majacQ · pull · Apr 14, 2021 · Apr 14, 2021 · Apr 14, 2021 · Apr 14, 2021
diff --git a/.github/workflows/close-stale.yml b/.github/workflows/close-stale.yml
@@ -0,0 +1,30 @@
+name: Mark stale issues
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "30 1 * * *"
+
+jobs:
+  stale:
+    if: github.repository == 'github/codeql'
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/stale@v3
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        stale-issue-message: 'This issue is stale because it has been open 14 days with no activity. Comment or remove the `Stale` label in order to avoid having this issue closed in 7 days.'
+        close-issue-message: 'This issue was closed because it has been inactive for 7 days.'
+        days-before-stale: 14
+        days-before-close: 7
+        only-labels: awaiting-response
+
+        # do not mark PRs as stale
+        days-before-pr-stale: -1
+        days-before-pr-close: -1
+
+        # Uncomment for dry-run
+        # debug-only: true
+        # operations-per-run: 1000
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
@@ -19,13 +19,18 @@ jobs:
 
     runs-on: ubuntu-latest
 
+    permissions:
+      contents: read
+      security-events: write
+      pull-requests: read
+
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v1
+      uses: github/codeql-action/init@main
       # Override language selection by uncommenting this and choosing your languages
       with:
         languages: csharp
@@ -34,7 +39,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v1
+      uses: github/codeql-action/autobuild@main
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 https://git.io/JvXDl
@@ -48,4 +53,4 @@ jobs:
     #   make release
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v1
+      uses: github/codeql-action/analyze@main
diff --git a/config/identical-files.json b/config/identical-files.json
@@ -5,6 +5,7 @@
     "java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl3.qll",
     "java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl4.qll",
     "java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl5.qll",
+    "java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl6.qll",
     "cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll",
     "cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll",
     "cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll",
@@ -56,6 +57,10 @@
     "csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplConsistency.qll",
     "python/ql/src/semmle/python/dataflow/new/internal/DataFlowImplConsistency.qll"
   ],
+  "DataFlow Java/C# Flow Summaries": [
+    "java/ql/src/semmle/code/java/dataflow/internal/FlowSummaryImpl.qll",
+    "csharp/ql/src/semmle/code/csharp/dataflow/internal/FlowSummaryImpl.qll"
+  ],
   "SsaReadPosition Java/C#": [
     "java/ql/src/semmle/code/java/dataflow/internal/rangeanalysis/SsaReadPositionCommon.qll",
     "csharp/ql/src/semmle/code/csharp/dataflow/internal/rangeanalysis/SsaReadPositionCommon.qll"

diff --git a/cpp/change-notes/2021-04-13-arithmetic-queries.md b/cpp/change-notes/2021-04-13-arithmetic-queries.md
@@ -0,0 +1,2 @@
+lgtm
+* The queries cpp/tainted-arithmetic, cpp/uncontrolled-arithmetic, and cpp/arithmetic-with-extreme-values have been improved to produce fewer false positives.
diff --git a/cpp/change-notes/2021-04-21-return-stack-allocated-object.md b/cpp/change-notes/2021-04-21-return-stack-allocated-object.md
@@ -0,0 +1,2 @@
+codescanning
+* The 'Pointer to stack object used as return value' (cpp/return-stack-allocated-object) query has been deprecated, and any uses should be replaced with `Returning stack-allocated memory` (cpp/return-stack-allocated-memory).
diff --git a/cpp/change-notes/2021-26-04-more-sound-expr-might-overflow.md b/cpp/change-notes/2021-26-04-more-sound-expr-might-overflow.md
@@ -0,0 +1,2 @@
+lgtm,codescanning
+* The `exprMightOverflowPositively` and `exprMightOverflowNegatively` predicates from the `SimpleRangeAnalysis` library now recognize more expressions that might overflow.
diff --git a/cpp/ql/src/Best Practices/Magic Constants/MagicConstantsNumbers.qhelp b/cpp/ql/src/Best Practices/Magic Constants/MagicConstantsNumbers.qhelp
@@ -39,7 +39,7 @@ then replace all the relevant occurrences in the code.</p>
 </li>
 <li>
   Mats Henricson and Erik Nyquist, <i>Industrial Strength C++</i>, published by Prentice Hall PTR (1997). 
-  Chapter 5: Object Life Cycle, Rec 5.4 (<a href="http://mongers.org/industrial-c++/">PDF</a>).
+  Chapter 5: Object Life Cycle, Rec 5.4 (<a href="https://web.archive.org/web/20190919025638/https://mongers.org/industrial-c++/">PDF</a>).
 </li>
 <li>
   <a href="https://www.securecoding.cert.org/confluence/display/c/DCL06-C.+Use+meaningful+symbolic+constants+to+represent+literal+values">DCL06-C. Use meaningful symbolic constants to represent literal values</a>

