Merge branch 'main' into ts53-ts

Author: erik-krogh

cpp/autobuilder/Semmle.Autobuild.Cpp.Tests/BuildScripts.cs

@@ -145,9 +145,9 @@ IEnumerable<string> IBuildActions.EnumerateDirectories(string dir)
 
         bool IBuildActions.IsMacOs() => IsMacOs;
 
-        public bool IsArm { get; set; }
+        public bool IsRunningOnAppleSilicon { get; set; }
 
-        bool IBuildActions.IsArm() => IsArm;
+        bool IBuildActions.IsRunningOnAppleSilicon() => IsRunningOnAppleSilicon;
 
         string IBuildActions.PathCombine(params string[] parts)
         {

cpp/ql/lib/CHANGELOG.md

@@ -1,3 +1,17 @@
+## 0.12.0
+
+### Breaking Changes
+
+* The expressions `AssignPointerAddExpr` and `AssignPointerSubExpr` are no longer subtypes of `AssignBitwiseOperation`.
+
+### Minor Analysis Improvements
+
+* The "Returning stack-allocated memory" (`cpp/return-stack-allocated-memory`) query now also detects returning stack-allocated memory allocated by calls to `alloca`, `strdupa`, and `strndupa`.
+* Added models for `strlcpy` and `strlcat`.
+* Added models for the `sprintf` variants from the `StrSafe.h` header.
+* Added SQL API models for `ODBC`.
+* Added taint models for `realloc` and related functions.
+
 ## 0.11.0
 
 ### Breaking Changes

cpp/ql/lib/change-notes/2023-10-30-realloc-flow.md

@@ -0,0 +1,13 @@
+## 0.12.0
+
+### Breaking Changes
+
+* The expressions `AssignPointerAddExpr` and `AssignPointerSubExpr` are no longer subtypes of `AssignBitwiseOperation`.
+
+### Minor Analysis Improvements
+
+* The "Returning stack-allocated memory" (`cpp/return-stack-allocated-memory`) query now also detects returning stack-allocated memory allocated by calls to `alloca`, `strdupa`, and `strndupa`.
+* Added models for `strlcpy` and `strlcat`.
+* Added models for the `sprintf` variants from the `StrSafe.h` header.
+* Added SQL API models for `ODBC`.
+* Added taint models for `realloc` and related functions.

cpp/ql/lib/change-notes/2023-10-31-assign-pointer-add-sub-expr.md

@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 0.11.0
+lastReleaseVersion: 0.12.0

cpp/ql/lib/change-notes/released/0.12.0.md

@@ -1,5 +1,5 @@
 name: codeql/cpp-all
-version: 0.11.1-dev
+version: 0.12.1-dev
 groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp

cpp/ql/lib/codeql-pack.release.yml

@@ -31,6 +31,11 @@ abstract class MustFlowConfiguration extends string {
    */
   abstract predicate isSink(Operand sink);
 
+  /**
+   * Holds if data flow through `instr` is prohibited.
+   */
+  predicate isBarrier(Instruction instr) { none() }
+
   /**
    * Holds if the additional flow step from `node1` to `node2` must be taken
    * into account in the analysis.
@@ -48,18 +53,21 @@ abstract class MustFlowConfiguration extends string {
    */
   final predicate hasFlowPath(MustFlowPathNode source, MustFlowPathSink sink) {
     this.isSource(source.getInstruction()) and
-    source.getASuccessor+() = sink
+    source.getASuccessor*() = sink
   }
 }
 
 /** Holds if `node` flows from a source. */
 pragma[nomagic]
 private predicate flowsFromSource(Instruction node, MustFlowConfiguration config) {
-  config.isSource(node)
-  or
-  exists(Instruction mid |
-    step(mid, node, config) and
-    flowsFromSource(mid, pragma[only_bind_into](config))
+  not config.isBarrier(node) and
+  (
+    config.isSource(node)
+    or
+    exists(Instruction mid |
+      step(mid, node, config) and
+      flowsFromSource(mid, pragma[only_bind_into](config))
+    )
   )
 }
 

cpp/ql/lib/qlpack.yml

@@ -81,6 +81,14 @@ class Node0Impl extends TIRDataFlowNode0 {
   /** Gets the operands corresponding to this node, if any. */
   Operand asOperand() { result = this.(OperandNode0).getOperand() }
 
