From c5de6b46d5bcda33ee11a03906c219361481c393 Mon Sep 17 00:00:00 2001
From: Rodrigo Garcia <Rodrigo.Garcia@espressif.com>
Date: Fri, 14 Jan 2022 09:30:22 -0300
Subject: [PATCH 1/7] Fixes String(float) issue with Stack Smashing

---
 cores/esp32/WString.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cores/esp32/WString.cpp b/cores/esp32/WString.cpp
index b78cf2eed90..0455cfaad70 100644
--- a/cores/esp32/WString.cpp
+++ b/cores/esp32/WString.cpp
@@ -114,13 +114,13 @@ String::String(unsigned long value, unsigned char base) {
 
 String::String(float value, unsigned char decimalPlaces) {
     init();
-    char buf[33];
+    char buf[34];
     *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
 }
 
 String::String(double value, unsigned char decimalPlaces) {
     init();
-    char buf[33];
+    char buf[34];
     *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
 }
 

From 1c459879da0dec07ccc769833ebd6342dfbd1afb Mon Sep 17 00:00:00 2001
From: Rodrigo Garcia <Rodrigo.Garcia@espressif.com>
Date: Fri, 14 Jan 2022 15:20:27 -0300
Subject: [PATCH 2/7] Fixes String(float) issue with Stack Smashing

---
 cores/esp32/stdlib_noniso.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/cores/esp32/stdlib_noniso.c b/cores/esp32/stdlib_noniso.c
index 8f24520dac3..cb598d869e5 100644
--- a/cores/esp32/stdlib_noniso.c
+++ b/cores/esp32/stdlib_noniso.c
@@ -88,6 +88,32 @@ char* ultoa(unsigned long value, char* result, int base) {
     return result;
 }
 
+#if 1
+// This version is intended to be user proof
+// It avoids Stack Smashing issue, even for s = String(-234223.4f, 32) or String(0.0f, 100) 
+char *dtostrf(double number, signed char width, unsigned char prec, char *s) {
+  char fmt[34];
+  // calculates how many characters the integer part of the float will take
+  sprintf(fmt, "%32.0f", number);
+  // finds the start of number ignoring the blanks
+  char *start = fmt;
+  while (*start == ' ') start++;
+  unsigned char numSize = strlen(start), maxSize = sizeof(fmt) - 1;
+  int maxPrec;
+
+  if (prec) numSize += 1; // for the '.'
+
+  // avoiding Stack smashing protect failure!
+  if (width > maxSize) width = maxSize;
+  maxPrec = maxSize - numSize;
+  prec = maxPrec > 0 ? maxPrec : 0;
+  
+  sprintf(fmt, "%%%d.%df", width, prec);
+  sprintf(s, fmt, number);
+  return s;
+}
+#else
+// orginal code from Arduino ESP8266
 char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
     bool negative = false;
 
@@ -160,3 +186,4 @@ char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
     *out = 0;
     return s;
 }
+#endif

From f3c7b4980ded4d75af5536cb4cb9691444dbe0f4 Mon Sep 17 00:00:00 2001
From: Rodrigo Garcia <Rodrigo.Garcia@espressif.com>
Date: Sun, 16 Jan 2022 18:34:21 -0300
Subject: [PATCH 3/7] Fixes String(float) issue with Stack Smashing

---
 cores/esp32/WString.cpp     |  8 +++---
 cores/esp32/stdlib_noniso.c | 49 +++++++++++++++++++++++--------------
 2 files changed, 34 insertions(+), 23 deletions(-)

diff --git a/cores/esp32/WString.cpp b/cores/esp32/WString.cpp
index 0455cfaad70..5434af73399 100644
--- a/cores/esp32/WString.cpp
+++ b/cores/esp32/WString.cpp
@@ -114,14 +114,14 @@ String::String(unsigned long value, unsigned char base) {
 
 String::String(float value, unsigned char decimalPlaces) {
     init();
-    char buf[34];
-    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
+    char buf[64];
+    *this = dtostrf(value, sizeof(buf) - 1, decimalPlaces, buf);
 }
 
