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BUG: KASAN: slab-out-of-bounds in vsnprintf+0x1727/0x19a0 lib/vsprintf.c:2503
Read of size 8 at addr ffff8880a53a90c0 by task syz-executor.5/9176

CPU: 0 PID: 9176 Comm: syz-executor.5 Not tainted 5.2.0-rc7-next-20190703 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:

Allocated by task 1024:
(stack is not available)

Freed by task 2313309088:
usercopy: Kernel memory overwrite attempt detected to SLAB object 'kernfs_node_cache' (offset 216, size 1)!
------------[ cut here ]------------
Bad or missing usercopy whitelist? Kernel memory overwrite attempt detected to SLAB object 'kernfs_node_cache' (offset 96, size 2)!
WARNING: CPU: 0 PID: 9176 at mm/usercopy.c:74 usercopy_warn+0xeb/0x110 mm/usercopy.c:74
Kernel panic - not syncing: panic_on_warn set ...
Kernel Offset: disabled