diff --git a/cpp/ql/src/Best Practices/Magic Constants/MagicConstantsString.qhelp b/cpp/ql/src/Best Practices/Magic Constants/MagicConstantsString.qhelp
@@ -38,7 +38,7 @@ constant.</p>
 </li>
 <li>
   Mats Henricson and Erik Nyquist, <i>Industrial Strength C++</i>, published by Prentice Hall PTR (1997). 
-  Chapter 5: Object Life Cycle, Rec 5.4 (<a href="http://mongers.org/industrial-c++/">PDF</a>).
+  Chapter 5: Object Life Cycle, Rec 5.4 (<a href="https://web.archive.org/web/20190919025638/https://mongers.org/industrial-c++/">PDF</a>).
 </li>
 <li>
   <a href="https://www.securecoding.cert.org/confluence/display/c/DCL06-C.+Use+meaningful+symbolic+constants+to+represent+literal+values">DCL06-C. Use meaningful symbolic constants to represent literal values</a>

diff --git a/cpp/ql/src/Best Practices/SloppyGlobal.qhelp b/cpp/ql/src/Best Practices/SloppyGlobal.qhelp
@@ -21,7 +21,7 @@ Review the purpose of the each global variable flagged by this rule and update e
 
 <li>
   Mats Henricson and Erik Nyquist, <i>Industrial Strength C++</i>, published by Prentice Hall PTR (1997). 
-  Chapter 1: Naming, Rec 1.1 (<a href="http://mongers.org/industrial-c++/">PDF</a>).
+  Chapter 1: Naming, Rec 1.1 (<a href="https://web.archive.org/web/20190919025638/https://mongers.org/industrial-c++/">PDF</a>).
 </li>
 <li>
   <a href="http://www.learncpp.com/cpp-tutorial/42-global-variables/">Global variables</a>.

diff --git a/cpp/ql/src/Best Practices/UseOfGoto.qhelp b/cpp/ql/src/Best Practices/UseOfGoto.qhelp
@@ -45,7 +45,7 @@ this rule.
 </li>
 <li>
   Mats Henricson and Erik Nyquist, <i>Industrial Strength C++</i>, Rule 4.6. Prentice Hall PTR, 1997.
-  (<a href="http://mongers.org/industrial-c++/">PDF</a>).
+  (<a href="https://web.archive.org/web/20190919025638/https://mongers.org/industrial-c++/">PDF</a>).
 </li>
 <li>
   cplusplus.com: <a href="http://www.cplusplus.com/doc/tutorial/control/">Control Structures</a>.

diff --git a/cpp/ql/src/Critical/ReturnStackAllocatedObject.ql b/cpp/ql/src/Critical/ReturnStackAllocatedObject.ql
@@ -7,6 +7,8 @@
  * @tags reliability
  *       security
  *       external/cwe/cwe-562
+ * @deprecated This query is not suitable for production use and has been deprecated. Use
+ *             cpp/return-stack-allocated-memory instead.
  */
 
 import semmle.code.cpp.pointsto.PointsTo

diff --git a/cpp/ql/src/Critical/ReturnValueIgnored.qhelp b/cpp/ql/src/Critical/ReturnValueIgnored.qhelp
@@ -32,7 +32,7 @@ Check the return value of functions that return status information.
 <references>
 
 <li>
-  M. Henricson and E. Nyquist, <i>Industrial Strength C++</i>, Chapter 12: Error handling. Prentice Hall PTR, 1997 (<a href="http://mongers.org/industrial-c++/">available online</a>).
+  M. Henricson and E. Nyquist, <i>Industrial Strength C++</i>, Chapter 12: Error handling. Prentice Hall PTR, 1997 (<a href="https://web.archive.org/web/20190919025638/https://mongers.org/industrial-c++/">available online</a>).
 </li>
 <li>
   The CERT C Secure Coding Standard: <a href="https://www.securecoding.cert.org/confluence/display/perl/EXP32-PL.+Do+not+ignore+function+return+values">EXP32-PL. Do not ignore function return values</a>.

