Still a problem in 3.13.0-39 and 3.13.0-40.47 BUT... I've found a workaround. First of all, this is a bug in the KERNEL. It's messing up setuid. This has been FIXED in various other lines of the kernel which is where my workaround comes from.
First- don't settle for a workaround. Log into Ubuntu's launchpad and add your voice. If the developers don't know it's not affecting lots of people it won't get much attention. The bugs to comment on are here:
- https://bugs.launchpad.net/ubuntu/+source/linux-lts-quantal/+bug/1269053 (this is the one that was fixed)
- https://bugs.launchpad.net/ubuntu/+source/linux-lts-trusty/+bug/1335478 (this is the open bug)
Next, this is the workaround I figured out for Ubuntu 14.04.1 LTS (Trusty Tahr). Until Trusty's kernels get fixed, use the working Ubuntu 12.04 Precise Pangolin kernels, which include the 3.2.0 and the 3.5.0 varieties.
1. sudo echo 'APT::Default-Release "trusty";' >> /etc/apt/apt.conf.d/01ubuntu
(This will make sure if the Trusty repositories have a package or update, you will get it from there.)
2. sudo echo 'deb http://security.ubuntu.com/ubuntu precise-security main' >> /etc/apt/sources.list
(This adds the Precise repositories as an option for apt.)
3. Search for the latest kernel security release for the 3.2 or 3.5 line:
#apt-cache search linux-image-3.5 -or- #apt-cache search linux-image-3.2
4. Install the desired kernel and headers:
#apt-get install linux-image-3.5.0-54-generic linux-headers-3.5.0-54-generic
(these are just examples- use the actual version number of the kernel and header packages you want from your apt-cache search.)
5. Make sure there is not any newer kernel by apt-get remove, or specify the kernel you want to boot to in /etc/default/grub (see this article for details).
6. Reboot. Test.
7. If you're still getting the same error, it's probably not for the same reason and you didn't need to do any of this stuff. You may be dealing with another service like postfix, apache, or samba stealing your ports. See this article about that.