Merge branch 'main' into rdmarsh2/cpp/hex-format-range-analysis

Accept test changes from query split

cpp/config/suites/security/cwe-120

@@ -5,9 +5,11 @@
   @name Badly bounded write (CWE-120)
 + semmlecode-cpp-queries/Security/CWE/CWE-120/OverrunWrite.ql: /CWE/CWE-120
   @name Potentially overrunning write (CWE-120)
++ semmlecode-cpp-queries/Security/CWE/CWE-120/VeryLikelyOverrunWrite.ql: /CWE/CWE-120
+  @name Likely overrunning write
 + semmlecode-cpp-queries/Security/CWE/CWE-120/OverrunWriteFloat.ql: /CWE/CWE-120
   @name Potentially overrunning write with float to string conversion (CWE-120)
 + semmlecode-cpp-queries/Best Practices/Likely Errors/OffsetUseBeforeRangeCheck.ql: /CWE/CWE-120
   @name Array offset used before range check (CWE-120)
 + semmlecode-cpp-queries/Likely Bugs/Memory Management/UnsafeUseOfStrcat.ql: /CWE/CWE-120
-    @name Potentially unsafe use of strcat (CWE-120)
+  @name Potentially unsafe use of strcat (CWE-120)

cpp/ql/lib/change-notes/2022-01-11-remove-upgrades-packs.md

@@ -0,0 +1,4 @@
+---
+category: deprecated
+---
+* The `codeql/cpp-upgrades` CodeQL pack has been removed. All upgrades scripts have been merged into the `codeql/cpp-all` CodeQL pack.

cpp/ql/lib/qlpack.yml

@@ -4,5 +4,4 @@ groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp
 library: true
-dependencies:
-  codeql/cpp-upgrades: ^0.0.3
+upgrades: upgrades

cpp/ql/lib/semmle/code/cpp/commons/Printf.qll

@@ -10,10 +10,22 @@ private import semmle.code.cpp.rangeanalysis.SimpleRangeAnalysis
 private import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
 
 private newtype TBufferWriteEstimationReason =
-  TNoSpecifiedEstimateReason() or
+  TUnspecifiedEstimateReason() or
   TTypeBoundsAnalysis() or
+  TWidenedValueFlowAnalysis() or
   TValueFlowAnalysis()
 
+private predicate gradeToReason(int grade, TBufferWriteEstimationReason reason) {
+  // when combining reasons, lower grade takes precedence
+  grade = 0 and reason = TUnspecifiedEstimateReason()
+  or
+  grade = 1 and reason = TTypeBoundsAnalysis()
+  or
+  grade = 2 and reason = TWidenedValueFlowAnalysis()
+  or
+  grade = 3 and reason = TValueFlowAnalysis()
+}
+
 /**
  * A reason for a specific buffer write size estimate.
  */
@@ -32,7 +44,13 @@ abstract class BufferWriteEstimationReason extends TBufferWriteEstimationReason
    * Combine estimate reasons. Used to give a reason for the size of a format string
    * conversion given reasons coming from its individual specifiers.
    */
-  abstract BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other);
+  BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
+    exists(int grade, int otherGrade |
+      gradeToReason(grade, this) and gradeToReason(otherGrade, other)
+    |
+      if otherGrade < grade then result = other else result = this
+    )
+  }
 }
 
 /**
@@ -40,16 +58,10 @@ abstract class BufferWriteEstimationReason extends TBufferWriteEstimationReason
  * classes derived from BufferWrite and overriding `getMaxData/0` still work with the
  * queries as intended.
  */
-class NoSpecifiedEstimateReason extends BufferWriteEstimationReason, TNoSpecifiedEstimateReason {
-  override string toString() { result = "NoSpecifiedEstimateReason" }
+class UnspecifiedEstimateReason extends BufferWriteEstimationReason, TUnspecifiedEstimateReason {
+  override string toString() { result = "UnspecifiedEstimateReason" }
 
   override string getDescription() { result = "no reason specified" }
-
-  override BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
-    // this reason should not be used in format specifiers, so it should not be combined
-    // with other reasons
-    none()
-  }
 }
 
