#3 Bug in DNS.Lib.Unpacker.getbyte()

[Jon Ribbens]

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

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

should be:

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

[Scott Kitterman]

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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

[Jon Ribbens]

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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 > .

[Scott Kitterman]

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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

[Scott Kitterman]

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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.

[Scott Kitterman]

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Fixed in 2.3.1

[Scott Kitterman]

This is fixed in the latest pydns and py3dns.