Wireshark · Ethereal-dev: Re: [Ethereal-dev] Re: packet-pgsql.c changes in 0.10.9

[Guy Harris <gharris@xxxxxxxxx>]

Abhijit Menon-Sen wrote:

>     guint32 l = tvb_get_ntohl( ... );
>
>     if ( l > 0 && l < 1000000 )
>         ...
>     n += l;
>
> And that last increment should be done only if l > 0.

If l is 0, "n += l" isn't a problem; the only problem is if l >= 1000000.

The right fix for that is to get rid of the test against 1000000, and 
to, instead, use "tvb_ensure_bytes_exist()" before dissecting - 
"tvb_ensure_bytes_exist()" doesn't give a special meaning to a negative 
length, it just assumes that a negative length really means "very large 
positive length" and throws the appropriate exception.

I've checked in a change to do that.