title: AddressSanitizer, What do these terms mean?
body: <p>So I'm using the AddressSanitizer. But it uses some dense terms when describing the problem.</p>
  
  <pre><code>Shadow bytes around the buggy address:
    0x0c067fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0c067fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0c067fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0c067fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0c067fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  =&gt;0x0c067fff8000: fa fa 00 00 00 00[fa]fa 00 00 00 fa fa fa 00 00
    0x0c067fff8010: 00 fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
    0x0c067fff8020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
    0x0c067fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
    0x0c067fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
    0x0c067fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07 
    Heap left redzone:       fa
    Freed heap region:       fd
    Stack left redzone:      f1
    Stack mid redzone:       f2
    Stack right redzone:     f3
    Stack after return:      f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:       f6
    Poisoned by user:        f7
    Container overflow:      fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
  ==7320==ABORTING
  </code></pre>
  
  <p>What does <code>Heap left redzone</code> mean? (and the others but I'm mostly interested in the <code>fa</code> as there is one <code>[fa]</code> which indicates the problem probably?)</p>