I've come across a weird issue where I receive a segmentation fault when trying to close the file. Data is being written to the file correctly, could there be some sort of race condition happening between fflush and fclose?

//main.c

#define filename "/home/test.txt";
char fbuf[255];
sprintf(fbuf, "%s, %f, %f,%f \n", "big", 8.0,0.0,0.8);

sendFile(&fbuf, sizeof(fbuf), (void *)filename);

static void
sendFile( void *data, int size, char *pName)
{
    FILE *pFile = fopen(pName,"a");
    char *buf = NULL;
    buf = (char *)malloc(255);
    memcpy(buf, data, sizeof(char *)*size);

    if(pFile == NULL) {
        logger(LOG_INFO, "Error opening file\n");
}
    else {
        fwrite(buf, 1, strlen(buf), pFile);
        fflush(pFile);
        fclose(pFile);
    }
    free (buf);
}

Any help or suggestions are greatly appreciated.

I think the problem is in memcpy(buf, data, sizeof(char *)*size).

Shouldn't it be simply memcpy(buf, data, size)?

Looking at your example, fbuf (i.e. data) is 255 chars, and buf is 255 chars as well. But the memcpy is copying more than one thousand chars effectively writing garbage into the heap, with unpredictable results.