diff --git a/cpp/ql/src/Likely Bugs/Likely Typos/MissingEnumCaseInSwitch.qhelp b/cpp/ql/src/Likely Bugs/Likely Typos/MissingEnumCaseInSwitch.qhelp
@@ -26,7 +26,7 @@ indication that there may be cases unhandled by the <code>switch</code> statemen
   MSDN Library: <a href="https://docs.microsoft.com/en-us/cpp/cpp/switch-statement-cpp">switch statement (C++)</a>
 </li>
 <li>
-  M. Henricson and E. Nyquist, <i>Industrial Strength C++</i>, Chapter 4: Control Flow, Rec 4.5. Prentice Hall PTR, 1997 (<a href="http://mongers.org/industrial-c++/">available online</a>).
+  M. Henricson and E. Nyquist, <i>Industrial Strength C++</i>, Chapter 4: Control Flow, Rec 4.5. Prentice Hall PTR, 1997 (<a href="https://web.archive.org/web/20190919025638/https://mongers.org/industrial-c++/">available online</a>).
 </li>
 
 

diff --git a/cpp/ql/src/Likely Bugs/Memory Management/ReturnStackAllocatedMemory.ql b/cpp/ql/src/Likely Bugs/Memory Management/ReturnStackAllocatedMemory.ql
@@ -13,6 +13,7 @@
 
 import cpp
 import semmle.code.cpp.dataflow.EscapesTree
+import semmle.code.cpp.models.interfaces.PointerWrapper
 import semmle.code.cpp.dataflow.DataFlow
 
 /**
@@ -39,6 +40,10 @@ predicate hasNontrivialConversion(Expr e) {
     e instanceof ParenthesisExpr
   )
   or
+  // A smart pointer can be stack-allocated while the data it points to is heap-allocated.
+  // So we exclude such "conversions" from this predicate.
+  e = any(PointerWrapper wrapper).getAnUnwrapperFunction().getACallToThisFunction()
+  or
   hasNontrivialConversion(e.getConversion())
 }
 

diff --git a/cpp/ql/src/Metrics/Files/FTransitiveIncludes.qhelp b/cpp/ql/src/Metrics/Files/FTransitiveIncludes.qhelp
@@ -29,7 +29,7 @@ build time: the more included files, the longer the compilation time.</p>
   <a href="http://www.drdobbs.com/cpp/decoupling-c-header-files/212701130">Decoupling C Header Files</a>
 </li>
 <li>
-  <a href="https://wiki.hsr.ch/Prog3/files/overload72-FINAL_DesigningHeaderFiles.pdf">C++ Best Practice -
+  <a href="https://accu.org/journals/overload/14/72/griffiths_1995/">C++ Best Practice -
 Designing Header Files</a>
 </li>
 

diff --git a/cpp/ql/src/Metrics/Files/FTransitiveSourceIncludes.qhelp b/cpp/ql/src/Metrics/Files/FTransitiveSourceIncludes.qhelp
@@ -35,7 +35,7 @@ they are contributing to unnecessarily long build times and creating artificial
   <a href="http://www.drdobbs.com/cpp/decoupling-c-header-files/212701130">Decoupling C Header Files</a>
 </li>
 <li>
-  <a href="https://wiki.hsr.ch/Prog3/files/overload72-FINAL_DesigningHeaderFiles.pdf">C++ Best Practice -
+  <a href="https://accu.org/journals/overload/14/72/griffiths_1995/">C++ Best Practice -
 Designing Header Files</a>
 </li>
 </references>

diff --git a/cpp/ql/src/Security/CWE/CWE-190/IntegerOverflowTainted.ql b/cpp/ql/src/Security/CWE/CWE-190/IntegerOverflowTainted.ql
@@ -28,6 +28,7 @@ predicate outOfBoundsExpr(Expr expr, string kind) {
 
 from Expr use, Expr origin, string kind
 where
+  not use.getUnspecifiedType() instanceof PointerType and
   outOfBoundsExpr(use, kind) and
   tainted(origin, use) and
   origin != use and

