Malformed query causing timeouts due to ignored upstream queries
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
dnsmasq (Ubuntu) |
Expired
|
Undecided
|
Unassigned |
Bug Description
In some situations dnsmasq makes malformed upstream queries resulting in servfail being returned after the 5s timeout built in to dnsmask.
For example asking for
foo
with athing.bar.com and bar.com in the search path and two servers dns1.bar.com and dns1.bar.com results in
System asks both dns1 and dns2 about:
asks dns1 about:
foo. => Servfail;
asks both about:
foo. with what tcpdump transcribes as '[b2&3=0x182] A? => no response from either [5 sec timeout];
retries:
simple "A? foo." query to both, immediate Servfail from both
The query giving the time out appear to be malformed and the upstream servers are completely ignoring it leading to the time out.
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: dnsmasq-base 2.68-1ubuntu0.1
ProcVersionSign
Uname: Linux 3.13.0-77-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
CurrentDesktop: XFCE
Date: Mon Feb 8 15:38:26 2016
InstallationDate: Installed on 2014-05-07 (642 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
SourcePackage: dnsmasq
UpgradeStatus: No upgrade log present (probably fresh install)
Changed in dnsmasq (Ubuntu): | |
status: | New → Incomplete |
This post to the dnsmasq-discuss list: http:// lists.thekelley s.org.uk/ pipermail/ dnsmasq- discuss/ 2015q2/ 009575. html suggests that the bug has been fixed in a later version of dnsmasq and should be fairly easy to backport.