 /**
@@ -60,9 +72,24 @@ class TypeBoundsAnalysis extends BufferWriteEstimationReason, TTypeBoundsAnalysi
   override string toString() { result = "TypeBoundsAnalysis" }
 
   override string getDescription() { result = "based on type bounds" }
+}
 
-  override BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
-    other != TNoSpecifiedEstimateReason() and result = TTypeBoundsAnalysis()
+/**
+ * The estimation comes from non trivial bounds found via actual flow analysis,
+ * but a widening aproximation might have been used for variables in loops.
+ * For example
+ * ```
+ * for (int i = 0; i < 10; ++i) {
+ *    int j = i + i;
+ *    //...  <- estimation done here based on j
+ * }
+ * ```
+ */
+class WidenedValueFlowAnalysis extends BufferWriteEstimationReason, TWidenedValueFlowAnalysis {
+  override string toString() { result = "WidenedValueFlowAnalysis" }
+
+  override string getDescription() {
+    result = "based on flow analysis of value bounds with a widening approximation"
   }
 }
 
@@ -80,10 +107,6 @@ class ValueFlowAnalysis extends BufferWriteEstimationReason, TValueFlowAnalysis
   override string toString() { result = "ValueFlowAnalysis" }
 
   override string getDescription() { result = "based on flow analysis of value bounds" }
-
-  override BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
-    other != TNoSpecifiedEstimateReason() and result = other
-  }
 }
 
 class PrintfFormatAttribute extends FormatAttribute {
@@ -359,6 +382,23 @@ private int lengthInBase10(float f) {
   result = f.log10().floor() + 1
 }
 
+bindingset[expr]
+private BufferWriteEstimationReason getEstimationReasonForIntegralExpression(Expr expr) {
+  // we consider the range analysis non trivial if it
+  // * constrained non-trivially both sides of a signed value, or
+  // * constrained non-trivially the positive side of an unsigned value
+  // expr should already be given as getFullyConverted
+  if
+    upperBound(expr) < exprMaxVal(expr) and
+    (exprMinVal(expr) >= 0 or lowerBound(expr) > exprMinVal(expr))
+  then
+    // next we check whether the estimate may have been widened
+    if upperBoundMayBeWidened(expr)
+    then result = TWidenedValueFlowAnalysis()
+    else result = TValueFlowAnalysis()
+  else result = TTypeBoundsAnalysis()
+}
+
 /**
  * Gets the number of hex digits required to represent the integer represented by `f`.
  *
@@ -1169,12 +1209,10 @@ class FormatLiteral extends Literal {
             1 + lengthInBase10(2.pow(this.getIntegralDisplayType(n).getSize() * 8 - 1)) and
           // The second case uses range analysis to deduce a length that's shorter than the length
           // of the number -2^31.
-          exists(Expr arg, float lower, float upper, float typeLower, float typeUpper |
+          exists(Expr arg, float lower, float upper |
             arg = this.getUse().getConversionArgument(n) and
             lower = lowerBound(arg.getFullyConverted()) and
-            upper = upperBound(arg.getFullyConverted()) and
-            typeLower = exprMinVal(arg.getFullyConverted()) and
-            typeUpper = exprMaxVal(arg.getFullyConverted())
+            upper = upperBound(arg.getFullyConverted())
           |
             valueBasedBound =
               max(int cand |
@@ -1191,11 +1229,9 @@ class FormatLiteral extends Literal {
                   else cand = lengthInBase10(upper)
                 )
               ) and
-            (
-              if lower > typeLower or upper < typeUpper
-              then reason = TValueFlowAnalysis()
-              else reason = TTypeBoundsAnalysis()
-            )
+            // we don't want to call this on `arg.getFullyConverted()` as we want
+            // to detect non-trivial range analysis without taking into account up-casting
+            reason = getEstimationReasonForIntegralExpression(arg)
           ) and
           len = valueBasedBound.minimum(typeBasedBound)
         )
@@ -1207,12 +1243,10 @@ class FormatLiteral extends Literal {
           typeBasedBound = lengthInBase10(2.pow(this.getIntegralDisplayType(n).getSize() * 8) - 1) and
           // The second case uses range analysis to deduce a length that's shorter than
           // the length of the number 2^31 - 1.
-          exists(Expr arg, float lower, float upper, float typeLower, float typeUpper |
+          exists(Expr arg, float lower, float upper |
             arg = this.getUse().getConversionArgument(n) and
             lower = lowerBound(arg.getFullyConverted()) and
-            upper = upperBound(arg.getFullyConverted()) and
-            typeLower = exprMinVal(arg.getFullyConverted()) and
-            typeUpper = exprMaxVal(arg.getFullyConverted())
+            upper = upperBound(arg.getFullyConverted())
           |
             valueBasedBound =
               lengthInBase10(max(float cand |
@@ -1222,11 +1256,9 @@ class FormatLiteral extends Literal {
                   or
                   cand = upper
                 )) and
-            (
-              if lower > typeLower or upper < typeUpper
-              then reason = TValueFlowAnalysis()
-              else reason = TTypeBoundsAnalysis()
-            )
+            // we don't want to call this on `arg.getFullyConverted()` as we want
+            // to detect non-trivial range analysis without taking into account up-casting
+            reason = getEstimationReasonForIntegralExpression(arg)
           ) and
           len = valueBasedBound.minimum(typeBasedBound)
         )