diff --git a/...erimental/Security/CWE/CWE-691/InsufficientControlFlowManagementAfterRefactoringTheCode.c b/...erimental/Security/CWE/CWE-691/InsufficientControlFlowManagementAfterRefactoringTheCode.c
@@ -0,0 +1,17 @@
+while(flagsLoop)
+{
+  ...
+  if(flagsIf) break;
+  ...
+}while(flagsLoop); // BAD: when exiting through `break`, it is possible to get into an eternal loop.
+...
+while(flagsLoop)
+{
+  ...
+  if(flagsIf) break;
+  ...
+} // GOOD: correct cycle
+...
+if(intA+intB) return 1; // BAD: possibly no comparison
+...
+if(intA+intB>intC) return 1; // GOOD: correct comparison
diff --git a/...ental/Security/CWE/CWE-691/InsufficientControlFlowManagementAfterRefactoringTheCode.qhelp b/...ental/Security/CWE/CWE-691/InsufficientControlFlowManagementAfterRefactoringTheCode.qhelp
@@ -0,0 +1,28 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+<p>In some situations, after code refactoring, parts of the old constructs may remain. They are correctly accepted by the compiler, but can critically affect program execution. For example, if you switch from `do {...} while ();` to `while () {...}` forgetting to remove the old construct completely, you get `while(){...}while();` which may be vulnerable. These code snippets look suspicious and require the developer's attention.</p>
+
+
+</overview>
+<recommendation>
+
+<p>We recommend that you use more explicit code transformations.</p>
+
+</recommendation>
+<example>
+<p>The following example demonstrates the erroneous and corrected sections of the code.</p>
+<sample src="InsufficientControlFlowManagementAfterRefactoringTheCode.c" />
+
+</example>
+<references>
+
+<li>
+  CWE Common Weakness Enumeration:
+  <a href="https://cwe.mitre.org/data/definitions/691.html"> CWE-691: Insufficient Control Flow Management</a>.
+</li>
+
+</references>
+</qhelp>
diff --git a/...rimental/Security/CWE/CWE-691/InsufficientControlFlowManagementAfterRefactoringTheCode.ql b/...rimental/Security/CWE/CWE-691/InsufficientControlFlowManagementAfterRefactoringTheCode.ql
@@ -0,0 +1,119 @@
+/**
+ * @name Errors After Refactoring
+ * @description --In some situations, after code refactoring, parts of the old constructs may remain.
+ *              --They are correctly accepted by the compiler, but can critically affect program execution.
+ *              --For example, if you switch from `do {...} while ();` to `while () {...}` with errors, you run the risk of running out of resources.
+ *              --These code snippets look suspicious and require the developer's attention.
+ * @kind problem
+ * @id cpp/errors-after-refactoring
+ * @problem.severity warning
+ * @precision medium
+ * @tags correctness
+ *       security
+ *       external/cwe/cwe-691
+ */
+
+import cpp
+import semmle.code.cpp.valuenumbering.HashCons
+import semmle.code.cpp.valuenumbering.GlobalValueNumbering
+
+/**
+ * Using `while` directly after the body of another` while`.
+ */
+class UsingWhileAfterWhile extends WhileStmt {
+  /**
+   * Using a loop call after another loop has finished running can result in an eternal loop.
+   * For example, perhaps as a result of refactoring, the `do ... while ()` loop was incorrectly corrected.
+   * Even in the case of deliberate use of such an expression, it is better to correct it.
+   */
+  UsingWhileAfterWhile() {
+    exists(WhileStmt wh1 |
+      wh1.getStmt().getAChild*().(BreakStmt).(ControlFlowNode).getASuccessor().getASuccessor() =
+        this and
+      hashCons(wh1.getCondition()) = hashCons(this.getCondition()) and
+      this.getStmt() instanceof EmptyStmt
+    )
+    or
+    exists(ForStmt fr1 |
+      fr1.getStmt().getAChild*().(BreakStmt).(ControlFlowNode).getASuccessor().getASuccessor() =
+        this and
+      hashCons(fr1.getCondition()) = hashCons(this.getCondition()) and
+      this.getStmt() instanceof EmptyStmt
+    )
+  }
+}
+
+/**
+ * Using arithmetic in a condition.
+ */
+class UsingArithmeticInComparison extends BinaryArithmeticOperation {
+  /**
+   * Using arithmetic operations in a comparison operation can be dangerous.
+   * For example, part of the comparison may have been lost as a result of refactoring.
+   * Even if you deliberately use such an expression, it is better to add an explicit comparison.
+   */
+  UsingArithmeticInComparison() {
+    this.getParent*() instanceof IfStmt and
