diff --git a/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp b/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp index fe9330dd2d22..33c12d1cc05f 100644 --- a/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp @@ -10,6 +10,7 @@ #include "../ClangTidy.h" #include "../ClangTidyModule.h" #include "../ClangTidyModuleRegistry.h" +#include "CloexecAccept4Check.h" #include "CloexecAcceptCheck.h" #include "CloexecCreatCheck.h" #include "CloexecDupCheck.h" @@ -30,6 +31,7 @@ namespace android { class AndroidModule : public ClangTidyModule { public: void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override { + CheckFactories.registerCheck("android-cloexec-accept4"); CheckFactories.registerCheck("android-cloexec-accept"); CheckFactories.registerCheck("android-cloexec-creat"); CheckFactories.registerCheck("android-cloexec-dup"); diff --git a/clang-tools-extra/clang-tidy/android/CMakeLists.txt b/clang-tools-extra/clang-tidy/android/CMakeLists.txt index b902542f11c2..15228401d1a0 100644 --- a/clang-tools-extra/clang-tidy/android/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/android/CMakeLists.txt @@ -2,6 +2,7 @@ set(LLVM_LINK_COMPONENTS support) add_clang_library(clangTidyAndroidModule AndroidTidyModule.cpp + CloexecAccept4Check.cpp CloexecAcceptCheck.cpp CloexecCheck.cpp CloexecCreatCheck.cpp diff --git a/clang-tools-extra/clang-tidy/android/CloexecAccept4Check.cpp b/clang-tools-extra/clang-tidy/android/CloexecAccept4Check.cpp new file mode 100644 index 000000000000..a86eedd85116 --- /dev/null +++ b/clang-tools-extra/clang-tidy/android/CloexecAccept4Check.cpp @@ -0,0 +1,40 @@ +//===--- CloexecAccept4Check.cpp - clang-tidy------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "CloexecAccept4Check.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 CloexecAccept4Check::registerMatchers(MatchFinder *Finder) { + auto SockAddrPointerType = + hasType(pointsTo(recordDecl(isStruct(), hasName("sockaddr")))); + auto SockLenPointerType = hasType(pointsTo(namedDecl(hasName("socklen_t")))); + + registerMatchersImpl(Finder, + functionDecl(returns(isInteger()), hasName("accept4"), + hasParameter(0, hasType(isInteger())), + hasParameter(1, SockAddrPointerType), + hasParameter(2, SockLenPointerType), + hasParameter(3, hasType(isInteger())))); +} + +void CloexecAccept4Check::check(const MatchFinder::MatchResult &Result) { + insertMacroFlag(Result, /*MarcoFlag=*/"SOCK_CLOEXEC", /*ArgPos=*/3); +} + +} // namespace android +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/clang-tidy/android/CloexecAccept4Check.h b/clang-tools-extra/clang-tidy/android/CloexecAccept4Check.h new file mode 100644 index 000000000000..0cf32152df38 --- /dev/null +++ b/clang-tools-extra/clang-tidy/android/CloexecAccept4Check.h @@ -0,0 +1,35 @@ +//===--- CloexecAccept4Check.h - clang-tidy----------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_ACCEPT4_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_ACCEPT4_H + +#include "CloexecCheck.h" + +namespace clang { +namespace tidy { +namespace android { + +/// Finds code that uses accept4() without using the SOCK_CLOEXEC flag. +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-accept4.html +class CloexecAccept4Check : public CloexecCheck { +public: + CloexecAccept4Check(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_ACCEPT4_H diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst index 93d06b1da0d0..7d08d29b3f0a 100644 --- a/clang-tools-extra/docs/ReleaseNotes.rst +++ b/clang-tools-extra/docs/ReleaseNotes.rst @@ -75,6 +75,12 @@ Improvements to clang-tidy Detects usage of ``accept()``. +- New `android-cloexec-accept4 + `_ check + + Checks if the required file flag ``SOCK_CLOEXEC`` is present in the argument of + ``accept4()``. + - New `android-cloexec-dup `_ check diff --git a/clang-tools-extra/docs/clang-tidy/checks/android-cloexec-accept4.rst b/clang-tools-extra/docs/clang-tidy/checks/android-cloexec-accept4.rst new file mode 100644 index 000000000000..1633395d8f6a --- /dev/null +++ b/clang-tools-extra/docs/clang-tidy/checks/android-cloexec-accept4.rst @@ -0,0 +1,18 @@ +.. title:: clang-tidy - android-cloexec-accept4 + +android-cloexec-accept4 +======================= + +``accept4()`` should include ``SOCK_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++ + + accept4(sockfd, addr, addrlen, SOCK_NONBLOCK); + + // becomes + + accept4(sockfd, addr, addrlen, SOCK_NONBLOCK | SOCK_CLOEXEC); diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst index c386d0a9e830..9f04fc424fef 100644 --- a/clang-tools-extra/docs/clang-tidy/checks/list.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst @@ -5,6 +5,7 @@ Clang-Tidy Checks .. toctree:: android-cloexec-accept + android-cloexec-accept4 android-cloexec-creat android-cloexec-dup android-cloexec-fopen diff --git a/clang-tools-extra/test/clang-tidy/android-cloexec-accept4.cpp b/clang-tools-extra/test/clang-tidy/android-cloexec-accept4.cpp new file mode 100644 index 000000000000..448d4a9f6404 --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/android-cloexec-accept4.cpp @@ -0,0 +1,66 @@ +// RUN: %check_clang_tidy %s android-cloexec-accept4 %t + +typedef int socklen_t; +struct sockaddr {}; + +#define SOCK_NONBLOCK 1 +#define __O_CLOEXEC 3 +#define SOCK_CLOEXEC __O_CLOEXEC +#define TEMP_FAILURE_RETRY(exp) \ + ({ \ + int _rc; \ + do { \ + _rc = (exp); \ + } while (_rc == -1); \ + }) +#define NULL 0 + +extern "C" int accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags); + +void a() { + accept4(0, NULL, NULL, SOCK_NONBLOCK); + // CHECK-MESSAGES: :[[@LINE-1]]:39: warning: 'accept4' should use SOCK_CLOEXEC where possible [android-cloexec-accept4] + // CHECK-FIXES: accept4(0, NULL, NULL, SOCK_NONBLOCK | SOCK_CLOEXEC); + TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, SOCK_NONBLOCK)); + // CHECK-MESSAGES: :[[@LINE-1]]:58: warning: 'accept4' + // CHECK-FIXES: TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, SOCK_NONBLOCK | SOCK_CLOEXEC)); +} + +void f() { + accept4(0, NULL, NULL, 3); + // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: 'accept4' + // CHECK-FIXES: accept4(0, NULL, NULL, 3 | SOCK_CLOEXEC); + TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, 3)); + // CHECK-MESSAGES: :[[@LINE-1]]:46: warning: 'accept4' + // CHECK-FIXES: TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, 3 | SOCK_CLOEXEC)); + + int flag = SOCK_NONBLOCK; + accept4(0, NULL, NULL, flag); + TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, flag)); +} + +namespace i { +int accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags); + +void d() { + accept4(0, NULL, NULL, SOCK_NONBLOCK); + TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, SOCK_NONBLOCK)); +} + +} // namespace i + +void e() { + accept4(0, NULL, NULL, SOCK_CLOEXEC); + TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, SOCK_CLOEXEC)); + accept4(0, NULL, NULL, SOCK_NONBLOCK | SOCK_CLOEXEC); + TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, SOCK_NONBLOCK | SOCK_CLOEXEC)); +} + +class G { +public: + int accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags); + void d() { + accept4(0, NULL, NULL, SOCK_NONBLOCK); + TEMP_FAILURE_RETRY(accept4(0, NULL, NULL, SOCK_NONBLOCK)); + } +};