Hi Chao,

On 2019/2/18 9:39, Chao Yu wrote:
> If the image is corrupted, qn->name[i] may be anything, as you commented
> above DBG_BUGON(), we really don't need to go through any later codes, it
> can avoid potentially encoutnering wrong condition.
> 
> * otherwise, it will return 1 to just skip the invalid name
> 

Just I commented in the following source code, qn is actually the user requested
name allocated in __d_alloc, which can be guaranteed with the trailing '\0' and
it is a valid string.

Thanks,
Gao Xiang

>>>> +
>>>> +  /* qd could not have trailing '\0' */
>>>> +  /* However it is absolutely safe if < qd->end */
>>>> +  while (qd->name + i < qd->end && qd->name[i] != '\0') {
>>>> +          if (qn->name[i] != qd->name[i]) {
>>>> +                  *matched = i;
>>>> +                  return qn->name[i] > qd->name[i] ? 1 : -1;
>>>>            }
>>>> -          return (qn->len > qd->len);
>>>> +          ++i;
>>>>    }
>>>> -
>>>> -  if (qn->name[i] != qd->name[i]) {
>>>> -          *matched = i;
>>>> -          return qn->name[i] > qd->name[i] ? 1 : -1;
>>>> -  }
>>>> -
>>>> -  ++i;
>>>> -  goto loop;
>>>> +  *matched = i;
>>>> +  /* See comments in __d_alloc on the terminating NUL character */
>>>> +  return qn->name[i] == '\0' ? 0 : 1;
>>>>  }
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