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll

@@ -3,6 +3,17 @@ private import DataFlowImplSpecific::Public
 import Cached
 
 module DataFlowImplCommonPublic {
+  /** A state value to track during data flow. */
+  class FlowState = string;
+
+  /**
+   * The default state, which is used when the state is unspecified for a source
+   * or a sink.
+   */
+  class FlowStateEmpty extends FlowState {
+    FlowStateEmpty() { this = "" }
+  }
+
   private newtype TFlowFeature =
     TFeatureHasSourceCallContext() or
     TFeatureHasSinkCallContext() or

cpp/ql/lib/semmle/code/cpp/dataflow/internal/FlowVar.qll

@@ -435,7 +435,7 @@ module FlowVar_internal {
       parameterIsNonConstReference(p) and
       p = v and
       // This definition reaches the exit node of the function CFG
-      getAReachedBlockVarSBB(this).getANode() = p.getFunction()
+      getAReachedBlockVarSBB(this).getEnd() = p.getFunction()
     }
 
     override predicate definedByInitialValue(StackVariable lsv) {

cpp/ql/lib/semmle/code/cpp/dataflow/internal/TaintTrackingUtil.qll

@@ -47,6 +47,12 @@ predicate defaultImplicitTaintRead(DataFlow::Node node, DataFlow::Content c) { n
  */
 predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
 
+/**
+ * Holds if `guard` should be a sanitizer guard in all global taint flow configurations
+ * but not in local taint.
+ */
+predicate defaultTaintSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+
 /**
  * Holds if taint can flow in one local step from `nodeFrom` to `nodeTo` excluding
  * local data flow steps. That is, `nodeFrom` and `nodeTo` are likely to represent

cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSource(DataFlow::Node source);
+  override predicate isSource(DataFlow::Node source) { none() }
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSink(DataFlow::Node sink);
+  override predicate isSink(DataFlow::Node sink) { none() }
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard)
+    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSource(DataFlow::Node source);
+  override predicate isSource(DataFlow::Node source) { none() }
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSink(DataFlow::Node sink);
+  override predicate isSink(DataFlow::Node sink) { none() }
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard)
+    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowDispatch.qll

@@ -63,7 +63,7 @@ private module VirtualDispatch {
         this.flowsFrom(other, allowOtherFromArg)
       |
         // Call argument
-        exists(DataFlowCall call, int i |
+        exists(DataFlowCall call, Position i |
           other
               .(DataFlow::ParameterNode)
               .isParameterOf(pragma[only_bind_into](call).getStaticCallTarget(), i) and
@@ -268,16 +268,6 @@ Function viableImplInCallContext(CallInstruction call, CallInstruction ctx) {
   )
 }
 
-/** A parameter position represented by an integer. */
-class ParameterPosition extends int {
-  ParameterPosition() { any(ParameterNode p).isParameterOf(_, this) }
-}
-
-/** An argument position represented by an integer. */
-class ArgumentPosition extends int {
-  ArgumentPosition() { any(ArgumentNode a).argumentOf(_, this) }
-}
-
 /** Holds if arguments at position `apos` match parameters at position `ppos`. */
 pragma[inline]
 predicate parameterMatch(ParameterPosition ppos, ArgumentPosition apos) { ppos = apos }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll

