algorithm - Use of uninitialised value of size 8 when use malloc in c -

i have code implements b+ tree. order 3

the problem if insert third value in tree ( leaf split ) throws me segmentation fault @ line

temp_pointers = (void**) malloc(order * sizeof(void *)); 

here full code leaf split

node * split_leaf_and_insert(node * root, node * leaf, char* key,         record * pointer) {     node * new_leaf = null;     char ** temp_keys = null;     void ** temp_pointers = null;     int insertion_index, split, i, j;     char*new_key;     new_leaf = create_leaf();     temp_keys = (char**) malloc(order * sizeof(char*));     if (temp_keys == null) {         exit(exit_failure);     }     temp_pointers = (void**) malloc(order * sizeof(void *));     if (temp_pointers == null) {         exit(exit_failure);     }     insertion_index = 0;     while (insertion_index < order - 1 && leaf->keys[insertion_index] < key) {         insertion_index++;     }     (i = 0, j = 0; < leaf->number_of_keys; i++, j++) {         if (j == insertion_index) {             j++;         }         temp_keys[j] = (char*) malloc(strlen(leaf->keys[i]) + 1);         strcpy(temp_keys[j], leaf->keys[i]);     }     temp_keys[insertion_index] = (char*) malloc(strlen(key) + 1);     strcpy(temp_keys[insertion_index], key);     temp_pointers[insertion_index] = pointer;      leaf->number_of_keys = 0;     split = cut(order - 1);     (i = 0; < split; i++) {         leaf->pointers[i] = temp_pointers[i];         leaf->keys[i] = (char*) malloc((strlen(temp_keys[i]) + 1));         strcpy(leaf->keys[i], temp_keys[i]);         leaf->number_of_keys++;         (i = split, j = 0; < order; i++, j++) {             new_leaf->pointers[j] = temp_pointers[i];             new_leaf->keys[j] = (char*) malloc(strlen(temp_keys[i]) + 1);             strcpy(new_leaf->keys[j], temp_keys[i]);             new_leaf->number_of_keys++;         }         free(temp_pointers);         free(temp_keys);         new_leaf->pointers[order - 1] = leaf->pointers[order - 1];         leaf->pointers[order - 1] = new_leaf;         (i = leaf->number_of_keys; < order - 1; i++) {             leaf->pointers[i] = null;         }         (i = new_leaf->number_of_keys; < order - 1; i++) {             new_leaf->pointers[i] = null;         }         new_leaf->parent = leaf->parent;         new_key = (char*) malloc(strlen(new_leaf->keys[0]) + 1);         strcpy(new_key, new_leaf->keys[0]);     }     return insert_value_into_parent(root, leaf, new_key, new_leaf); } 

like said first 2 records works third says

use of uninitialised value of size 8 when use malloc in c  stack trace ==1336== use of uninitialised value of size 8 ==1336==    @ 0x4041f5: display (b-tree.c:754) ==1336==    0x40519c: main (main.c:54) ==1336==  uninitialised value created heap allocation ==1336==    @ 0x4c2b6cd: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==1336==    0x4036d0: split_leaf_and_insert (b-tree.c:597) ==1336==    0x402e3c: insert_value (b-tree.c:477) ==1336==    0x4029b1: search (b-tree.c:396) ==1336==    0x404159: display (b-tree.c:739) ==1336==    0x40519c: main (main.c:54) ==1336==  ==1336== invalid read of size 8 ==1336==    @ 0x4041f5: display (b-tree.c:754) ==1336==    0x40519c: main (main.c:54) ==1336==  address 0x0 not stack'd, malloc'd or (recently) free'd ==1336==  ==1336==  

the next function insert function calls 1 above

node * insert_value(node * root, char* key, record * rec) {     node * leaf;     if (root == null) {         return create_new_tree(key, rec);     }     leaf = find_leaf(root, key);     if (leaf->number_of_keys < order - 1) {         leaf = insert_value_into_leaf(leaf, key, rec);         return root;     }     return split_leaf_and_insert(root, leaf, key, rec); } 

can explain me happening?