Python: Make exception info concept local

This commit is contained in:
Rasmus Lerchedahl Petersen
2021-03-03 16:47:31 +01:00
parent 4196dc2291
commit f02a19669f
12 changed files with 88 additions and 140 deletions

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@@ -293,54 +293,6 @@ module SqlExecution {
}
}
/**
* A data-flow node that carries information about an error. Such information should
* rarely be exposed directly to the user.
*
* Extend this class to refine existing API models. If you want to model new APIs,
* extend `ErrorInfoSource::Range` instead.
*/
class ErrorInfoSource extends DataFlow::Node {
ErrorInfoSource::Range range;
ErrorInfoSource() { this = range }
}
/** Provides a class for modeling new sources of error information, say via APIs. */
module ErrorInfoSource {
/**
* A data-flow node that carries information about an error. Such information should
* rarely be exposed directly to the user.
*
* Extend this class to model new APIs. If you want to refine existing API models,
* extend `ErrorInfoSource` instead.
*/
abstract class Range extends DataFlow::Node { }
}
/**
* A data-flow node that represents the creation or introduction of an exception.
*
* Extend this class to refine existing API models. If you want to model new APIs,
* extend `ExceptionSource::Range` instead.
*/
class ExceptionSource extends ErrorInfoSource::Range {
ExceptionSource::Range range;
ExceptionSource() { this = range }
}
/** Provides a class for modeling new sources of exceptions, say via APIs. */
module ExceptionSource {
/**
* A data-flow node that represents the creation or introduction of an exception.
*
* Extend this class to model new APIs. If you want to refine existing API models,
* extend `ExceptionSource` instead.
*/
abstract class Range extends DataFlow::Node { }
}
/** Provides classes for modeling HTTP-related APIs. */
module HTTP {
import semmle.python.web.HttpConstants

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@@ -1657,33 +1657,6 @@ private module Stdlib {
class Sqlite3 extends PEP249Module {
Sqlite3() { this = sqlite3() }
}
// ---------------------------------------------------------------------------
// traceback
// ---------------------------------------------------------------------------
/** Provides models for the `traceback` module. */
module traceback {
private class TracebackFunctionCall extends ErrorInfoSource::Range, DataFlow::CallCfgNode {
TracebackFunctionCall() {
this =
API::moduleImport("traceback")
.getMember([
"extract_tb", "extract_stack", "format_list", "format_exception_only",
"format_exception", "format_exc", "format_tb", "format_stack"
])
.getACall()
}
}
}
}
private class CaughtException extends ExceptionSource::Range {
CaughtException() { this.asExpr() = any(ExceptStmt s).getName() }
}
/** A call to `sys.exc_info` */
private class SysExcInfoCall extends ErrorInfoSource::Range, DataFlow::CallCfgNode {
SysExcInfoCall() { this = API::moduleImport("sys").getMember("exc_info").getACall() }
}
// ---------------------------------------------------------------------------

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@@ -0,0 +1,34 @@
/** Provides classes representing various sources of information about raised exceptions. */
import python
import semmle.python.dataflow.new.DataFlow
private import semmle.python.ApiGraphs
/**
* A data-flow node that carries information about a raised exception.
* Such information should rarely be exposed directly to the user.
*/
abstract class ExceptionInfo extends DataFlow::Node { }
/** A call to a function from the `traceback` module revealing information about a raised exception. */
private class TracebackFunctionCall extends ExceptionInfo, DataFlow::CallCfgNode {
TracebackFunctionCall() {
this =
API::moduleImport("traceback")
.getMember([
"extract_tb", "extract_stack", "format_list", "format_exception_only",
"format_exception", "format_exc", "format_tb", "format_stack"
])
.getACall()
}
}
/** A caught exception. */
private class CaughtException extends ExceptionInfo {
CaughtException() { this.asExpr() = any(ExceptStmt s).getName() }
}
/** A call to `sys.exc_info`. */
private class SysExcInfoCall extends ExceptionInfo, DataFlow::CallCfgNode {
SysExcInfoCall() { this = API::moduleImport("sys").getMember("exc_info").getACall() }
}

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@@ -7,6 +7,7 @@ import python
import semmle.python.dataflow.new.DataFlow
import semmle.python.dataflow.new.TaintTracking
import semmle.python.Concepts
private import ExceptionInfo
/**
* A taint-tracking configuration for detecting stack trace exposure.
@@ -14,7 +15,7 @@ import semmle.python.Concepts
class StackTraceExposureConfiguration extends TaintTracking::Configuration {
StackTraceExposureConfiguration() { this = "StackTraceExposureConfiguration" }
override predicate isSource(DataFlow::Node source) { source instanceof ErrorInfoSource }
override predicate isSource(DataFlow::Node source) { source instanceof ExceptionInfo }
override predicate isSink(DataFlow::Node sink) {
sink = any(HTTP::Server::HttpResponse response).getBody()