casting something from 1 byte to 8

[stav]

When i build and run this program i get no errors:

#include <stdio.h>
#include <stdlib.h>


struct test
{
	int mytest;
	int myothertest;
};

struct memory
{
	void* mymemory;
};


int main(void)
{

	memory mem;
	mem.mymemory = malloc(1);

	test* testptr = (test*)mem.mymemory;	

	testptr->mytest = 3;
	testptr->myothertest=4;
	
	printf("mytest: %d\nmyothertest: %d\n",testptr->mytest,testptr->myothertest);


	free(mem.mymemory);


	return 0;
}

but since im only allocating 1 byte of memory and casting it to something that is 8 bytes
shouldn't it give me an override memory exception or something?

[keskiverto]

You do write into (and read from) memory that you have not allocated. That is undefined behaviour.

Not crashing is equally undefined as a crash. A crash is much more merciful, for it hints about an issue.