!18 fix CVE-2020-12762

From: @tong_1001 
Reviewed-by: @hubin95 
Signed-off-by: @hubin95

backport-CVE-2020-12762.patch

@@ -0,0 +1,66 @@
+From f51fcd59a8bbeb60eaf8ae0e398556be2fa3317a Mon Sep 17 00:00:00 2001
+From: Wang Haitao <wanghaitao.ouyang@foxmail.com>
+Date: Tue, 14 Mar 2023 22:25:54 +0800
+Subject: [PATCH] Fix CVE-2020-12762
+
+reference: https://github.com/json-c/json-c/pull/592/files
+
+I reproduce this CVE using the code from https://github.com/json-c/json-c/pull/592
+
+And it fix it and no more segmentation fault
+---
+ printbuf.c | 20 +++++++++++++++++---
+ 1 file changed, 17 insertions(+), 3 deletions(-)
+
+diff --git a/printbuf.c b/printbuf.c
+index e9cde11..b02a363 100644
+--- a/printbuf.c
++++ b/printbuf.c
+@@ -13,6 +13,7 @@
+ 
+ #include "config.h"
+ 
++#include <limits.h>
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <string.h>
+@@ -68,9 +69,16 @@ static int printbuf_extend(struct printbuf *p, int min_size)
+ 	if (p->size >= min_size)
+ 		return 0;
+ 
+-	new_size = p->size * 2;
+-	if (new_size < min_size + 8)
+-		new_size =  min_size + 8;
++	/* Prevent signed integer overflows with large buffers. */
++	if (min_size > INT_MAX - 8)
++		return -1;
++	if (p->size > INT_MAX / 2)
++		new_size = min_size + 8;
++	else {
++		new_size = p->size * 2;
++		if (new_size < min_size + 8)
++			new_size = min_size + 8;
++	}
+ #ifdef PRINTBUF_DEBUG
+ 	MC_DEBUG("printbuf_memappend: realloc "
+ 	  "bpos=%d min_size=%d old_size=%d new_size=%d\n",
+@@ -85,6 +93,9 @@ static int printbuf_extend(struct printbuf *p, int min_size)
+ 
+ int printbuf_memappend(struct printbuf *p, const char *buf, int size)
+ {
++	/* Prevent signed integer overflows with large buffers. */
++	if (size > INT_MAX - p->bpos - 1)
++		return -1;
+ 	if (p->size <= p->bpos + size + 1) {
+ 		if (printbuf_extend(p, p->bpos + size + 1) < 0)
+ 			return -1;
+@@ -136,6 +147,9 @@ int printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len)
+ 
+ 	if (offset == -1)
+ 		offset = pb->bpos;
++	/* Prevent signed integer overflows with large buffers. */
++	if (len > INT_MAX - offset)
++		return -1;
+ 	size_needed = offset + len;
+ 	if (pb->size < size_needed)
+ 	{

libfastjson.spec

@@ -1,11 +1,13 @@
 Name:		libfastjson
 Version:	0.99.9
-Release:	2
+Release:	3
 Summary:	JSON-C - A JSON implementation in C
 License:	MIT
 URL:		https://github.com/rsyslog/libfastjson
 Source0:	http://download.rsyslog.com/%{name}/%{name}-%{version}.tar.gz
 
+Patch1:        backport-CVE-2020-12762.patch
+
 BuildRequires: autoconf automake libtool
 
 %description
@@ -56,6 +58,9 @@ make V=1 check
 %{_libdir}/pkgconfig/libfastjson.pc
 
 %changelog
+* Tue Mar 28 2023 shixuantong <shixuantong1@huawei.com> - 0.99.9-3
+- fix CVE-2020-12762
+
 * Thu Sep 8 2022 panxiaohe <panxh.life@foxmail.com> - 0.99.9-2
 - fix obsoletes in spec