From c171112994117b172ef4394cbb4d85ab6326369b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?K=C3=A9vin=20Redon?= Date: Tue, 28 Aug 2018 19:27:34 +0200 Subject: [PATCH] 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 --- firmware/libcommon/source/stdio.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/firmware/libcommon/source/stdio.c b/firmware/libcommon/source/stdio.c index 2bfaed7d..a8612d18 100644 --- a/firmware/libcommon/source/stdio.c +++ b/firmware/libcommon/source/stdio.c @@ -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