Re: Code quality issues in ICU patch

On 6/23/17 12:31, Tom Lane wrote:
> icu_to_uchar() and icu_from_uchar(), and perhaps other places, are
> touchingly naive about integer overflow hazards in buffer size
> calculations. I call particular attention to this bit in
> icu_from_uchar():
>
> len_result = UCNV_GET_MAX_BYTES_FOR_STRING(len_uchar, ucnv_getMaxCharSize(icu_converter));
>
> The ICU man pages say that that macro is defined as
>
> #define UCNV_GET_MAX_BYTES_FOR_STRING(length, maxCharSize) (((int32_t)(length)+10)*(int32_t)(maxCharSize))
>
> which means that getting this to overflow (resulting in
> probably-exploitable memory overruns) would be about as hard as taking
> candy from a baby.

Here is a patch that should address this.

(I don't think the overruns were exploitable. You'd just get a buffer
overflow error from the ucnv_* function.)

--
Peter Eisentraut http://www.2ndQuadrant.com/
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