[MTX-3853] Fix integer overflows in libfastjson

2 files changed, 85 insertions, 0 deletions

diff --git a/recipes-extended/libfastjson/libfastjson/CVE-2020-12762.patch b/recipes-extended/libfastjson/libfastjson/CVE-2020-12762.patch
new file mode 100644
index 0000000..84e8206
--- /dev/null
+++ b/recipes-extended/libfastjson/libfastjson/CVE-2020-12762.patch
@@ -0,0 +1,80 @@
+From 73d5726b116e89d1e756419ceea5ed071d211642 Mon Sep 17 00:00:00 2001
+From: "mykola.salomatin" <mykola.salomatin@globallogic.com>
+Date: Tue, 2 Mar 2021 13:22:21 +0200
+Subject: [PATCH] Fix integer overflows
+
+This commit is a backport of the following commit in json-c:
+  * d07b91014986900a3a75f306d302e13e005e9d67
+
+In component json-c, several files were affected:
+  * linkhash.c
+  * arraylist.c
+  * printbuf.c
+
+In the current version of the libfastjson (0.99.8):
+  * linkhash.c was removed,
+  * arraylist.c doesn't have a necessary function for patching,
+  * printbuf.c is patched manually in current patch.
+
+---
+CVE: CVE-2020-12762
+Signed-off-by: Mykola Salomatin
+
+ printbuf.c | 20 +++++++++++++++++---
+ 1 file changed, 17 insertions(+), 3 deletions(-)
+
+diff --git a/printbuf.c b/printbuf.c
+index cc0f0d2..97e3ddd 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)
+ 	{
+-- 
+2.7.4
+
diff --git a/recipes-extended/libfastjson/libfastjson_%.bbappend b/recipes-extended/libfastjson/libfastjson_%.bbappend
new file mode 100644
index 0000000..103c92e
--- /dev/null
+++ b/recipes-extended/libfastjson/libfastjson_%.bbappend
@@ -0,0 +1,5 @@
+FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+
+PR.=".mlinux1"
+
+SRC_URI += "file://CVE-2020-12762.patch"