diff --git a/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp b/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp --- a/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp @@ -20,6 +20,7 @@ #include "CloexecInotifyInitCheck.h" #include "CloexecMemfdCreateCheck.h" #include "CloexecOpenCheck.h" +#include "CloexecPipe2Check.h" #include "CloexecSocketCheck.h" #include "ComparisonInTempFailureRetryCheck.h" @@ -49,6 +50,7 @@ CheckFactories.registerCheck( "android-cloexec-memfd-create"); CheckFactories.registerCheck("android-cloexec-open"); + CheckFactories.registerCheck("android-cloexec-pipe2"); CheckFactories.registerCheck("android-cloexec-socket"); CheckFactories.registerCheck( "android-comparison-in-temp-failure-retry"); diff --git a/clang-tools-extra/clang-tidy/android/CMakeLists.txt b/clang-tools-extra/clang-tidy/android/CMakeLists.txt --- a/clang-tools-extra/clang-tidy/android/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/android/CMakeLists.txt @@ -14,6 +14,7 @@ CloexecInotifyInitCheck.cpp CloexecMemfdCreateCheck.cpp CloexecOpenCheck.cpp + CloexecPipe2Check.cpp CloexecSocketCheck.cpp ComparisonInTempFailureRetryCheck.cpp diff --git a/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.h b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.h new file mode 100644 --- /dev/null +++ b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.h @@ -0,0 +1,34 @@ +//===--- CloexecPipe2Check.h - clang-tidy------------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_PIPE2_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_PIPE2_H + +#include "CloexecCheck.h" + +namespace clang { +namespace tidy { +namespace android { + +/// Finds code that uses pipe2() without using the O_CLOEXEC flag. +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-pipe2.html +class CloexecPipe2Check : public CloexecCheck { +public: + CloexecPipe2Check(StringRef Name, ClangTidyContext *Context) + : CloexecCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace android +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_PIPE2_H diff --git a/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.cpp b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.cpp new file mode 100644 --- /dev/null +++ b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.cpp @@ -0,0 +1,33 @@ +//===--- CloexecPipe2Check.cpp - clang-tidy--------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "CloexecPipe2Check.h" +#include "../utils/ASTUtils.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { +namespace android { + +void CloexecPipe2Check::registerMatchers(MatchFinder *Finder) { + registerMatchersImpl(Finder, + functionDecl(returns(isInteger()), hasName("pipe2"), + hasParameter(0, hasType(pointsTo(isInteger()))), + hasParameter(1, hasType(isInteger())))); +} + +void CloexecPipe2Check::check(const MatchFinder::MatchResult &Result) { + insertMacroFlag(Result, /*MacroFlag=*/"O_CLOEXEC", /*ArgPos=*/1); +} + +} // namespace android +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst --- a/clang-tools-extra/docs/ReleaseNotes.rst +++ b/clang-tools-extra/docs/ReleaseNotes.rst @@ -101,6 +101,12 @@ Finds and fixes ``absl::Time`` subtraction expressions to do subtraction in the Time domain instead of the numeric domain. +- New :doc:`android-cloexec-pipe + ` check. + + Checks if the required file flag ``O_CLOEXEC`` is present in the argument of + ``pipe2()``. + - New :doc:`bugprone-unhandled-self-assignment ` check. diff --git a/clang-tools-extra/docs/clang-tidy/checks/android-cloexec-pipe2.rst b/clang-tools-extra/docs/clang-tidy/checks/android-cloexec-pipe2.rst new file mode 100644 --- /dev/null +++ b/clang-tools-extra/docs/clang-tidy/checks/android-cloexec-pipe2.rst @@ -0,0 +1,19 @@ +.. title:: clang-tidy - android-cloexec-pipe2 + +android-cloexec-pipe2 +===================== + +Checks if the required file flag ``O_CLOEXEC`` is present in the argument of +``pipe2()``. ``pipe2()`` should include ``O_CLOEXEC`` in its type argument to +avoid the file descriptor leakage. Without this flag, an opened sensitive file +would remain open across a ``fork``+``exec`` to a lower-privileged SELinux domain. + +Examples: + +.. code-block:: c++ + + pipe2(pipefd, O_NONBLOCK); + + // becomes + + pipe2(pipefd, O_CLOEXEC); diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst --- a/clang-tools-extra/docs/clang-tidy/checks/list.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst @@ -32,6 +32,7 @@ android-cloexec-inotify-init1 android-cloexec-memfd-create android-cloexec-open + android-cloexec-pipe2 android-cloexec-socket android-comparison-in-temp-failure-retry boost-use-to-string diff --git a/clang-tools-extra/test/clang-tidy/android-cloexec-pipe2.cpp b/clang-tools-extra/test/clang-tidy/android-cloexec-pipe2.cpp new file mode 100644 --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/android-cloexec-pipe2.cpp @@ -0,0 +1,68 @@ +// RUN: %check_clang_tidy %s android-cloexec-pipe2 %t + +#define O_NONBLOCK 1 +#define __O_CLOEXEC 3 +#define O_CLOEXEC __O_CLOEXEC +#define TEMP_FAILURE_RETRY(exp) \ + ({ \ + int _rc; \ + do { \ + _rc = (exp); \ + } while (_rc == -1); \ + }) +#define NULL 0 + +extern "C" int pipe2(int pipefd[2], int flags); + +void a() { + int pipefd[2]; + pipe2(pipefd, O_NONBLOCK); + // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: 'pipe2' should use O_CLOEXEC where possible [android-cloexec-pipe2] + // CHECK-FIXES: pipe2(pipefd, O_NONBLOCK | O_CLOEXEC); + TEMP_FAILURE_RETRY(pipe2(pipefd, O_NONBLOCK)); + // CHECK-MESSAGES: :[[@LINE-1]]:46: warning: 'pipe2' + // CHECK-FIXES: TEMP_FAILURE_RETRY(pipe2(pipefd, O_NONBLOCK | O_CLOEXEC)); +} + +void f() { + int pipefd[2]; + pipe2(pipefd, 3); + // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'pipe2' + // CHECK-FIXES: pipe2(pipefd, 3 | O_CLOEXEC); + TEMP_FAILURE_RETRY(pipe2(pipefd, 3)); + // CHECK-MESSAGES: :[[@LINE-1]]:37: warning: 'pipe2' + // CHECK-FIXES: TEMP_FAILURE_RETRY(pipe2(pipefd, 3 | O_CLOEXEC)); + + int flag = O_NONBLOCK; + pipe2(pipefd, flag); + TEMP_FAILURE_RETRY(pipe2(pipefd, flag)); +} + +namespace i { +int pipe2(int pipefd[2], int flags); + +void d() { + int pipefd[2]; + pipe2(pipefd, O_NONBLOCK); + TEMP_FAILURE_RETRY(pipe2(pipefd, O_NONBLOCK)); +} + +} // namespace i + +void e() { + int pipefd[2]; + pipe2(pipefd, O_CLOEXEC); + TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC)); + pipe2(pipefd, O_NONBLOCK | O_CLOEXEC); + TEMP_FAILURE_RETRY(pipe2(pipefd, O_NONBLOCK | O_CLOEXEC)); +} + +class G { +public: + int pipe2(int pipefd[2], int flags); + void d() { + int pipefd[2]; + pipe2(pipefd, O_NONBLOCK); + TEMP_FAILURE_RETRY(pipe2(pipefd, O_NONBLOCK)); + } +};