Segmentation Fault When Modifying Structs in a Linked List with Pointers in C
I'm getting frustrated with I'm getting frustrated with After trying multiple solutions online, I still can't figure this out. I've looked through the documentation and I'm still confused about I'm sure I'm missing something obvious here, but I'm working with a segmentation fault when I try to modify elements of a linked list that I defined using structs in C. I've carefully set up the linked list and created a function to update the values, but when I run the code, it crashes unexpectedly. Here's a snippet of the struct definition and the linked list creation: ```c typedef struct Node { int data; struct Node* next; } Node; Node* createNode(int value) { Node* newNode = (Node*)malloc(sizeof(Node)); if (!newNode) { fprintf(stderr, "Memory allocation failed\n"); exit(EXIT_FAILURE); } newNode->data = value; newNode->next = NULL; return newNode; } Node* head = NULL; head = createNode(1); head->next = createNode(2); head->next->next = createNode(3); ``` After creating the linked list, I created a function to modify the data of a specific node: ```c void updateNode(Node* node, int newValue) { if (node == NULL) { fprintf(stderr, "Attempt to update a NULL node\n"); return; } node->data = newValue; } ``` When I call `updateNode(head->next, 5);`, the program crashes with a segmentation fault. I've tried checking if the node is NULL before modifying it, and I ensured that the list creation is correct. I also verified that I am indeed passing the right node, but the scenario continues. I suspect it might be something related to pointer dereferencing or memory access, but I'm not sure what I might be missing. I've also tried running the code through Valgrind, and it indicates an invalid write operation, but doesn't provide much clarity on where it occurs. Can anyone help identify what might be going wrong here? Any help would be greatly appreciated! I'm working on a web app that needs to handle this. I'm working on a service that needs to handle this. Thanks in advance! For reference, this is a production desktop app. Any advice would be much appreciated. What would be the recommended way to handle this?