@@ -3,6 +3,17 @@ private import DataFlowImplSpecific::Public
 import Cached
 
 module DataFlowImplCommonPublic {
+  /** A state value to track during data flow. */
+  class FlowState = string;
+
+  /**
+   * The default state, which is used when the state is unspecified for a source
+   * or a sink.
+   */
+  class FlowStateEmpty extends FlowState {
+    FlowStateEmpty() { this = "" }
+  }
+
   private newtype TFlowFeature =
     TFeatureHasSourceCallContext() or
     TFeatureHasSinkCallContext() or

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -27,7 +27,7 @@ abstract class ArgumentNode extends OperandNode {
    * Holds if this argument occurs at the given position in the given call.
    * The instance argument is considered to have index `-1`.
    */
-  abstract predicate argumentOf(DataFlowCall call, int pos);
+  abstract predicate argumentOf(DataFlowCall call, ArgumentPosition pos);
 
   /** Gets the call in which this node is an argument. */
   DataFlowCall getCall() { this.argumentOf(result, _) }
@@ -42,7 +42,9 @@ private class PrimaryArgumentNode extends ArgumentNode {
 
   PrimaryArgumentNode() { exists(CallInstruction call | op = call.getAnArgumentOperand()) }
 
-  override predicate argumentOf(DataFlowCall call, int pos) { op = call.getArgumentOperand(pos) }
+  override predicate argumentOf(DataFlowCall call, ArgumentPosition pos) {
+    op = call.getArgumentOperand(pos.(DirectPosition).getIndex())
+  }
 
   override string toString() {
     exists(Expr unconverted |
@@ -71,9 +73,9 @@ private class SideEffectArgumentNode extends ArgumentNode {
 
   SideEffectArgumentNode() { op = read.getSideEffectOperand() }
 
-  override predicate argumentOf(DataFlowCall call, int pos) {
+  override predicate argumentOf(DataFlowCall call, ArgumentPosition pos) {
     read.getPrimaryInstruction() = call and
-    pos = getArgumentPosOfSideEffect(read.getIndex())
+    pos.(IndirectionPosition).getIndex() = read.getIndex()
   }
 
   override string toString() {
@@ -90,6 +92,54 @@ private class SideEffectArgumentNode extends ArgumentNode {
   }
 }
 
+/** A parameter position represented by an integer. */
+class ParameterPosition = Position;
+
+/** An argument position represented by an integer. */
+class ArgumentPosition = Position;
+
+class Position extends TPosition {
+  abstract string toString();
+}
+
+class DirectPosition extends TDirectPosition {
+  int index;
+
+  DirectPosition() { this = TDirectPosition(index) }
+
+  string toString() {
+    index = -1 and
+    result = "this"
+    or
+    index != -1 and
+    result = index.toString()
+  }
+
+  int getIndex() { result = index }
+}
+
+class IndirectionPosition extends TIndirectionPosition {
+  int index;
+
+  IndirectionPosition() { this = TIndirectionPosition(index) }
+
+  string toString() {
+    index = -1 and
+    result = "this"
+    or
+    index != -1 and
+    result = index.toString()
+  }
+
+  int getIndex() { result = index }
+}
+
+newtype TPosition =
+  TDirectPosition(int index) { exists(any(CallInstruction c).getArgument(index)) } or
+  TIndirectionPosition(int index) {
+    exists(ReadSideEffectInstruction instr | instr.getIndex() = index)
+  }
+
 private newtype TReturnKind =
   TNormalReturnKind() or
   TIndirectReturnKind(ParameterIndex index)

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -490,19 +490,6 @@ class ExprNode extends InstructionNode {
   override string toString() { result = this.asConvertedExpr().toString() }
 }
 
-/**
- * INTERNAL: do not use. Translates a parameter/argument index into a negative
- * number that denotes the index of its side effect (pointer indirection).
- */
-bindingset[index]
-int getArgumentPosOfSideEffect(int index) {
-  // -1 -> -2
-  //  0 -> -3
-  //  1 -> -4
-  // ...
-  result = -3 - index
-}
-
 /**
  * The value of a parameter at function entry, viewed as a node in a data
  * flow graph. This includes both explicit parameters such as `x` in `f(x)`
@@ -525,7 +512,7 @@ class ParameterNode extends InstructionNode {
    * implicit `this` parameter is considered to have position `-1`, and
    * pointer-indirection parameters are at further negative positions.
    */
-  predicate isParameterOf(Function f, int pos) { none() } // overridden by subclasses
+  predicate isParameterOf(Function f, ParameterPosition pos) { none() } // overridden by subclasses
 }
 