+  /** Gets the location of this node. */
+  final Location getLocation() { result = this.getLocationImpl() }
+
+  /** INTERNAL: Do not use. */
+  Location getLocationImpl() {
+    none() // overridden by subclasses
+  }
+
   /** INTERNAL: Do not use. */
   string toStringImpl() {
     none() // overridden by subclasses
@@ -131,9 +139,15 @@ abstract class InstructionNode0 extends Node0Impl {
   override DataFlowType getType() { result = getInstructionType(instr, _) }
 
   override string toStringImpl() {
-    // This predicate is overridden in subclasses. This default implementation
-    // does not use `Instruction.toString` because that's expensive to compute.
-    result = instr.getOpcode().toString()
+    if instr.(InitializeParameterInstruction).getIRVariable() instanceof IRThisVariable
+    then result = "this"
+    else result = instr.getAst().toString()
+  }
+
+  override Location getLocationImpl() {
+    if exists(instr.getAst().getLocation())
+    then result = instr.getAst().getLocation()
+    else result instanceof UnknownDefaultLocation
   }
 
   final override predicate isGLValue() { exists(getInstructionType(instr, true)) }
@@ -173,7 +187,17 @@ abstract class OperandNode0 extends Node0Impl {
 
   override DataFlowType getType() { result = getOperandType(op, _) }
 
-  override string toStringImpl() { result = op.toString() }
+  override string toStringImpl() {
+    if op.getDef().(InitializeParameterInstruction).getIRVariable() instanceof IRThisVariable
+    then result = "this"
+    else result = op.getDef().getAst().toString()
+  }
+
+  override Location getLocationImpl() {
+    if exists(op.getDef().getAst().getLocation())
+    then result = op.getDef().getAst().getLocation()
+    else result instanceof UnknownDefaultLocation
+  }
 
   final override predicate isGLValue() { exists(getOperandType(op, true)) }
 }
@@ -621,6 +645,24 @@ class GlobalLikeVariable extends Variable {
   }
 }
 
+/**
+ * Returns the smallest indirection for the type `t`.
+ *
+ * For most types this is `1`, but for `ArrayType`s (which are allocated on
+ * the stack) this is `0`
+ */
+int getMinIndirectionsForType(Type t) {
+  if t.getUnspecifiedType() instanceof Cpp::ArrayType then result = 0 else result = 1
+}
+
+private int getMinIndirectionForGlobalUse(Ssa::GlobalUse use) {
+  result = getMinIndirectionsForType(use.getUnspecifiedType())
+}
+
+private int getMinIndirectionForGlobalDef(Ssa::GlobalDef def) {
+  result = getMinIndirectionsForType(def.getUnspecifiedType())
+}
+
 /**
  * Holds if data can flow from `node1` to `node2` in a way that loses the
  * calling context. For example, this would happen with flow through a
@@ -632,20 +674,20 @@ predicate jumpStep(Node n1, Node n2) {
       v = globalUse.getVariable() and
       n1.(FinalGlobalValue).getGlobalUse() = globalUse
     |
-      globalUse.getIndirectionIndex() = 1 and
+      globalUse.getIndirection() = getMinIndirectionForGlobalUse(globalUse) and
       v = n2.asVariable()
       or
-      v = n2.asIndirectVariable(globalUse.getIndirectionIndex())
+      v = n2.asIndirectVariable(globalUse.getIndirection())
     )
     or
     exists(Ssa::GlobalDef globalDef |
       v = globalDef.getVariable() and
       n2.(InitialGlobalValue).getGlobalDef() = globalDef
     |
-      globalDef.getIndirectionIndex() = 1 and
+      globalDef.getIndirection() = getMinIndirectionForGlobalDef(globalDef) and
       v = n1.asVariable()
       or
-      v = n1.asIndirectVariable(globalDef.getIndirectionIndex())
+      v = n1.asIndirectVariable(globalDef.getIndirection())
     )
   )
 }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/MustFlow.qll

