[Pydns-developer] [ pydns-Bugs-954095 ] Bug in DNS.Lib.Unpacker.getbyte()

[SourceForge.net <no...@so...>]

Bugs item #954095, was opened at 2004-05-14 13:16
Message generated for change (Comment added) made by kitterma
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=403045&aid=954095&group_id=31674

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Jon Ribbens (jribbens)
Assigned to: Nobody/Anonymous (nobody)
Summary: Bug in DNS.Lib.Unpacker.getbyte()

Initial Comment:
In Lib.py, the line in getbyte():

        if self.offset > len(self.buf):

should be:

        if self.offset >= len(self.buf):


----------------------------------------------------------------------

Comment By: Scott Kitterman (kitterma)
Date: 2007-11-18 21:41

Message:
Logged In: YES 
user_id=1300068
Originator: NO

Fixed in 2.3.1

----------------------------------------------------------------------

Comment By: Scott Kitterman (kitterma)
Date: 2007-02-16 08:51

Message:
Logged In: YES 
user_id=1300068
Originator: NO

A fix for this issue has been included in the latest python-dns update in
Ubuntu Linux.  See
https://launchpad.net/ubuntu/+source/python-dns/2.3.0-5.1ubuntu2 for
details.

----------------------------------------------------------------------

Comment By: Scott Kitterman (kitterma)
Date: 2007-01-25 17:10

Message:
Logged In: YES 
user_id=1300068
Originator: NO

Thanks.  I know it's been a long time.  I patched pydns for a small bug
that got me and packaged it for Ubuntu, so for the moment I'm inspired to
try and tackle the rest.

Scott K

----------------------------------------------------------------------

Comment By: Jon Ribbens (jribbens)
Date: 2007-01-25 16:16

Message:
Logged In: YES 
user_id=76089
Originator: YES

Sorry, 2.5 years later I can't remember the specific circumstances. I
assume it caused a problem with some query or other I was doing.

However, if you examine the code it is easy to verify the bug and fix
without needing to inspect the rest of the program:

        if self.offset > len(self.buf):
            raise UnpackError, "Ran off end of data"
        c = self.buf[self.offset]

If n == len(buf), buf[n] is invalid, so the check should be >= not > .

----------------------------------------------------------------------

Comment By: Scott Kitterman (kitterma)
Date: 2007-01-25 11:54

Message:
Logged In: YES 
user_id=1300068
Originator: NO

Jon,

If you are still interested in pydns...

I am working on fixing bugs in pydns for Ubuntu.  If you could give me a
little more detail on what problems this causes and how to recreate the
problem/verify the fix, I'd be interested in including this.  My hope is to
get all the upstream bugs (plus the Debian/Ubuntu ones I've fixed already)
into an updated package in the next few weeks.

Thanks,

Scott K

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=403045&aid=954095&group_id=31674