 /** An explicit positional parameter, not including `this` or `...`. */
@@ -534,8 +521,8 @@ private class ExplicitParameterNode extends ParameterNode {
 
   ExplicitParameterNode() { exists(instr.getParameter()) }
 
-  override predicate isParameterOf(Function f, int pos) {
-    f.getParameter(pos) = instr.getParameter()
+  override predicate isParameterOf(Function f, ParameterPosition pos) {
+    f.getParameter(pos.(DirectPosition).getIndex()) = instr.getParameter()
   }
 
   /** Gets the `Parameter` associated with this node. */
@@ -550,8 +537,8 @@ class ThisParameterNode extends ParameterNode {
 
   ThisParameterNode() { instr.getIRVariable() instanceof IRThisVariable }
 
-  override predicate isParameterOf(Function f, int pos) {
-    pos = -1 and instr.getEnclosingFunction() = f
+  override predicate isParameterOf(Function f, ParameterPosition pos) {
+    pos.(DirectPosition).getIndex() = -1 and instr.getEnclosingFunction() = f
   }
 
   override string toString() { result = "this" }
@@ -561,12 +548,12 @@ class ThisParameterNode extends ParameterNode {
 class ParameterIndirectionNode extends ParameterNode {
   override InitializeIndirectionInstruction instr;
 
-  override predicate isParameterOf(Function f, int pos) {
+  override predicate isParameterOf(Function f, ParameterPosition pos) {
     exists(int index |
       instr.getEnclosingFunction() = f and
       instr.hasIndex(index)
     |
-      pos = getArgumentPosOfSideEffect(index)
+      pos.(IndirectionPosition).getIndex() = index
     )
   }
 

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImplCommon.qll

@@ -659,4 +659,15 @@ module Consistency {
     not phiHasInputFromBlock(_, def, _) and
     not uncertainWriteDefinitionInput(_, def)
   }
+
+  query predicate notDominatedByDef(RelevantDefinition def, SourceVariable v, BasicBlock bb, int i) {
+    exists(BasicBlock bbDef, int iDef | def.definesAt(v, bbDef, iDef) |
+      ssaDefReachesReadWithinBlock(v, def, bb, i) and
+      (bb != bbDef or i < iDef)
+      or
+      ssaDefReachesRead(v, def, bb, i) and
+      not ssaDefReachesReadWithinBlock(v, def, bb, i) and
+      not def.definesAt(v, getImmediateBasicBlockDominator*(bb), _)
+    )
+  }
 }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/TaintTrackingUtil.qll

@@ -160,6 +160,12 @@ predicate defaultImplicitTaintRead(DataFlow::Node node, DataFlow::Content c) { n
  */
 predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
 
+/**
+ * Holds if `guard` should be a sanitizer guard in all global taint flow configurations
+ * but not in local taint.
+ */
+predicate defaultTaintSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+
 /**
  * Holds if taint can flow from `instrIn` to `instrOut` through a call to a
  * modeled function.

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSource(DataFlow::Node source);
+  override predicate isSource(DataFlow::Node source) { none() }
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSink(DataFlow::Node sink);
+  override predicate isSink(DataFlow::Node sink) { none() }
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard)
+    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSource(DataFlow::Node source);
+  override predicate isSource(DataFlow::Node source) { none() }
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSink(DataFlow::Node sink);
+  override predicate isSink(DataFlow::Node sink) { none() }
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard)
+    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSource(DataFlow::Node source);
+  override predicate isSource(DataFlow::Node source) { none() }
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  abstract override predicate isSink(DataFlow::Node sink);
+  override predicate isSink(DataFlow::Node sink) { none() }
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard)
+    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/security/BufferWrite.qll

@@ -76,7 +76,7 @@ abstract class BufferWrite extends Expr {
    * can be found), specifying the reason for the estimation.
    */
   int getMaxData(BufferWriteEstimationReason reason) {
-    reason instanceof NoSpecifiedEstimateReason and result = getMaxData()
+    reason instanceof UnspecifiedEstimateReason and result = getMaxData()
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/security/Overflow.qll

