REVIEWED: `LoadFileData()` potential issues with dataSize

1 files changed, 22 insertions, 7 deletions

diff --git a/src/utils.c b/src/utils.c
index 27747b75..51d84cfe 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -200,7 +200,7 @@ unsigned char *LoadFileData(const char *fileName, int *dataSize)
             // WARNING: On binary streams SEEK_END could not be found,
             // using fseek() and ftell() could not work in some (rare) cases
             fseek(file, 0, SEEK_END);
-            int size = ftell(file);
+            int size = ftell(file);     // WARNING: ftell() returns 'long int', maximum size returned is INT_MAX (2147483647 bytes)
             fseek(file, 0, SEEK_SET);
 
             if (size > 0)
@@ -210,11 +210,24 @@ unsigned char *LoadFileData(const char *fileName, int *dataSize)
                 if (data != NULL)
                 {
                     // NOTE: fread() returns number of read elements instead of bytes, so we read [1 byte, size elements]
-                    unsigned int count = (unsigned int)fread(data, sizeof(unsigned char), size, file);
-                    *dataSize = count;
-
-                    if (count != size) TRACELOG(LOG_WARNING, "FILEIO: [%s] File partially loaded", fileName);
-                    else TRACELOG(LOG_INFO, "FILEIO: [%s] File loaded successfully", fileName);
+                    size_t count = fread(data, sizeof(unsigned char), size, file);
+                    
+                    // WARNING: fread() returns a size_t value, usually 'unsigned int' (32bit compilation) and 'unsigned long long' (64bit compilation)
+                    // dataSize is unified along raylib as a 'int' type, so, for file-sizes > INT_MAX (2147483647 bytes) we have a limitation
+                    if (count > 2147483647)
+                    {
+                        TRACELOG(LOG_WARNING, "FILEIO: [%s] File is bigger than 2147483647 bytes, avoid using LoadFileData()", fileName);
+                        
+                        RL_FREE(data);
+                        data = NULL;
+                    }
+                    else
+                    {
+                        *dataSize = (int)count;
+
+                        if ((*dataSize) != size) TRACELOG(LOG_WARNING, "FILEIO: [%s] File partially loaded (%i bytes out of %i)", fileName, dataSize, count);
+                        else TRACELOG(LOG_INFO, "FILEIO: [%s] File loaded successfully", fileName);
+                    }
                 }
                 else TRACELOG(LOG_WARNING, "FILEIO: [%s] Failed to allocated memory for file reading", fileName);
             }
@@ -254,7 +267,9 @@ bool SaveFileData(const char *fileName, void *data, int dataSize)
 
         if (file != NULL)
         {
-            unsigned int count = (unsigned int)fwrite(data, sizeof(unsigned char), dataSize, file);
+            // WARNING: fwrite() returns a size_t value, usually 'unsigned int' (32bit compilation) and 'unsigned long long' (64bit compilation)
+            // and expects a size_t input value but as dataSize is limited to INT_MAX (2147483647 bytes), there shouldn't be a problem
+            int count = (int)fwrite(data, sizeof(unsigned char), dataSize, file);
 
             if (count == 0) TRACELOG(LOG_WARNING, "FILEIO: [%s] Failed to write file", fileName);
             else if (count != dataSize) TRACELOG(LOG_WARNING, "FILEIO: [%s] File partially written", fileName);