mirror of
https://github.com/volatilityfoundation/volatility3.git
synced 2026-08-29 19:29:42 +02:00
Merge pull request #1842 from SolitudePy/check_idt_malware
Malware categorization: linux.check_idt
This commit is contained in:
ikelos
@@ -38,7 +38,7 @@ For plugin requests, please create an issue with a description of the requested
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linux.bash.Bash Recovers bash command history from memory.
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linux.check_afinfo.Check_afinfo
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linux.check_creds.Check_creds
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linux.check_idt.Check_idt
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linux.malware.check_idt.Check_idt
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.. note:: Here the command is piped to grep and head to provide the start of the list of linux plugins.
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@@ -29,7 +29,7 @@ class TestLinuxPslist:
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class TestLinuxCheckIdt:
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def test_linux_generic_check_idt(self, image, volatility, python):
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rc, out, _err = test_volatility.runvol_plugin(
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"linux.check_idt.Check_idt", image, volatility, python
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"linux.malware.check_idt.Check_idt", image, volatility, python
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)
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assert rc == 0
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@@ -1,168 +1,20 @@
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# This file is Copyright 2020 Volatility Foundation and licensed under the Volatility Software License 1.0
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# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
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#
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import logging
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from typing import List, Optional
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import volatility3.framework.symbols.linux.utilities.modules as linux_utilities_modules
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from volatility3.framework import interfaces, renderers, symbols
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from volatility3.framework.configuration import requirements
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from volatility3.framework.renderers import format_hints
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from volatility3.framework.symbols import linux
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from volatility3.framework import interfaces, deprecation
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from volatility3.plugins.linux.malware import check_idt
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vollog = logging.getLogger(__name__)
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class Check_idt(interfaces.plugins.PluginInterface):
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"""Checks if the IDT has been altered"""
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class Check_idt(
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interfaces.plugins.PluginInterface,
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deprecation.PluginRenameClass,
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replacement_class=check_idt.Check_idt,
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removal_date="2026-06-07",
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):
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"""Checks if the IDT has been altered (deprecated)."""
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_required_framework_version = (2, 0, 0)
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# 2.0.0 - Add versioning at all, add `get_idt_type`
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_version = (2, 0, 0)
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@classmethod
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def get_requirements(cls) -> List[interfaces.configuration.RequirementInterface]:
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return [
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requirements.ModuleRequirement(
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name="kernel",
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description="Linux kernel",
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architectures=["Intel32", "Intel64"],
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),
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requirements.VersionRequirement(
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name="linux_utilities_modules",
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component=linux_utilities_modules.Modules,
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version=(3, 0, 0),
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),
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requirements.VersionRequirement(
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name="linux_utilities_module_gatherers",
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component=linux_utilities_modules.ModuleGatherers,
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version=(1, 0, 0),
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),
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requirements.VersionRequirement(
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name="linuxutils", component=linux.LinuxUtilities, version=(2, 0, 0)
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),
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]
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@staticmethod
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def get_idt_type(context, vmlinux_name) -> Optional[str]:
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"""
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Determines the IDT type for this symbol table or returns None
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The original version ended clauses with an `else` leading to bad fall through
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of returning a type that did not exist in the symbol table.
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Future updates should not leave fall through cases to avoid this repeating.
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"""
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vmlinux = context.modules[vmlinux_name]
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is_32bit = not symbols.symbol_table_is_64bit(context, vmlinux.symbol_table_name)
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# These are in a specific order. Only append to the lists going forward
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# or ask Andrew to run tests before merging.
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if is_32bit:
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idt_types = ["gate_struct", "desc_struct", "gate_struct32"]
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else:
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idt_types = ["gate_struct64", "gate_struct", "idt_desc"]
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for idt_type in idt_types:
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if vmlinux.has_type(idt_type):
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return idt_type
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return None
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def _generator(self):
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idt_type = self.get_idt_type(self.context, self.config["kernel"])
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if not idt_type:
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vollog.error(
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"Unable to determine the data structure type for IDT entries. Please file a bug on the GitHub tracker with your kernel version."
