Question

Below is a small portion of the source code where fclose is causing error? This function is not called always, at some particular condition this function is called.

int write_into_file (char * file_name)
{       
    FILE * fp = NULL ;

    if (file_name == NULL)
    {   
        return FAIL ; 
    }   

    if ((fp = fopen (file_name , "r")) == NULL)
    {   
        if ((fp = fopen (file_name, "w")) == NULL)
        {
            return FAIL ;
        }
    }
    fclose (fp) ;
    fp = NULL ;

    return SUCESS;

}

We are passing character buffer of size 1024 to file_name.
Please can anyone tell me why fclose causes segmentation fault?

Answer 1

I see no possible way that fclose could be causing a segfault here, I think your problem lies somewhere else in the program.

It might be possible that the stack got corrupted elsewhere, and that the bug shows when fclose gets called. I suggest you to review your other source code once more, and step over it with a debugger/memory analyzer closely watching what happens.

The only other thing I can see that might cause a bug is file_name not being null-terminated.