cpp/openttd-patchpack/source Changeset - r14951:e24469d4e684

Changeset - r14951:e24469d4e684

Parent rev.

Child rev.

[Not reviewed]

master

0 3 0

yexo - 14 years ago 2010-04-06 21:16:36
yexo@openttd.org

(svn r19569) -Fix: possible buffer underflow in newgrf string code

3 files changed with 5 insertions and 4 deletions:

src/newgrf_text.cpp

src/newgrf_text.h

src/strings.cpp

0 comments (0 inline, 0 general)

src/newgrf_text.cpp

➞

Show inline comments

@@ @@ -633,13 +633,13 @@ void RewindTextRefStack() @@
  * @param scc   the string control code that has been read
  * @param buff  the buffer we're writing to
  * @param str   the string that we need to write
  * @param argv  the OpenTTD stack of values
  * @return the string control code to "execute" now
  */
 uint RemapNewGRFStringControlCode(uint scc, char **buff, const char **str, int64 *argv)
+uint RemapNewGRFStringControlCode(uint scc, char *buf_start, char **buff, const char **str, int64 *argv)
+{
 	if (_newgrf_textrefstack->used) {
 		switch (scc) {
 			default: NOT_REACHED();
 			case SCC_NEWGRF_PRINT_SIGNED_BYTE:    *argv = _newgrf_textrefstack->PopSignedByte();    break;
 			case SCC_NEWGRF_PRINT_SIGNED_WORD:    *argv = _newgrf_textrefstack->PopSignedWord();    break;
@@ @@ -660,13 +660,13 @@ uint RemapNewGRFStringControlCode(uint s @@
 			case SCC_NEWGRF_PRINT_MONTH_YEAR:     *argv = _newgrf_textrefstack->PopSignedWord() + DAYS_TILL_ORIGINAL_BASE_YEAR; break;
 			case SCC_NEWGRF_DISCARD_WORD:         _newgrf_textrefstack->PopUnsignedWord(); break;
 			case SCC_NEWGRF_ROTATE_TOP_4_WORDS:   _newgrf_textrefstack->RotateTop4Words(); break;
 			case SCC_NEWGRF_PUSH_WORD:            _newgrf_textrefstack->PushWord(Utf8Consume(str)); break;
-			case SCC_NEWGRF_UNPRINT:              *buff -= Utf8Consume(str); break;
+			case SCC_NEWGRF_UNPRINT:              *buff = max(*buff - Utf8Consume(str), buf_start); break;
 			case SCC_NEWGRF_PRINT_STRING_ID:
 				*argv = TTDPStringIDToOTTDStringIDMapping(_newgrf_textrefstack->PopUnsignedWord());
 				break;
+		}
+	}

src/newgrf_text.h

➞

Show inline comments

@@ @@ -25,11 +25,11 @@ bool CheckGrfLangID(byte lang_id, byte g @@
 void PrepareTextRefStackUsage(byte numEntries);
 void StopTextRefStackUsage();
 void SwitchToNormalRefStack();
 void SwitchToErrorRefStack();
 void RewindTextRefStack();
 uint RemapNewGRFStringControlCode(uint scc, char **buff, const char **str, int64 *argv);
+uint RemapNewGRFStringControlCode(uint scc, char *buf_start, char **buff, const char **str, int64 *argv);
 StringID TTDPStringIDToOTTDStringIDMapping(StringID string);
 #endif /* NEWGRF_TEXT_H */

src/strings.cpp

➞

Show inline comments

@@ @@ -551,17 +551,18 @@ uint ConvertDisplaySpeedToSpeed(uint spe @@
 static char *FormatString(char *buff, const char *str, int64 *argv, uint casei, const char *last)
+{
 	WChar b;
 	int64 *argv_orig = argv;
 	uint modifier = 0;
 	char *buf_start = buff;
 	while ((b = Utf8Consume(&str)) != '\0') {
 		if (SCC_NEWGRF_FIRST <= b && b <= SCC_NEWGRF_LAST) {
 			/* We need to pass some stuff as it might be modified; oh boy. */
 			b = RemapNewGRFStringControlCode(b, &buff, &str, argv);
+			b = RemapNewGRFStringControlCode(b, buf_start, &buff, &str, argv);
 			if (b == 0) continue;
+		}
 		switch (b) {
 			case SCC_SETX: // {SETX}
 				if (buff + Utf8CharLen(SCC_SETX) + 1 < last) {

0 comments (0 inline, 0 general)