malloc(): memory corruption in a weird place - c

Question

I've been dealing with an annoying memory corruption error for a couple of hours. I've checked every related thread here, and I couldn't fix it.
First of all, I'm writing a simple Terminal in C. I'm parsing the commands between pipe (|) and redirection (>, <, etc.) symbols and place them in the queue. Nothing complicated!
Here's the data structure for the queue;
struct command_node {
int index;
char *next_symbol;
struct command_node *nextCommand;
int count;
char **args;
};
When I'm storing small strings in the **args pointer, everything works just fine. However, when one of the arguments is long, I get malloc(): memory corruption error. For example, the following 1st command works fine, the 2nd command causes the error
1st: ls -laF some_folder | wc -l
2nd: ls -laF /home/enesanbar/Application | wc -l
I run the debugger, it showed that the malloc() call for the new node in the queue causes the error.
newPtr = malloc( sizeof(CommandNode) );
I'm carefully allocating the array of strings and freeing after I'm done with them as follows:
char **temp = NULL;
temp = malloc(sizeof(char*) * number_of_args);
/* loop through the argument array */
for (i = 0; i < number_of_args; i++) {
/* ignore the remaining commands after ampersand */
if (strcmp(args[i], "&") == 0) return;
/* split commands by the redirection or pipe symbol */
if (!isSymbol(args[i])) {
temp[count] = malloc(sizeof(strlen(args[i])) + 1);
strcpy(temp[count], args[i]);
count++;
/* if it is the last argument, assign NULL to the symbol in the data structure */
if (i + 1 == number_of_args) {
insertIntoCommands(&headCommand, &tailCommand, temp, NULL, count);
for (j = 0; j < count; j++) free(temp[j]);
count = 0; // reset the counter
}
}
else {
insertIntoCommands(&headCommand, &tailCommand, temp, args[i], count);
for (j = 0; j < count; j++) free(temp[j]);
count = 0; // reset the counter
}
}
I must have missed something, or there's something I don't know about the **args fields and the allocation of the new node although it's nothing I haven't done before.

Answer 1

but how could wrapping a number around the sizeof cause an error in the allocation of a node? I'm just trying to understand out of curiosity.
Like I was saying in my comment, you try to get the size of the pointer inside the strlen function and not the lenght which is provided through the function.
Please take a look at the following:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int main(void){
char *name = "Michi";
size_t length1, length2;
length1 = strlen(name);
length2 = sizeof strlen(name);
printf("Length1 = %zu\n",length1);
printf("Length2 = %zu\n",length2);
return 0;
}
Output:
Length1 = 5
Length2 = 8
One more thing, after you free(temp[j]) don't forget to free(temp) also.
Something like this:
#include <stdio.h>
#include <stdlib.h>
int main(void){
long unsigned int size = 2,i;
char **array;
array = malloc(sizeof(char*) * size * size);
if (array == NULL){
printf("Error, Fix it!\n");
exit(2);
}
for (i = 0; i < size; i++){
array[i] = malloc(sizeof(char*) * 100);
}
/* do code here */
for (i = 0; i < size; i++){
free(array[i]);
}
free(array);
return 0;
}