+    not this.getAChild*().isConstant() and
+    not this.getParent*() instanceof Call and
+    not this.getParent*() instanceof AssignExpr and
+    not this.getParent*() instanceof ArrayExpr and
+    not this.getParent*() instanceof RemExpr and
+    not this.getParent*() instanceof AssignBitwiseOperation and
+    not this.getParent*() instanceof AssignArithmeticOperation and
+    not this.getParent*() instanceof EqualityOperation and
+    not this.getParent*() instanceof RelationalOperation
+  }
+
+  /** Holds when the expression is inside the loop body. */
+  predicate insideTheLoop() { exists(Loop lp | lp.getStmt().getAChild*() = this.getParent*()) }
+
+  /** Holds when the expression is used in binary operations. */
+  predicate workingWithValue() {
+    this.getParent*() instanceof BinaryBitwiseOperation or
+    this.getParent*() instanceof NotExpr
+  }
+
+  /** Holds when the expression contains a pointer. */
+  predicate workingWithPointer() {
+    this.getAChild*().getFullyConverted().getType() instanceof DerivedType
+  }
+
+  /** Holds when a null comparison expression exists. */
+  predicate compareWithZero() {
+    exists(Expr exp |
+      exp instanceof ComparisonOperation and
+      (
+        globalValueNumber(exp.getAChild*()) = globalValueNumber(this) or
+        hashCons(exp.getAChild*()) = hashCons(this)
+      ) and
+      (
+        exp.(ComparisonOperation).getLeftOperand().getValue() = "0" or
+        exp.(ComparisonOperation).getRightOperand().getValue() = "0"
+      )
+    )
+  }
+
+  /** Holds when a comparison expression exists. */
+  predicate compareWithOutZero() {
+    exists(Expr exp |
+      exp instanceof ComparisonOperation and
+      (
+        globalValueNumber(exp.getAChild*()) = globalValueNumber(this) or
+        hashCons(exp.getAChild*()) = hashCons(this)
+      )
+    )
+  }
+}
+
+from Expr exp
+where
+  exp instanceof UsingArithmeticInComparison and
+  not exp.(UsingArithmeticInComparison).workingWithValue() and
+  not exp.(UsingArithmeticInComparison).workingWithPointer() and
+  not exp.(UsingArithmeticInComparison).insideTheLoop() and
+  not exp.(UsingArithmeticInComparison).compareWithZero() and
+  exp.(UsingArithmeticInComparison).compareWithOutZero()
+  or
+  exists(WhileStmt wst | wst instanceof UsingWhileAfterWhile and exp = wst.getCondition())
+select exp, "this expression needs your attention"
diff --git a/...perimental/Security/CWE/CWE-691/InsufficientControlFlowManagementWhenUsingBitOperations.c b/...perimental/Security/CWE/CWE-691/InsufficientControlFlowManagementWhenUsingBitOperations.c
@@ -0,0 +1,4 @@
+if(len>0 & memset(buf,0,len)) return 1; // BAD: `memset` will be called regardless of the value of the `len` variable. moreover, one cannot be sure that it will happen after verification
+...
+if(len>0 && memset(buf,0,len)) return 1; // GOOD: `memset` will be called after the `len` variable has been checked.
+...
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		lgtm
		* The queries cpp/tainted-arithmetic, cpp/uncontrolled-arithmetic, and cpp/arithmetic-with-extreme-values have been improved to produce fewer false positives.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		codescanning
		* The 'Pointer to stack object used as return value' (cpp/return-stack-allocated-object) query has been deprecated, and any uses should be replaced with `Returning stack-allocated memory` (cpp/return-stack-allocated-memory).
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		lgtm,codescanning
		* The `exprMightOverflowPositively` and `exprMightOverflowNegatively` predicates from the `SimpleRangeAnalysis` library now recognize more expressions that might overflow.
-Original file line number
+Diff line change
@@ Expand Up @@
       MSDN Library: <a href="https://docs.microsoft.com/en-us/cpp/cpp/switch-statement-cpp">switch statement (C++)</a>
     </li>
     <li>
-      M. Henricson and E. Nyquist, <i>Industrial Strength C++</i>, Chapter 4: Control Flow, Rec 4.5. Prentice Hall PTR, 1997 (<a href="http://mongers.org/industrial-c++/">available online</a>).
+      M. Henricson and E. Nyquist, <i>Industrial Strength C++</i>, Chapter 4: Control Flow, Rec 4.5. Prentice Hall PTR, 1997 (<a href="https://web.archive.org/web/20190919025638/https://mongers.org/industrial-c++/">available online</a>).
     </li>
@@ Expand Down @@