@@ -9,6 +9,7 @@ import semmle.code.cpp.controlflow.Dominance
 private import semmle.code.cpp.valuenumbering.GlobalValueNumbering
 import semmle.code.cpp.rangeanalysis.SimpleRangeAnalysis
 import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
+import semmle.code.cpp.controlflow.Guards
 
 /**
  * Holds if the value of `use` is guarded using `abs`.
@@ -16,53 +17,16 @@ import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
 predicate guardedAbs(Operation e, Expr use) {
   exists(FunctionCall fc | fc.getTarget().getName() = ["abs", "labs", "llabs", "imaxabs"] |
     fc.getArgument(0).getAChild*() = use and
-    guardedLesser(e, fc)
+    exists(GuardCondition c | c.ensuresLt(fc, _, _, e.getBasicBlock(), true))
   )
 }
 
-/**
- * Gets the position of `stmt` in basic block `block` (this is a thin layer
- * over `BasicBlock.getNode`, intended to improve performance).
- */
-pragma[noinline]
-private int getStmtIndexInBlock(BasicBlock block, Stmt stmt) { block.getNode(result) = stmt }
-
-pragma[inline]
-private predicate stmtDominates(Stmt dominator, Stmt dominated) {
-  // In same block
-  exists(BasicBlock block, int dominatorIndex, int dominatedIndex |
-    dominatorIndex = getStmtIndexInBlock(block, dominator) and
-    dominatedIndex = getStmtIndexInBlock(block, dominated) and
-    dominatedIndex >= dominatorIndex
-  )
-  or
-  // In (possibly) different blocks
-  bbStrictlyDominates(dominator.getBasicBlock(), dominated.getBasicBlock())
-}
-
 /**
  * Holds if the value of `use` is guarded to be less than something, and `e`
  * is in code controlled by that guard (where the guard condition held).
  */
-pragma[nomagic]
 predicate guardedLesser(Operation e, Expr use) {
-  exists(IfStmt c, RelationalOperation guard |
-    use = guard.getLesserOperand().getAChild*() and
-    guard = c.getControllingExpr().getAChild*() and
-    stmtDominates(c.getThen(), e.getEnclosingStmt())
-  )
-  or
-  exists(Loop c, RelationalOperation guard |
-    use = guard.getLesserOperand().getAChild*() and
-    guard = c.getControllingExpr().getAChild*() and
-    stmtDominates(c.getStmt(), e.getEnclosingStmt())
-  )
-  or
-  exists(ConditionalExpr c, RelationalOperation guard |
-    use = guard.getLesserOperand().getAChild*() and
-    guard = c.getCondition().getAChild*() and
-    c.getThen().getAChild*() = e
-  )
+  exists(GuardCondition c | c.ensuresLt(use, _, _, e.getBasicBlock(), true))
   or
   guardedAbs(e, use)
 }
@@ -71,25 +35,8 @@ predicate guardedLesser(Operation e, Expr use) {
  * Holds if the value of `use` is guarded to be greater than something, and `e`
  * is in code controlled by that guard (where the guard condition held).
  */
-pragma[nomagic]
 predicate guardedGreater(Operation e, Expr use) {
-  exists(IfStmt c, RelationalOperation guard |
-    use = guard.getGreaterOperand().getAChild*() and
-    guard = c.getControllingExpr().getAChild*() and
-    stmtDominates(c.getThen(), e.getEnclosingStmt())
-  )
-  or
-  exists(Loop c, RelationalOperation guard |
-    use = guard.getGreaterOperand().getAChild*() and
-    guard = c.getControllingExpr().getAChild*() and
-    stmtDominates(c.getStmt(), e.getEnclosingStmt())
-  )
-  or
-  exists(ConditionalExpr c, RelationalOperation guard |
-    use = guard.getGreaterOperand().getAChild*() and
-    guard = c.getCondition().getAChild*() and
-    c.getThen().getAChild*() = e
-  )
+  exists(GuardCondition c | c.ensuresLt(use, _, _, e.getBasicBlock(), false))
   or
   guardedAbs(e, use)
 }