 00 00 00 f3 f3 f3 f3 f3 fc fc fc fc fc fc fc fc
 ffff8880895a1980: fc fc fc fc fc fc fc fc 00 00 00 00 f1 f1 f1 f1
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