 String::String(double value, unsigned char decimalPlaces) {
     init();
-    char buf[34];
-    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
+    char buf[64];
+    *this = dtostrf(value,  sizeof(buf) - 1, decimalPlaces, buf);
 }
 
 String::~String() {
diff --git a/cores/esp32/stdlib_noniso.c b/cores/esp32/stdlib_noniso.c
index cb598d869e5..b39e0369ca1 100644
--- a/cores/esp32/stdlib_noniso.c
+++ b/cores/esp32/stdlib_noniso.c
@@ -92,25 +92,36 @@ char* ultoa(unsigned long value, char* result, int base) {
 // This version is intended to be user proof
 // It avoids Stack Smashing issue, even for s = String(-234223.4f, 32) or String(0.0f, 100) 
 char *dtostrf(double number, signed char width, unsigned char prec, char *s) {
-  char fmt[34];
-  // calculates how many characters the integer part of the float will take
-  sprintf(fmt, "%32.0f", number);
-  // finds the start of number ignoring the blanks
-  char *start = fmt;
-  while (*start == ' ') start++;
-  unsigned char numSize = strlen(start), maxSize = sizeof(fmt) - 1;
-  int maxPrec;
-
-  if (prec) numSize += 1; // for the '.'
-
-  // avoiding Stack smashing protect failure!
-  if (width > maxSize) width = maxSize;
-  maxPrec = maxSize - numSize;
-  prec = maxPrec > 0 ? maxPrec : 0;
-  
-  sprintf(fmt, "%%%d.%df", width, prec);
-  sprintf(s, fmt, number);
-  return s;
+    char fmt[20];  // just for the formating in sprintf()
+    uint8_t numSize = 0;
+    int maxPrec;
+
+    if (isnan(number)) {
+        strcpy(s, "nan");
+        return s;
+    }
+    if (isinf(number)) {
+        strcpy(s, "inf");
+        return s;
+    }
+
+    // calculates how many characters the integer part of the float will take
+    if (number < 0) {   // number is negative
+        numSize = 1;    // for the '-' simbol
+    }
+    double n = fabs(number);
+    do {
+        numSize++;
+        n = n / 10;
+    } while (n > 1);
+    if (prec) numSize += 1; // for the '.'
+    // avoiding Stack smashing protect failure!
+    maxPrec = width - numSize;
+    if (prec) prec = maxPrec > 0 ? maxPrec : 0;
+
+    sprintf(fmt, "%%%d.%df", numSize, prec);
+    sprintf(s, fmt, number);
+    return s;
 }
 #else
 // orginal code from Arduino ESP8266

From c6ab73b04f07f60e1c0d229ba29df3a9038154ea Mon Sep 17 00:00:00 2001
From: Rodrigo Garcia <Rodrigo.Garcia@espressif.com>
Date: Sun, 16 Jan 2022 20:14:12 -0300
Subject: [PATCH 4/7] Fixes String(float) issue with Stack Smashing

---
 cores/esp32/WString.cpp     | 11 ++++++-----
 cores/esp32/stdlib_noniso.c | 38 -------------------------------------
 2 files changed, 6 insertions(+), 43 deletions(-)

diff --git a/cores/esp32/WString.cpp b/cores/esp32/WString.cpp
index 5434af73399..1021570211e 100644
--- a/cores/esp32/WString.cpp
+++ b/cores/esp32/WString.cpp
@@ -114,14 +114,15 @@ String::String(unsigned long value, unsigned char base) {
 
 String::String(float value, unsigned char decimalPlaces) {
     init();
-    char buf[64];
-    *this = dtostrf(value, sizeof(buf) - 1, decimalPlaces, buf);
-}
+    char *buf = (char*)malloc(decimalPlaces + 42);
+    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
+    free(buf);}
 
 String::String(double value, unsigned char decimalPlaces) {
     init();
-    char buf[64];
-    *this = dtostrf(value,  sizeof(buf) - 1, decimalPlaces, buf);
+    char *buf = (char*)malloc(decimalPlaces + 312);
+    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
+    free(buf);
 }
 
 String::~String() {
diff --git a/cores/esp32/stdlib_noniso.c b/cores/esp32/stdlib_noniso.c
index b39e0369ca1..8f24520dac3 100644
--- a/cores/esp32/stdlib_noniso.c
+++ b/cores/esp32/stdlib_noniso.c
@@ -88,43 +88,6 @@ char* ultoa(unsigned long value, char* result, int base) {
     return result;
 }
 
