ci: drop LGTM stuff and move remaining bits into a new location

3 files changed, 180 insertions, 0 deletions

diff --git a/.github/codeql-queries/PotentiallyDangerousFunction.ql b/.github/codeql-queries/PotentiallyDangerousFunction.ql
new file mode 100644
index 0000000000..63fd14e75f
--- /dev/null
+++ b/.github/codeql-queries/PotentiallyDangerousFunction.ql
@@ -0,0 +1,59 @@
+/**
+ * vi: sw=2 ts=2 et syntax=ql:
+ *
+ * Borrowed from
+ * https://github.com/Semmle/ql/blob/master/cpp/ql/src/Security/CWE/CWE-676/PotentiallyDangerousFunction.ql
+ *
+ * @name Use of potentially dangerous function
+ * @description Certain standard library functions are dangerous to call.
+ * @id cpp/potentially-dangerous-function
+ * @kind problem
+ * @problem.severity error
+ * @precision high
+ * @tags reliability
+ *       security
+ */
+import cpp
+
+predicate potentiallyDangerousFunction(Function f, string message) {
+  (
+    f.getQualifiedName() = "fgets" and
+    message = "Call to fgets() is potentially dangerous. Use read_line() instead."
+  ) or (
+    f.getQualifiedName() = "strtok" and
+    message = "Call to strtok() is potentially dangerous. Use extract_first_word() instead."
+  ) or (
+    f.getQualifiedName() = "strsep" and
+    message = "Call to strsep() is potentially dangerous. Use extract_first_word() instead."
+  ) or (
+    f.getQualifiedName() = "dup" and
+    message = "Call to dup() is potentially dangerous. Use fcntl(fd, FD_DUPFD_CLOEXEC, 3) instead."
+  ) or (
+    f.getQualifiedName() = "htonl" and
+    message = "Call to htonl() is confusing. Use htobe32() instead."
+  ) or (
+    f.getQualifiedName() = "htons" and
+    message = "Call to htons() is confusing. Use htobe16() instead."
+  ) or (
+    f.getQualifiedName() = "ntohl" and
+    message = "Call to ntohl() is confusing. Use be32toh() instead."
+  ) or (
+    f.getQualifiedName() = "ntohs" and
+    message = "Call to ntohs() is confusing. Use be16toh() instead."
+  ) or (
+    f.getQualifiedName() = "strerror" and
+    message = "Call to strerror() is not thread-safe. Use strerror_r() or printf()'s %m format string instead."
+  ) or (
+    f.getQualifiedName() = "accept" and
+    message = "Call to accept() is not O_CLOEXEC-safe. Use accept4() instead."
+  ) or (
+    f.getQualifiedName() = "dirname" and
+    message = "Call dirname() is icky. Use path_extract_directory() instead."
+  )
+}
+
+from FunctionCall call, Function target, string message
+where
+  call.getTarget() = target and
+  potentiallyDangerousFunction(target, message)
+select call, message
diff --git a/.github/codeql-queries/UninitializedVariableWithCleanup.ql b/.github/codeql-queries/UninitializedVariableWithCleanup.ql
new file mode 100644
index 0000000000..6b3b62f8bc
--- /dev/null
+++ b/.github/codeql-queries/UninitializedVariableWithCleanup.ql
@@ -0,0 +1,110 @@
+/**
+ * vi: sw=2 ts=2 et syntax=ql:
+ *
+ * Based on cpp/uninitialized-local.
+ *
+ * @name Potentially uninitialized local variable using the cleanup attribute
+ * @description Running the cleanup handler on a possibly uninitialized variable
+ *              is generally a bad idea.
+ * @id cpp/uninitialized-local-with-cleanup
+ * @kind problem
+ * @problem.severity error
+ * @precision high
+ * @tags security
+ */
+
+import cpp
+import semmle.code.cpp.controlflow.StackVariableReachability
+
+/** Auxiliary predicate: List cleanup functions we want to explicitly ignore
+  * since they don't do anything illegal even when the variable is uninitialized
+  */
+predicate cleanupFunctionDenyList(string fun) {
+  fun = "erase_char"
+}
+
+/**
+ * A declaration of a local variable using __attribute__((__cleanup__(x)))
+ * that leaves the variable uninitialized.
