👀 Views: 65 💬 Answers: 1 📅 Created: 2025-06-11

c memory-management dynamic-memory C

I recently switched to I'm working on a project and hit a roadblock. I'm currently working with an scenario with dynamically allocating a 2D array in C. I have implemented a function to allocate memory for a matrix based on user input, but I'm working with memory corruption errors when I try to access the elements. Here’s the code I used to allocate and initialize the array: ```c #include <stdio.h> #include <stdlib.h> int** allocateMatrix(int rows, int cols) { int** matrix = malloc(rows * sizeof(int*)); if (matrix == NULL) return NULL; for (int i = 0; i < rows; i++) { matrix[i] = malloc(cols * sizeof(int)); if (matrix[i] == NULL) { for (int j = 0; j < i; j++) { free(matrix[j]); } free(matrix); return NULL; } } return matrix; } int main() { int rows = 3, cols = 4; int** myMatrix = allocateMatrix(rows, cols); if (myMatrix == NULL) { printf("Memory allocation failed.\n"); return 1; } for (int i = 0; i <= rows; i++) { // Intentional off-by-one behavior here for (int j = 0; j < cols; j++) { myMatrix[i][j] = i * j; } } // Free memory here for (int i = 0; i < rows; i++) { free(myMatrix[i]); } free(myMatrix); return 0; } ``` When I run this code, I get a segmentation fault or sometimes a memory corruption behavior when accessing `myMatrix[i][j]` in the nested loop. I suspect it might be due to the incorrect loop bounds, since I'm iterating from `0` to `rows`, which includes an out-of-bounds access. I've tried adjusting the loop limits but I'm not sure how to correctly implement this. Any suggestions on how to avoid these errors? Also, I would appreciate any best practices for handling dynamic memory in C, especially for multi-dimensional arrays. Is there a better approach? This issue appeared after updating to C 3.11. Thanks for taking the time to read this!