-#if 1
-// This version is intended to be user proof
-// It avoids Stack Smashing issue, even for s = String(-234223.4f, 32) or String(0.0f, 100) 
-char *dtostrf(double number, signed char width, unsigned char prec, char *s) {
-    char fmt[20];  // just for the formating in sprintf()
-    uint8_t numSize = 0;
-    int maxPrec;
-
-    if (isnan(number)) {
-        strcpy(s, "nan");
-        return s;
-    }
-    if (isinf(number)) {
-        strcpy(s, "inf");
-        return s;
-    }
-
-    // calculates how many characters the integer part of the float will take
-    if (number < 0) {   // number is negative
-        numSize = 1;    // for the '-' simbol
-    }
-    double n = fabs(number);
-    do {
-        numSize++;
-        n = n / 10;
-    } while (n > 1);
-    if (prec) numSize += 1; // for the '.'
-    // avoiding Stack smashing protect failure!
-    maxPrec = width - numSize;
-    if (prec) prec = maxPrec > 0 ? maxPrec : 0;
-
-    sprintf(fmt, "%%%d.%df", numSize, prec);
-    sprintf(s, fmt, number);
-    return s;
-}
-#else
-// orginal code from Arduino ESP8266
 char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
     bool negative = false;
 
@@ -197,4 +160,3 @@ char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
     *out = 0;
     return s;
 }
-#endif

From 7cbd148d5d3d5c2fbda5dbfc501b3625942d1e0b Mon Sep 17 00:00:00 2001
From: Rodrigo Garcia <Rodrigo.Garcia@espressif.com>
Date: Sun, 16 Jan 2022 20:45:43 -0300
Subject: [PATCH 5/7] Fixes String(float) issue with Stack Smashing

---
 cores/esp32/WString.cpp     | 4 ++--
 cores/esp32/WString.h       | 4 ++--
 cores/esp32/stdlib_noniso.c | 4 ++--
 cores/esp32/stdlib_noniso.h | 2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/cores/esp32/WString.cpp b/cores/esp32/WString.cpp
index 1021570211e..8e6d2be84ee 100644
--- a/cores/esp32/WString.cpp
+++ b/cores/esp32/WString.cpp
@@ -112,13 +112,13 @@ String::String(unsigned long value, unsigned char base) {
     *this = buf;
 }
 
-String::String(float value, unsigned char decimalPlaces) {
+String::String(float value, unsigned int decimalPlaces) {
     init();
     char *buf = (char*)malloc(decimalPlaces + 42);
     *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
     free(buf);}
 
-String::String(double value, unsigned char decimalPlaces) {
+String::String(double value, unsigned int decimalPlaces) {
     init();
     char *buf = (char*)malloc(decimalPlaces + 312);
     *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
diff --git a/cores/esp32/WString.h b/cores/esp32/WString.h
index 958b01792e8..3190a247dda 100644
--- a/cores/esp32/WString.h
+++ b/cores/esp32/WString.h
@@ -71,8 +71,8 @@ class String {
         explicit String(unsigned int, unsigned char base = 10);
         explicit String(long, unsigned char base = 10);
         explicit String(unsigned long, unsigned char base = 10);
-        explicit String(float, unsigned char decimalPlaces = 2);
-        explicit String(double, unsigned char decimalPlaces = 2);
+        explicit String(float, unsigned int decimalPlaces = 2);
+        explicit String(double, unsigned int decimalPlaces = 2);
         ~String(void);
 
         // memory management
diff --git a/cores/esp32/stdlib_noniso.c b/cores/esp32/stdlib_noniso.c
index 8f24520dac3..99168d14506 100644
--- a/cores/esp32/stdlib_noniso.c
+++ b/cores/esp32/stdlib_noniso.c
@@ -88,7 +88,7 @@ char* ultoa(unsigned long value, char* result, int base) {
     return result;
 }
 