@@ -34,7 +34,8 @@ cached
 private newtype TIRDataFlowNode =
   TNode0(Node0Impl node) { DataFlowImplCommon::forceCachingInSameStage() } or
   TVariableNode(Variable var, int indirectionIndex) {
-    indirectionIndex = [1 .. Ssa::getMaxIndirectionsForType(var.getUnspecifiedType())]
+    indirectionIndex =
+      [getMinIndirectionsForType(var.getUnspecifiedType()) .. Ssa::getMaxIndirectionsForType(var.getUnspecifiedType())]
   } or
   TPostFieldUpdateNode(FieldAddress operand, int indirectionIndex) {
     indirectionIndex =
@@ -346,15 +347,17 @@ class Node extends TIRDataFlowNode {
    * Gets the variable corresponding to this node, if any. This can be used for
    * modeling flow in and out of global variables.
    */
-  Variable asVariable() { this = TVariableNode(result, 1) }
+  Variable asVariable() {
+    this = TVariableNode(result, getMinIndirectionsForType(result.getUnspecifiedType()))
+  }
 
   /**
    * Gets the `indirectionIndex`'th indirection of this node's underlying variable, if any.
    *
    * This can be used for modeling flow in and out of global variables.
    */
   Variable asIndirectVariable(int indirectionIndex) {
-    indirectionIndex > 1 and
+    indirectionIndex > getMinIndirectionsForType(result.getUnspecifiedType()) and
     this = TVariableNode(result, indirectionIndex)
   }
 
@@ -432,6 +435,10 @@ private class Node0 extends Node, TNode0 {
 
   override Declaration getFunction() { result = node.getFunction() }
 
+  override Location getLocationImpl() { result = node.getLocation() }
+
+  override string toStringImpl() { result = node.toString() }
+
   override DataFlowType getType() { result = node.getType() }
 
   override predicate isGLValue() { node.isGLValue() }
@@ -448,18 +455,6 @@ class InstructionNode extends Node0 {
 
   /** Gets the instruction corresponding to this node. */
   Instruction getInstruction() { result = instr }
-
-  override Location getLocationImpl() {
-    if exists(instr.getAst().getLocation())
-    then result = instr.getAst().getLocation()
-    else result instanceof UnknownDefaultLocation
-  }
-
-  override string toStringImpl() {
-    if instr.(InitializeParameterInstruction).getIRVariable() instanceof IRThisVariable
-    then result = "this"
-    else result = instr.getAst().toString()
-  }
 }
 
 /**
@@ -473,18 +468,6 @@ class OperandNode extends Node, Node0 {
 
   /** Gets the operand corresponding to this node. */
   Operand getOperand() { result = op }
-
-  override Location getLocationImpl() {
-    if exists(op.getDef().getAst().getLocation())
-    then result = op.getDef().getAst().getLocation()
-    else result instanceof UnknownDefaultLocation
-  }
-
-  override string toStringImpl() {
-    if op.getDef().(InitializeParameterInstruction).getIRVariable() instanceof IRThisVariable
-    then result = "this"
-    else result = op.getDef().getAst().toString()
-  }
 }
 
 /**
@@ -1293,31 +1276,90 @@ abstract private class IndirectExprNodeBase extends Node {
   }
 }
 
