[PATCH v2 0/2] tests/functional: protect cached assets from modification

[PATCH v2 0/2] tests/functional: protect cached assets from modification

[Daniel P. Berrangé]

Changed in v2:

 * Make tuxrun tests actually work

Daniel P. Berrangé (2):
  tests/functional: make tuxrun disk images writable
  tests/functional: make cached asset files read-only

 tests/functional/qemu_test/asset.py      |  3 +++
 tests/functional/qemu_test/tuxruntest.py | 10 ++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

-- 
2.46.0

[PATCH v2 1/2] tests/functional: make tuxrun disk images writable

[Daniel P. Berrangé]

The zstd command will preserve the input archive permissions on the
output file. So when we decompress the readonly cached image, the
resulting per-test run private disk image will also be readonly.
We need it to be writable, so make it so.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 tests/functional/qemu_test/tuxruntest.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/tests/functional/qemu_test/tuxruntest.py b/tests/functional/qemu_test/tuxruntest.py
index 904da6f609..f05aa96ad7 100644
--- a/tests/functional/qemu_test/tuxruntest.py
+++ b/tests/functional/qemu_test/tuxruntest.py
@@ -10,6 +10,7 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
 import os
+import stat
 import time
 
 from qemu_test import QemuSystemTest
@@ -77,12 +78,17 @@ def fetch_tuxrun_assets(self, kernel_asset, rootfs_asset, dtb_asset=None):
         kernel_image =  kernel_asset.fetch()
         disk_image_zst = rootfs_asset.fetch()
 
+        disk_image = self.workdir + "/rootfs.ext4"
+
         run_cmd([self.zstd, "-f", "-d", disk_image_zst,
-                 "-o", self.workdir + "/rootfs.ext4"])
+                 "-o", disk_image])
+        # zstd copies source archive permissions for the output
+        # file, so must make this writable for QEMU
+        os.chmod(disk_image, stat.S_IRUSR | stat.S_IWUSR)
 
         dtb = dtb_asset.fetch() if dtb_asset is not None else None
 
-        return (kernel_image, self.workdir + "/rootfs.ext4", dtb)
+        return (kernel_image, disk_image, dtb)
 
     def prepare_run(self, kernel, disk, drive, dtb=None, console_index=0):
         """
-- 
2.46.0

[PATCH v2 2/2] tests/functional: make cached asset files read-only

[Daniel P. Berrangé]

This ensures that if a functional test runs QEMU with a writable
disk pointing to a cached asset, an error will be reported, rather
than silently modifying the cache file.

As an example, tweaking test_sbsaref.py to set snapshot=off,
results in a clear error:

  Command: ./build/qemu-system-aarch64 ...snip... -drive file=/var/home/berrange/.cache/qemu/download/44cdbae275ef1bb6dab1d5fbb59473d4f741e1c8ea8a80fd9e906b531d6ad461,format=raw,snapshot=off -cpu max,pauth=off
  Output: qemu-system-aarch64: Could not open '/var/home/berrange/.cache/qemu/download/44cdbae275ef1bb6dab1d5fbb59473d4f741e1c8ea8a80fd9e906b531d6ad461': Permission denied

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 tests/functional/qemu_test/asset.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/functional/qemu_test/asset.py b/tests/functional/qemu_test/asset.py
index e47bfac035..f126cd5863 100644
--- a/tests/functional/qemu_test/asset.py
+++ b/tests/functional/qemu_test/asset.py
@@ -8,6 +8,7 @@
 import hashlib
 import logging
 import os
+import stat
 import subprocess
 import sys
 import unittest
@@ -143,6 +144,8 @@ def fetch(self):
             raise Exception("Hash of %s does not match %s" %
                             (self.url, self.hash))
         tmp_cache_file.replace(self.cache_file)
+        # Remove write perms to stop tests accidentally modifying them
+        os.chmod(self.cache_file, stat.S_IRUSR | stat.S_IRGRP)
 
         self.log.info("Cached %s at %s" % (self.url, self.cache_file))
         return str(self.cache_file)
-- 
2.46.0

Re: [PATCH v2 1/2] tests/functional: make tuxrun disk images writable

[Thomas Huth]

On 25/10/2024 11.26, Daniel P. Berrangé wrote:
> The zstd command will preserve the input archive permissions on the
> output file. So when we decompress the readonly cached image, the
> resulting per-test run private disk image will also be readonly.
> We need it to be writable, so make it so.
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>   tests/functional/qemu_test/tuxruntest.py | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)

Ah, so it was just about the new tuxrun tests that were likely not merged 
before ... Good to know that we can fix it in a central spot :-)

Reviewed-by: Thomas Huth <thuth@redhat.com>