[PATCH] [CVE-2022-29824] Fix integer overflows in xmlBuf and xmlBuffer

[PATCH] [CVE-2022-29824] Fix integer overflows in xmlBuf and xmlBuffer

From 6c283d83eccd940bcde15634ac8c7f100e3caefd Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Tue, 8 Mar 2022 20:10:02 +0100

In several places, the code handling string buffers didn't check for
integer overflow or used wrong types for buffer sizes. This could
result in out-of-bounds writes or other memory errors when working on
large, multi-gigabyte buffers.

Thanks to Felix Wilhelm for the report.

Change-Id: If3a2ec6b91d5ddcbea476ad674d85476a37d2c07
Signed-off-by: JinWang An <jinwang.an@samsung.com>