+ */
+DeclStmt declWithNoInit(LocalVariable v) {
+  result.getADeclaration() = v and
+  not v.hasInitializer() and
+  /* The variable has __attribute__((__cleanup__(...))) set */
+  v.getAnAttribute().hasName("cleanup") and
+  /* Check if the cleanup function is not on a deny list */
+  not cleanupFunctionDenyList(v.getAnAttribute().getAnArgument().getValueText())
+}
+
+class UninitialisedLocalReachability extends StackVariableReachability {
+  UninitialisedLocalReachability() { this = "UninitialisedLocal" }
+
+  override predicate isSource(ControlFlowNode node, StackVariable v) { node = declWithNoInit(v) }
+
+  /* Note: _don't_ use the `useOfVarActual()` predicate here (and a couple of lines
+   * below), as it assumes that the callee always modifies the variable if
+   * it's passed to the function.
+   *
+   * i.e.:
+   * _cleanup_free char *x;
+   * fun(&x);
+   * puts(x);
+   *
+   * `useOfVarActual()` won't treat this an an uninitialized read even if the callee
+   * doesn't modify the argument, however, `useOfVar()` will
+   */
+  override predicate isSink(ControlFlowNode node, StackVariable v) { useOfVar(v, node) }
+
+  override predicate isBarrier(ControlFlowNode node, StackVariable v) {
+    // only report the _first_ possibly uninitialized use
+    useOfVar(v, node) or
+    (
+      /* If there's an return statement somewhere between the variable declaration
+       * and a possible definition, don't accept is as a valid initialization.
+       *
+       * E.g.:
+       * _cleanup_free_ char *x;
+       * ...
+       * if (...)
+       *    return;
+       * ...
+       * x = malloc(...);
+       *
+       * is not a valid initialization, since we might return from the function
+       * _before_ the actual iniitialization (emphasis on _might_, since we
+       * don't know if the return statement might ever evaluate to true).
+       */
+      definitionBarrier(v, node) and
+      not exists(ReturnStmt rs |
+                 /* The attribute check is "just" a complexity optimization */
+                 v.getFunction() = rs.getEnclosingFunction() and v.getAnAttribute().hasName("cleanup") |
+                 rs.getLocation().isBefore(node.getLocation())
+      )
+    )
+  }
+}
+
+pragma[noinline]
+predicate containsInlineAssembly(Function f) { exists(AsmStmt s | s.getEnclosingFunction() = f) }
+
+/**
+ * Auxiliary predicate: List common exceptions or false positives
+ * for this check to exclude them.
+ */
+VariableAccess commonException() {
+  // If the uninitialized use we've found is in a macro expansion, it's
+  // typically something like va_start(), and we don't want to complain.
+  result.getParent().isInMacroExpansion()
+  or
+  result.getParent() instanceof BuiltInOperation
+  or
+  // Finally, exclude functions that contain assembly blocks. It's
+  // anyone's guess what happens in those.
+  containsInlineAssembly(result.getEnclosingFunction())
+}
+
+from UninitialisedLocalReachability r, LocalVariable v, VariableAccess va
+where
+  r.reaches(_, v, va) and
+  not va = commonException()
+select va, "The variable $@ may not be initialized here, but has a cleanup handler.", v, v.getName()
diff --git a/.github/codeql-queries/qlpack.yml b/.github/codeql-queries/qlpack.yml
new file mode 100644
index 0000000000..a1a2dec6d6
--- /dev/null
+++ b/.github/codeql-queries/qlpack.yml
@@ -0,0 +1,11 @@
+---
+# vi: ts=2 sw=2 et syntax=yaml:
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+library: false
+name: systemd/cpp-queries
+version: 0.0.1
+dependencies:
+  codeql/cpp-all: "*"
+  codeql/suite-helpers: "*"
+extractor: cpp