-char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
+char * dtostrf(double number, signed char width, unsigned int prec, char *s) {
     bool negative = false;
 
     if (isnan(number)) {
@@ -117,7 +117,7 @@ char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
     // Round correctly so that print(1.999, 2) prints as "2.00"
     // I optimized out most of the divisions
     double rounding = 2.0;
-    for (uint8_t i = 0; i < prec; ++i)
+    for (uint32_t i = 0; i < prec; ++i)
         rounding *= 10.0;
     rounding = 1.0 / rounding;
 
diff --git a/cores/esp32/stdlib_noniso.h b/cores/esp32/stdlib_noniso.h
index 3df2cc2a1b6..308efbbce09 100644
--- a/cores/esp32/stdlib_noniso.h
+++ b/cores/esp32/stdlib_noniso.h
@@ -39,7 +39,7 @@ char* utoa (unsigned int val, char *s, int radix);
 
 char* ultoa (unsigned long val, char *s, int radix);
 
-char* dtostrf (double val, signed char width, unsigned char prec, char *s);
+char* dtostrf (double val, signed char width, unsigned int prec, char *s);
 
 #ifdef __cplusplus
 } // extern "C"

From 90e5b044791d9ac1ee38860deebd062955db3ee6 Mon Sep 17 00:00:00 2001
From: Rodrigo Garcia <Rodrigo.Garcia@espressif.com>
Date: Sun, 16 Jan 2022 20:59:34 -0300
Subject: [PATCH 6/7] Fixes String(float) issue with Stack Smashing

---
 cores/esp32/stdlib_noniso.c | 2 +-
 cores/esp32/stdlib_noniso.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/cores/esp32/stdlib_noniso.c b/cores/esp32/stdlib_noniso.c
index 99168d14506..e66edace7e3 100644
--- a/cores/esp32/stdlib_noniso.c
+++ b/cores/esp32/stdlib_noniso.c
@@ -88,7 +88,7 @@ char* ultoa(unsigned long value, char* result, int base) {
     return result;
 }
 
-char * dtostrf(double number, signed char width, unsigned int prec, char *s) {
+char * dtostrf(double number, signed int width, unsigned int prec, char *s) {
     bool negative = false;
 
     if (isnan(number)) {
diff --git a/cores/esp32/stdlib_noniso.h b/cores/esp32/stdlib_noniso.h
index 308efbbce09..e5bb44e563a 100644
--- a/cores/esp32/stdlib_noniso.h
+++ b/cores/esp32/stdlib_noniso.h
@@ -39,7 +39,7 @@ char* utoa (unsigned int val, char *s, int radix);
 
 char* ultoa (unsigned long val, char *s, int radix);
 
-char* dtostrf (double val, signed char width, unsigned int prec, char *s);
+char* dtostrf (double val, signed int width, unsigned int prec, char *s);
 
 #ifdef __cplusplus
 } // extern "C"

From 8eafb5efeeccf1a8ebca7cd8944c92f059f21aa9 Mon Sep 17 00:00:00 2001
From: Rodrigo Garcia <Rodrigo.Garcia@espressif.com>
Date: Sun, 16 Jan 2022 22:05:53 -0300
Subject: [PATCH 7/7] Fixes String(float) issue with Stack Smashing

---
 cores/esp32/WString.cpp | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/cores/esp32/WString.cpp b/cores/esp32/WString.cpp
index 8e6d2be84ee..ded2a3c1e78 100644
--- a/cores/esp32/WString.cpp
+++ b/cores/esp32/WString.cpp
@@ -115,14 +115,25 @@ String::String(unsigned long value, unsigned char base) {
 String::String(float value, unsigned int decimalPlaces) {
     init();
     char *buf = (char*)malloc(decimalPlaces + 42);
-    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
-    free(buf);}
+    if (buf) {
+        *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
+        free(buf);
+    } else {
+        *this = "nan";
+        log_e("No enought memory for the operation.");
+    }
+}
 
 String::String(double value, unsigned int decimalPlaces) {
     init();
     char *buf = (char*)malloc(decimalPlaces + 312);
-    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
-    free(buf);
+    if (buf) {
+        *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
+        free(buf);
+    } else {
+        *this = "nan";
+        log_e("No enought memory for the operation.");
+    }
 }
 
 String::~String() {