-private class IndirectOperandIndirectExprNode extends IndirectExprNodeBase instanceof IndirectOperand
-{
-  IndirectOperandIndirectExprNode() {
+/** A signature for converting an indirect node to an expression. */
+private signature module IndirectNodeToIndirectExprSig {
+  /** The indirect node class to be converted to an expression */
+  class IndirectNode;
+
+  /**
+   * Holds if the indirect expression at indirection index `indirectionIndex`
+   * of `node` is `e`. The integer `n` specifies how many conversions has been
+   * applied to `node`.
+   */
+  predicate indirectNodeHasIndirectExpr(IndirectNode node, Expr e, int n, int indirectionIndex);
+}
+
+/**
+ * A module that implements the logic for deciding whether an indirect node
+ * should be an `IndirectExprNode`.
+ */
+private module IndirectNodeToIndirectExpr<IndirectNodeToIndirectExprSig Sig> {
+  import Sig
+
+  /**
+   * This predicate shifts the indirection index by one when `conv` is a
+   * `ReferenceDereferenceExpr`.
+   *
+   * This is necessary because `ReferenceDereferenceExpr` is a conversion
+   * in the AST, but appears as a `LoadInstruction` in the IR.
+   */
+  bindingset[e, indirectionIndex]
+  private predicate adjustForReference(
+    Expr e, int indirectionIndex, Expr conv, int adjustedIndirectionIndex
+  ) {
+    conv.(ReferenceDereferenceExpr).getExpr() = e and
+    adjustedIndirectionIndex = indirectionIndex - 1
+    or
+    not conv instanceof ReferenceDereferenceExpr and
+    conv = e and
+    adjustedIndirectionIndex = indirectionIndex
+  }
+
+  /** Holds if `node` should be an `IndirectExprNode`. */
+  predicate charpred(IndirectNode node) {
     exists(Expr e, int n, int indirectionIndex |
-      indirectExprNodeShouldBeIndirectOperand(this, e, n, indirectionIndex) and
-      not indirectExprNodeShouldBeIndirectOperand(_, e, n + 1, indirectionIndex)
+      indirectNodeHasIndirectExpr(node, e, n, indirectionIndex) and
+      not exists(Expr conv, int adjustedIndirectionIndex |
+        adjustForReference(e, indirectionIndex, conv, adjustedIndirectionIndex) and
+        indirectNodeHasIndirectExpr(_, conv, n + 1, adjustedIndirectionIndex)
+      )
     )
   }
+}
+
+private module IndirectOperandIndirectExprNodeImpl implements IndirectNodeToIndirectExprSig {
+  class IndirectNode = IndirectOperand;
+
+  predicate indirectNodeHasIndirectExpr = indirectExprNodeShouldBeIndirectOperand/4;
+}
+
+module IndirectOperandToIndirectExpr =
+  IndirectNodeToIndirectExpr<IndirectOperandIndirectExprNodeImpl>;
+
+private class IndirectOperandIndirectExprNode extends IndirectExprNodeBase instanceof IndirectOperand
+{
+  IndirectOperandIndirectExprNode() { IndirectOperandToIndirectExpr::charpred(this) }
 
   final override Expr getConvertedExpr(int n, int index) {
-    indirectExprNodeShouldBeIndirectOperand(this, result, n, index)
+    IndirectOperandToIndirectExpr::indirectNodeHasIndirectExpr(this, result, n, index)
   }
 }
 
+private module IndirectInstructionIndirectExprNodeImpl implements IndirectNodeToIndirectExprSig {
+  class IndirectNode = IndirectInstruction;
+
+  predicate indirectNodeHasIndirectExpr = indirectExprNodeShouldBeIndirectInstruction/4;
+}
+
+module IndirectInstructionToIndirectExpr =
+  IndirectNodeToIndirectExpr<IndirectInstructionIndirectExprNodeImpl>;
+
 private class IndirectInstructionIndirectExprNode extends IndirectExprNodeBase instanceof IndirectInstruction
 {
-  IndirectInstructionIndirectExprNode() {
-    exists(Expr e, int n, int indirectionIndex |
-      indirectExprNodeShouldBeIndirectInstruction(this, e, n, indirectionIndex) and
-      not indirectExprNodeShouldBeIndirectInstruction(_, e, n + 1, indirectionIndex)
-    )
-  }
+  IndirectInstructionIndirectExprNode() { IndirectInstructionToIndirectExpr::charpred(this) }
 
   final override Expr getConvertedExpr(int n, int index) {
-    indirectExprNodeShouldBeIndirectInstruction(this, result, n, index)
+    IndirectInstructionToIndirectExpr::indirectNodeHasIndirectExpr(this, result, n, index)
   }
 }