kernel security test report that the lttng_probe_writeback module is tainted on Bionic s390x

[Po-Hsu Lin]

This issue was only spotted on Bionic s390x instances.

  FAIL: test_140_kernel_modules_not_tainted (__main__.KernelSecurityTest)
  kernel modules are not marked with a taint flag (especially 'E' for TAINT_UNSIGNED_MODULE)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "./test-kernel-security.py", line 1727, in test_140_kernel_modules_not_tainted
      self.fail('Module \'%s\' is tainted: %s' % (fields[0], last_field))
  AssertionError: Module 'lttng_probe_writeback' is tainted: (OE)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-10-generic 4.15.0-10.11
ProcVersionSignature: Ubuntu 4.15.0-10.11-generic 4.15.3
Uname: Linux 4.15.0-10-generic s390x
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access '/dev/snd/': No such file or directory
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay': 'aplay'
ApportVersion: 2.20.8-0ubuntu10
Architecture: s390x
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord': 'arecord'
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
CurrentDmesg:

Date: Fri Feb 23 07:43:00 2018
HibernationDevice: RESUME=UUID=caaee9b2-6bc1-4c8e-b26c-69038c092091
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig': 'iwconfig'
Lspci:

Lsusb: Error: command ['lsusb'] failed with exit code 1:
PciMultimedia:

ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C
 SHELL=/bin/bash
ProcFB: Error: [Errno 2] No such file or directory: '/proc/fb'
ProcKernelCmdLine: root=UUID=c7d7bbcb-a039-4ead-abfe-7672dea0add4 crashkernel=196M
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-10-generic N/A
 linux-backports-modules-4.15.0-10-generic N/A
 linux-firmware 1.171
RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1751213

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Colin Ian King (colin-king)]

Can you add some explanation on how to reproduce this issue, I have no idea of how the test was run. Thanks!

[Po-Hsu Lin (cypressyew)]

Hi,

steps here:
 git clone --depth 1 https://git.launchpad.net/qa-regression-testing
 cd qa-regression-testing/scripts
 sudo python ./test-kernel-security.py -v

Thanks

[Po-Hsu Lin (cypressyew)]

BTW you will need to install these package first
git build-essential libcap2-bin gawk execstack exim4 libcap-dev libkeyutils-dev

And enable deb-src in the source list

[Po-Hsu Lin (cypressyew)]

Hi Colin,
did you successfully have this issue reproduced on your side?

[Po-Hsu Lin (cypressyew)]

This issue was only spotted on s390x, because the s390x instance won't get re-deployed.
So the module inserted by the lttng test will stay there, and caught by this security test.

[Colin Ian King (colin-king)]

That makes sense. We need to force remove that module then.

[Po-Hsu Lin (cypressyew)]

Fixed by removing the module in the end.
http://kernel.ubuntu.com/git/ubuntu/autotest-client-tests.git/commit/?h=master-next&id=8b193fcf0bd2d74d9b1846768554eeb0ef0c7c4d