fix CVE-2021-3672 c-ares bug

cmake/external_libs/c-ares.cmake

@@ -15,7 +15,8 @@ mindspore_add_pkg(c-ares
         -DCARES_SHARED:BOOL=OFF
         -DCARES_STATIC:BOOL=ON
         -DCARES_STATIC_PIC:BOOL=ON
-        -DHAVE_LIBNSL:BOOL=OFF)
+        -DHAVE_LIBNSL:BOOL=OFF
+        PATCHES ${CMAKE_SOURCE_DIR}/third_party/patch/c-ares/CVE-2021-3672.patch)
 
 include_directories(${c-ares_INC})
 add_library(mindspore::cares ALIAS c-ares::cares)

third_party/patch/c-ares/CVE-2021-3672.patch

@@ -0,0 +1,105 @@
+diff -Npur c-ares-1.15.0/ares_expand_name.c c-ares-1.15.0-new/ares_expand_name.c
+--- c-ares-1.15.0/ares_expand_name.c	2017-07-03 17:04:19.000000000 +0800
++++ c-ares-1.15.0-new/ares_expand_name.c	2021-08-21 22:48:24.650973166 +0800
+@@ -38,6 +38,26 @@
+ static int name_length(const unsigned char *encoded, const unsigned char *abuf,
+                        int alen);
+ 
++/* Reserved characters for names that need to be escaped */
++static int is_reservedch(int ch)
++{
++  switch (ch) {
++    case '"':
++    case '.':
++    case ';':
++    case '\\':
++    case '(':
++    case ')':
++    case '@':
++    case '$':
++      return 1;
++    default:
++      break;
++  }
++
++  return 0;
++}
++
+ /* Expand an RFC1035-encoded domain name given by encoded.  The
+  * containing message is given by abuf and alen.  The result given by
+  * *s, which is set to a NUL-terminated allocated buffer.  *enclen is
+@@ -113,18 +133,37 @@ int ares_expand_name(const unsigned char
+         }
+       else
+         {
+-          len = *p;
++          int name_len = *p;
++          len = name_len;
+           p++;
++
+           while (len--)
+             {
+-              if (*p == '.' || *p == '\\')
+-                *q++ = '\\';
+-              *q++ = *p;
++              /* Output as \DDD for consistency with RFC1035 5.1, except
++               * for the special case of a root name response  */
++              if (!isprint(*p) && !(name_len == 1 && *p == 0))
++                {
++
++                  *q++ = '\\';
++                  *q++ = '0' + *p / 100;
++                  *q++ = '0' + (*p % 100) / 10;
++                  *q++ = '0' + (*p % 10);
++                }
++              else if (is_reservedch(*p))
++                {
++                  *q++ = '\\';
++                  *q++ = *p;
++                }
++              else
++                {
++                  *q++ = *p;
++                }
+               p++;
+             }
+           *q++ = '.';
+         }
+-    }
++     }
++
+   if (!indir)
+     *enclen = aresx_uztosl(p + 1U - encoded);
+ 
+@@ -171,15 +210,29 @@ static int name_length(const unsigned ch
+         }
+       else if (top == 0x00)
+         {
+-          offset = *encoded;
++          int name_len = *encoded;
++          offset = name_len;
+           if (encoded + offset + 1 >= abuf + alen)
+             return -1;
+           encoded++;
++
+           while (offset--)
+             {
+-              n += (*encoded == '.' || *encoded == '\\') ? 2 : 1;
++              if (!isprint(*encoded) && !(name_len == 1 && *encoded == 0))
++                {
++                  n += 4;
++                }
++              else if (is_reservedch(*encoded))
++                {
++                  n += 2;
++                }
++              else
++                {
++                  n += 1;
++                }
+               encoded++;
+             }
++
+           n++;
+         }
+       else