a fast memory leak

leak.c

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


int main(int argc, char *argv[]) {
    size_t i;
    void *mem, *prev;
    mem = NULL;

    for (i = 0; i < SIZE_MAX; i++) {
        if ( (i % 1024) == 0) printf("allocated for %zuM\n", i);
        prev = mem;
        mem = malloc(1048576);
        if (mem == NULL) {
            free(prev);
            printf("Failed allocation at %zuM\n", i);
            return 1;
        }
    }
    return 0;
}