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)
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return
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vmlinux = self.context.modules[self.config["kernel"]]
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known_modules = linux_utilities_modules.Modules.run_modules_scanners(
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context=self.context,
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kernel_module_name=self.config["kernel"],
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caller_wanted_gatherers=linux_utilities_modules.ModuleGatherers.all_gatherers_identifier,
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)
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idt_table_size = 256
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kernel_layer = self.context.layers[vmlinux.layer_name]
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address_mask = kernel_layer.address_mask
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# hw handlers + system call
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check_idxs = list(range(20)) + [128]
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addrs = vmlinux.object_from_symbol("idt_table")
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table = vmlinux.object(
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object_type="array",
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offset=addrs.vol.offset,
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subtype=vmlinux.get_type(idt_type),
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count=idt_table_size,
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absolute=True,
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)
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for i in check_idxs:
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ent = table[i]
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if not ent or not kernel_layer.is_valid(ent.vol.offset):
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continue
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if hasattr(ent, "a"):
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idt_addr = (ent.b & 0xFFFF0000) | (ent.a & 0x0000FFFF)
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else:
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low = ent.offset_low
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middle = ent.offset_middle
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# offset_high is for 64bit systems
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if hasattr(ent, "offset_high"):
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high = ent.offset_high
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else:
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high = 0
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idt_addr = (high << 32) | (middle << 16) | low
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idt_addr = idt_addr & address_mask
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# 0 means unintialized/unused, not a rootkit
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if idt_addr == 0:
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module_name = renderers.NotAvailableValue()
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symbol_name = renderers.NotAvailableValue()
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else:
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module_info, symbol_name = (
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linux_utilities_modules.Modules.module_lookup_by_address(
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self.context, vmlinux.name, known_modules, idt_addr
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)
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)
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if module_info:
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module_name = module_info.name
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else:
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module_name = renderers.NotAvailableValue()
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yield (
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0,
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[
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format_hints.Hex(i),
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format_hints.Hex(idt_addr),
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module_name,
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symbol_name or renderers.NotAvailableValue(),
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],
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)
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def run(self):
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return renderers.TreeGrid(
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[
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("Index", format_hints.Hex),
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("Address", format_hints.Hex),
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("Module", str),
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("Symbol", str),
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],
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self._generator(),
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)
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@@ -0,0 +1,168 @@
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# This file is Copyright 2020 Volatility Foundation and licensed under the Volatility Software License 1.0
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# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
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#
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import logging
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from typing import List, Optional
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import volatility3.framework.symbols.linux.utilities.modules as linux_utilities_modules
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from volatility3.framework import interfaces, renderers, symbols
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from volatility3.framework.configuration import requirements
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from volatility3.framework.renderers import format_hints
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from volatility3.framework.symbols import linux
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vollog = logging.getLogger(__name__)
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class Check_idt(interfaces.plugins.PluginInterface):
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"""Checks if the IDT has been altered"""
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_required_framework_version = (2, 0, 0)
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# 2.0.0 - Add versioning at all, add `get_idt_type`
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_version = (2, 0, 0)
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@classmethod
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def get_requirements(cls) -> List[interfaces.configuration.RequirementInterface]:
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return [
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requirements.ModuleRequirement(
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name="kernel",
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description="Linux kernel",
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architectures=["Intel32", "Intel64"],
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),
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requirements.VersionRequirement(
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name="linux_utilities_modules",
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component=linux_utilities_modules.Modules,
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version=(3, 0, 0),
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),
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requirements.VersionRequirement(
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name="linux_utilities_module_gatherers",
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component=linux_utilities_modules.ModuleGatherers,
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version=(1, 0, 0),
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),
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requirements.VersionRequirement(
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name="linuxutils", component=linux.LinuxUtilities, version=(2, 0, 0)
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),
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]
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@staticmethod
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def get_idt_type(context, vmlinux_name) -> Optional[str]:
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"""
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Determines the IDT type for this symbol table or returns None
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The original version ended clauses with an `else` leading to bad fall through
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of returning a type that did not exist in the symbol table.
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Future updates should not leave fall through cases to avoid this repeating.
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"""
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vmlinux = context.modules[vmlinux_name]
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is_32bit = not symbols.symbol_table_is_64bit(context, vmlinux.symbol_table_name)
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# These are in a specific order. Only append to the lists going forward
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# or ask Andrew to run tests before merging.
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if is_32bit:
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idt_types = ["gate_struct", "desc_struct", "gate_struct32"]
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else:
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idt_types = ["gate_struct64", "gate_struct", "idt_desc"]
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for idt_type in idt_types:
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if vmlinux.has_type(idt_type):
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return idt_type
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return None
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def _generator(self):
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idt_type = self.get_idt_type(self.context, self.config["kernel"])
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if not idt_type:
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vollog.error(
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"Unable to determine the data structure type for IDT entries. Please file a bug on the GitHub tracker with your kernel version."
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)
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return
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vmlinux = self.context.modules[self.config["kernel"]]
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known_modules = linux_utilities_modules.Modules.run_modules_scanners(
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context=self.context,
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kernel_module_name=self.config["kernel"],
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caller_wanted_gatherers=linux_utilities_modules.ModuleGatherers.all_gatherers_identifier,
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)
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idt_table_size = 256
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kernel_layer = self.context.layers[vmlinux.layer_name]
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address_mask = kernel_layer.address_mask
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# hw handlers + system call
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check_idxs = list(range(20)) + [128]
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addrs = vmlinux.object_from_symbol("idt_table")
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table = vmlinux.object(
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object_type="array",
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offset=addrs.vol.offset,
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subtype=vmlinux.get_type(idt_type),
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count=idt_table_size,
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absolute=True,
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)
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for i in check_idxs:
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ent = table[i]
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if not ent or not kernel_layer.is_valid(ent.vol.offset):
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continue
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if hasattr(ent, "a"):
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idt_addr = (ent.b & 0xFFFF0000) | (ent.a & 0x0000FFFF)
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else:
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low = ent.offset_low
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middle = ent.offset_middle
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# offset_high is for 64bit systems
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if hasattr(ent, "offset_high"):
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high = ent.offset_high
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else:
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high = 0
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idt_addr = (high << 32) | (middle << 16) | low
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idt_addr = idt_addr & address_mask
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# 0 means unintialized/unused, not a rootkit
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if idt_addr == 0:
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module_name = renderers.NotAvailableValue()
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symbol_name = renderers.NotAvailableValue()
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else:
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module_info, symbol_name = (
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linux_utilities_modules.Modules.module_lookup_by_address(
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self.context, vmlinux.name, known_modules, idt_addr
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)
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)
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if module_info:
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module_name = module_info.name
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else:
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module_name = renderers.NotAvailableValue()
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yield (
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0,
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[
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format_hints.Hex(i),
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format_hints.Hex(idt_addr),
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module_name,
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symbol_name or renderers.NotAvailableValue(),
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],
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)
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def run(self):
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return renderers.TreeGrid(
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[
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("Index", format_hints.Hex),
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("Address", format_hints.Hex),
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("Module", str),
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("Symbol", str),
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],
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self._generator(),
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)
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