canonical-ubuntu-qa team mailing list archive

[Koichiro Den <2083819@xxxxxxxxxxxxxxxxxx>]

Oracular ships systemd 256 and /tmp/ is now by default a tmpfs. [1]

  On Oracular:
    $ findmnt --target /tmp/
    TARGET SOURCE FSTYPE OPTIONS
    /tmp   tmpfs  tmpfs  rw,nosuid,nodev,size=6123876k,nr_inodes=1048576,inode64
  On Noble:
    $ findmnt --target /tmp
    TARGET
      SOURCE    FSTYPE OPTIONS
    / /dev/vda1 ext4   rw,relatime,discard,errors=remount-ro,commit=30

test_032_dev_kmem runs mknod(2) to create a character device file under /tmp.
Because of the difference, on Oracular, openat(2) (by errno-read.py) returns earlier with errno 13 (Permission denied), while errno 6 (No such device) is expected.

-> vfs_open()
   [...]
   -> may_open()
     -> may_open_dev() returns 0 because of MNT_NODEV
        return -EACCES

The whole point of test_032_dev_kmem is I think to test ubuntu policy
(CONFIG_DEVKMEM=n for many years before bbcd53c96071 ("drivers/char:
remove /dev/kmem for good")):

-> vfs_open()
   [...]
   -> chrdev_open()
     -> memory_open()
       -> devlist[2 /*kmem*/] is empty so return -ENXIO

I'll propose an update (fix) for test_032_dev_kmem to qa-regression-testing.
                                                                                                                                                                                                                                                                                                                                                                                              
[1] https://git.launchpad.net/ubuntu/+source/systemd/tree/debian/NEWS?h=ce0abd32d7d3a&id=ce0abd32d7d3a920a7728a21a1977749db2e3776

-- 
You received this bug notification because you are a member of Canonical
Platform QA Team, which is subscribed to ubuntu-kernel-tests.
https://bugs.launchpad.net/bugs/2083819

Title:
  test_032_dev_kmem from ubuntu_qrt_kernel_security failed on Oracular
  (Permission denied)

Status in ubuntu-kernel-tests:
  New

Bug description:
  Issue found on Openstack amd64/arm64/ppc64el with Oracular since
  6.11.0-5.5 in d2024.08.12.

  It's worthy to note that with 6.11.0-4.4, only ARM64 has failed with
  this test, AMD64 and PPC64EL are good.

  The test is expecting return code 6 (No such device), but we got 13
  (Permission denied) here on Oracular.

  Test log:
   Running 'python3 ./test-kernel-security.py -v KernelSecurityTest.test_032_dev_kmem'
   Running test: './test-kernel-security.py' distro: 'Ubuntu 24.10' kernel: '6.11.0-8.8 (Ubuntu 6.11.0-8.8-generic 6.11.0)' arch: 'amd64' init: 'systemd' uid: 0/0 SUDO_USER: 'ubuntu')
   test_032_dev_kmem (__main__.KernelSecurityTest.test_032_dev_kmem)
   /dev/kmem not available ... FAIL

   ======================================================================
   FAIL: test_032_dev_kmem (__main__.KernelSecurityTest.test_032_dev_kmem)
   /dev/kmem not available
   ----------------------------------------------------------------------
   Traceback (most recent call last):
     File "/home/ubuntu/autotest/client/tmp/ubuntu_qrt_kernel_security/src/qa-regression-testing/scripts/./test-kernel-security.py", line 375, in test_032_dev_kmem
       self.assertShellExitEquals(expected, ["./errno-read.py", kmem, '4096'])
     File "/home/ubuntu/autotest/client/tmp/ubuntu_qrt_kernel_security/src/qa-regression-testing/scripts/testlib.py", line 1332, in assertShellExitEquals
       self.assertEqual(expected, rc, msg + result + report)
   AssertionError: 6 != 13 : Got exit code 13, expected 6
   Command: './errno-read.py', '/tmp/kmem-y9brst6e/kmem', '4096'
   Output:
   /tmp/kmem-y9brst6e/kmem: Permission denied

   ----------------------------------------------------------------------
   Ran 1 test in 0.046s

   FAILED (failures=1)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/2083819/+subscriptions