error, glibc detected - glibc

Question

here is my code:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
main(int argc, char *argv[])
{
struct numbers_struct {
char numbers_array[1000];
};
char Line[300];
FILE *Fp;
int i=0;
long size;
Fp=fopen("input2.txt","r");
fscanf(Fp, "%ld", &size);
struct numbers_struct *numbers = malloc(sizeof(struct numbers_struct) * size);
while(!feof(Fp))
{
if (fgets(Line,1000,Fp)!=NULL)
{
strncpy(numbers[i].numbers_array,Line,1000);
i++;
}
}
int k;
k=i;
for(i=k-1;i>=0;i--)
printf("%s",numbers[i].numbers_array);
free(numbers);
fclose(Fp);
return 0;
}
When I run it, program prints correct output and then this error message:
*** glibc detected *** ./part2: double free or corruption (out): 0x08834170 ***
part2: malloc.c:2451: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd)))) && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)((((__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed.
Aborted (core dumped)
What did I do wrong?

Answer 1

What did I do wrong?
You have corrupted heap.
The best way to diagnose heap corruption are Valgrind and AddressSanitizer. Either of these should point you directly at the problem.
There are two obvious bugs in your program:
fgets(Line,1000,Fp) -- how big is the Line, and how many characters are you reading into it if presented with a long line?
struct numbers_struct *numbers = malloc(sizeof(struct numbers_struct) * size); -- what happens if the input file starts with 3 but contains 15 lines?