stdio: fix detection of malformated format strings

the error code returned by vsnprintf was ignored,
resulting in printing the string from a previous print.

Change-Id: I8506b05d56da55d1357a1234917adf341b46e1db
This commit is contained in:
Kévin Redon
2018-08-28 19:27:34 +02:00
parent 29200c6223
commit c171112994

View File

@@ -429,12 +429,17 @@ signed int vsprintf(char *pString, const char *pFormat, va_list ap)
signed int vfprintf(FILE *pStream, const char *pFormat, va_list ap)
{
char pStr[MAX_STRING_SIZE];
char pError[] = "stdio.c: increase MAX_STRING_SIZE\n\r";
// Write formatted string in buffer
if (vsprintf(pStr, pFormat, ap) >= MAX_STRING_SIZE) {
fputs(pError, stderr);
int rc = vsprintf(pStr, pFormat, ap);
if (rc < 0) {
fputs("format string error in ", stderr);
fputs(pFormat, stderr);
return rc;
}
if (rc >= MAX_STRING_SIZE) {
fputs("stdio.c: increase MAX_STRING_SIZE\n\r", stderr);
return rc;
}
// Display string
@@ -454,12 +459,17 @@ signed int vfprintf(FILE *pStream, const char *pFormat, va_list ap)
signed int vfprintf_sync(FILE *pStream, const char *pFormat, va_list ap)
{
char pStr[MAX_STRING_SIZE];
char pError[] = "stdio.c: increase MAX_STRING_SIZE\n\r";
// Write formatted string in buffer
if (vsprintf(pStr, pFormat, ap) >= MAX_STRING_SIZE) {
fputs_sync(pError, stderr);
int rc = vsprintf(pStr, pFormat, ap);
if (rc < 0) {
fputs_sync("format string error in ", stderr);
fputs_sync(pFormat, stderr);
return rc;
}
if (rc >= MAX_STRING_SIZE) {
fputs_sync("stdio.c: increase MAX_STRING_SIZE\n\r", stderr);
return rc;
}
// Display string