Description:
1. once new socket is added, "strncpy" is used to copy instance_name
from source string to dest, but it does not guarantee null terminated.
2. there is a memory overwrite risk when it get instance_name from
a file's name
Solution:
1. we bounded length of string instance_name to ensure it is
"null-terminated".
2. limit the copy length when instance_name is get
Test Case:
1. success to build and deploy 1 controller + 1 compute (virtual)
2. trigger memory overwrite in a debug version with some logs added.
With origin code, "instance_name" in function "file_to_instance_name()"
is assigned to a string whose length is greater than its capacity.
With patch code, "instance_name" has a limit assign length
and a null terminate.
Reproduce:
To trigger memory overwrite case, a socket file with super long name is
generated under "/var/lib/libvirt/qemu/" which is monitored by this software
Closes-Bug: 1794704
Signed-off-by: SidneyAn <ran1.an@intel.com>
Change-Id: Ifb97e3dc1b59ebdc23cda73731fb02dc342d0520
9d0703d95f