Add test for loading corrupted metadata

Signed-off-by: Katarzyna Treder <katarzyna.treder@h-partners.com>

test/functional/tests/security/test_load_corrupted_metadata.py

@@ -0,0 +1,149 @@
+#
+# Copyright(c) 2021 Intel Corporation
+# Copyright(c) 2023-2024 Huawei Technologies Co., Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import pytest
+import random
+
+from api.cas import casadm
+from api.cas.cache_config import (
+    CacheMode,
+    CacheLineSize,
+    CleaningPolicy,
+    PromotionPolicy,
+    SeqCutOffPolicy,
+)
+from storage_devices.device import Device
+from core.test_run import TestRun
+from test_tools.dd import Dd
+from test_tools.fs_utils import remove
+from test_utils.filesystem.symlink import Symlink
+from test_utils.os_utils import load_kernel_module, unload_kernel_module, is_kernel_module_loaded
+from test_utils.output import CmdException
+from test_utils.size import Size, Unit
+
+
+@pytest.mark.parametrizex("cache_mode", CacheMode)
+@pytest.mark.parametrizex("cache_line_size", CacheLineSize)
+@pytest.mark.parametrizex("cleaning_policy", CleaningPolicy)
+@pytest.mark.parametrizex("promotion_policy", PromotionPolicy)
+@pytest.mark.parametrizex("seq_cutoff_policy", SeqCutOffPolicy)
+def test_load_corrupted_metadata(cache_mode, cache_line_size, cleaning_policy,
+                                 promotion_policy, seq_cutoff_policy):
+    """
+        title: Security test for loading cache with corrupted metadata.
+        description: |
+          Validate the ability of Open CAS to load cache instance and work if metadata is corrupted.
+        pass_criteria:
+          - If metadata is recognized as corrupted, load operation should be aborted.
+          - If not then executing I/O operations on CAS device should not result in kernel panic.
+    """
+
+    module = "brd"
+    iteration_per_config = 1000
+
+    with TestRun.step("Prepare RAM devices for test."):
+        load_kernel_module(
+            module, {
+                "rd_nr": 2,
+                "rd_size": int(Size(100, Unit.MiB).get_value(Unit.KiB))
+            }
+        )
+        if not is_kernel_module_loaded(module):
+            TestRun.fail(f"Cannot load '{module}' module. Module is unsupported.")
+
+        cache_dev_link = Symlink.get_symlink(
+            link_path="/dev/disk/by-id/cache_dev",
+            target="/dev/ram0",
+            create=True
+        )
+        core_dev_link = Symlink.get_symlink(
+            link_path="/dev/disk/by-id/core_dev",
+            target="/dev/ram1",
+            create=True
+        )
+
+        cache_dev = Device(cache_dev_link.full_path)
+        core_dev = Device(core_dev_link.full_path)
+
+    for iteration in TestRun.iteration(
+            range(iteration_per_config),
+            f"Corrupt metadata {iteration_per_config} times."
+    ):
+
+        with TestRun.step("Prepare cache and core."):
+            cache = casadm.start_cache(cache_dev, cache_mode, cache_line_size, force=True)
+            core = casadm.add_core(cache, core_dev)
+            metadata_size = int(cache.metadata_size_on_disk.get_value())
+
+        with TestRun.step("Configure cache."):
+            cache.set_cleaning_policy(cleaning_policy)
+            cache.set_promotion_policy(promotion_policy)
+            cache.set_seq_cutoff_policy(seq_cutoff_policy)
+
+        with TestRun.step("Fill cache with random data."):
+            Dd().input('/dev/urandom') \
+                .output(core.path) \
+                .block_size(Size(1, Unit.Blocks512)) \
+                .oflag('direct') \
+                .run()
+
+        with TestRun.step("Stop cache without flush."):
+            cache.stop(True)
+
+        with TestRun.step("Corrupt metadata."):
+            corrupt_metadata(cache_dev, iteration, metadata_size)
+
+        with TestRun.step("Try to load cache."):
+            loaded = False
+            try:
+                casadm.load_cache(cache_dev)
+                loaded = True
+                TestRun.LOGGER.info("Cache is loaded.")
+            except CmdException:
+                TestRun.LOGGER.info("Cache is not loaded.")
+
+        if loaded:
+            with TestRun.step("Run random I/O traffic to cache."):
+                try:
+                    Dd().input('/dev/urandom') \
+                        .output(core.path) \
+                        .block_size(Size(1, Unit.Blocks512)) \
+                        .oflag('direct') \
+                        .run()
+                except CmdException:
+                    TestRun.LOGGER.error("Sending I/O requests to cache caused error.")
+                    cache.stop()
+                    break
+
+            with TestRun.step("Stop cache."):
+                cache.stop()
+
+    with TestRun.step("Delete symlinks and unload 'brd' module."):
+        remove(cache_dev.path, True)
+        remove(core_dev.path, True)
+        unload_kernel_module('brd')
+
+
+def corrupt_metadata(cache_dev: Device, iteration: int, metadata_size: int):
+    superblock_max_bytes = int(Size(8, Unit.KiB).get_value())
+    number_of_bits_to_corrupt = random.randint(1, 10)
+    corrupted_bytes = []
+    for i in range(number_of_bits_to_corrupt):
+        random_mask = 1 << random.randrange(0, 7)
+        random_offset = random.randrange(
+            0, superblock_max_bytes if iteration % 100 == 0 else metadata_size
+        )
+        corrupted_bytes.append(random_offset)
+        corrupt_bits(cache_dev, random_mask, random_offset)
+    corrupted_bytes.sort()
+    TestRun.LOGGER.info(f"Corrupted bytes: {corrupted_bytes}")
+
+
+def corrupt_bits(cache_dev: Device, mask: int, offset: int):
+    output = TestRun.executor.run(f"xxd -bits -len 1 -seek {offset} -postscript {cache_dev.path}")
+    corrupt_cmd = f"printf '%02x' $((0x{output.stdout}^{mask}))"
+    corrupt_cmd = f"{corrupt_cmd} | xxd -revert -postscript -seek {offset} - {cache_dev.path}"
+    TestRun.executor.run_expect_success(corrupt_cmd)