davezarzycki created this revision.
davezarzycki added reviewers: compnerd, aprantl, jakehehrlich, espindola,
respindola, ilya-biryukov, pcc, sammccall.
davezarzycki added a project: LLVM.
Herald added subscribers: cfe-commits, hiraditya.
Herald added a project: clang.
Naive usage of shared temporary directories in Unix is a classic security
problem. Let's deprecate two APIs that enable unsafe code and encourage people
to use `createUniqueFile` or `createUniqueDirectory` instead.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D82259
Files:
clang/lib/Driver/ToolChains/Clang.cpp
llvm/include/llvm/Support/FileSystem.h
llvm/include/llvm/Support/Path.h
llvm/lib/Support/Path.cpp
Index: llvm/lib/Support/Path.cpp
===================================================================
--- llvm/lib/Support/Path.cpp
+++ llvm/lib/Support/Path.cpp
@@ -164,6 +164,41 @@
FS_Name
};
+// Avoid a deprecation warning by moving the createUniquePath body here.
+static void _createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
+ bool MakeAbsolute) {
+ SmallString<128> ModelStorage;
+ Model.toVector(ModelStorage);
+
+ if (MakeAbsolute) {
+ // Make model absolute by prepending a temp directory if it's not already.
+ if (!sys::path::is_absolute(Twine(ModelStorage))) {
+ SmallString<128> TDir;
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#endif
+ sys::path::system_temp_directory(true, TDir);
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+ sys::path::append(TDir, Twine(ModelStorage));
+ ModelStorage.swap(TDir);
+ }
+ }
+
+ ResultPath = ModelStorage;
+ ResultPath.push_back(0);
+ ResultPath.pop_back();
+
+ // Replace '%' with random chars.
+ for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {
+ if (ModelStorage[i] == '%')
+ ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
+ }
+}
+
+
static std::error_code
createUniqueEntity(const Twine &Model, int &ResultFD,
SmallVectorImpl<char> &ResultPath, bool MakeAbsolute,
@@ -176,7 +211,7 @@
// Checking which is racy, so we try a number of times, then give up.
std::error_code EC;
for (int Retries = 128; Retries > 0; --Retries) {
- sys::fs::createUniquePath(Model, ResultPath, MakeAbsolute);
+ _createUniquePath(Model, ResultPath, MakeAbsolute);
// Try to open + create the file.
switch (Type) {
case FS_File: {
@@ -777,29 +812,8 @@
}
void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
- bool MakeAbsolute) {
- SmallString<128> ModelStorage;
- Model.toVector(ModelStorage);
-
- if (MakeAbsolute) {
- // Make model absolute by prepending a temp directory if it's not already.
- if (!sys::path::is_absolute(Twine(ModelStorage))) {
- SmallString<128> TDir;
- sys::path::system_temp_directory(true, TDir);
- sys::path::append(TDir, Twine(ModelStorage));
- ModelStorage.swap(TDir);
- }
- }
-
- ResultPath = ModelStorage;
- ResultPath.push_back(0);
- ResultPath.pop_back();
-
- // Replace '%' with random chars.
- for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {
- if (ModelStorage[i] == '%')
- ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
- }
+ bool MakeAbsolute) {
+ return _createUniquePath(Model, ResultPath, MakeAbsolute);
}
std::error_code createUniqueFile(const Twine &Model, int &ResultFd,
Index: llvm/include/llvm/Support/Path.h
===================================================================
--- llvm/include/llvm/Support/Path.h
+++ llvm/include/llvm/Support/Path.h
@@ -363,7 +363,10 @@
/// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.
///
/// @param result Holds the resulting path name.
-void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);
+LLVM_ATTRIBUTE_DEPRECATED(
+void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result),
+ "Only meant for debugging due to trivial security problems"
+);
/// Get the user's home directory.
///
Index: llvm/include/llvm/Support/FileSystem.h
===================================================================
--- llvm/include/llvm/Support/FileSystem.h
+++ llvm/include/llvm/Support/FileSystem.h
@@ -800,8 +800,11 @@
/// @param Model Name to base unique path off of.
/// @param ResultPath Set to the file's path.
/// @param MakeAbsolute Whether to use the system temp directory.
-void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
- bool MakeAbsolute);
+LLVM_ATTRIBUTE_DEPRECATED(
+ void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
+ bool MakeAbsolute),
+ "Use createUniqueFile() or createUniqueDirectory()"
+);
/// Create a uniquely named file.
///
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -733,38 +733,6 @@
}
}
-static void appendUserToPath(SmallVectorImpl<char> &Result) {
-#ifdef LLVM_ON_UNIX
- const char *Username = getenv("LOGNAME");
-#else
- const char *Username = getenv("USERNAME");
-#endif
- if (Username) {
- // Validate that LoginName can be used in a path, and get its length.
- size_t Len = 0;
- for (const char *P = Username; *P; ++P, ++Len) {
- if (!clang::isAlphanumeric(*P) && *P != '_') {
- Username = nullptr;
- break;
- }
- }
-
- if (Username && Len > 0) {
- Result.append(Username, Username + Len);
- return;
- }
- }
-
-// Fallback to user id.
-#ifdef LLVM_ON_UNIX
- std::string UID = llvm::utostr(getuid());
-#else
- // FIXME: Windows seems to have an 'SID' that might work.
- std::string UID = "9999";
-#endif
- Result.append(UID.begin(), UID.end());
-}
-
static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C,
const Driver &D, const InputInfo &Output,
const ArgList &Args,
@@ -3203,9 +3171,8 @@
}
void Driver::getDefaultModuleCachePath(SmallVectorImpl<char> &Result) {
- llvm::sys::path::system_temp_directory(/*erasedOnReboot=*/false, Result);
- llvm::sys::path::append(Result, "org.llvm.clang.");
- appendUserToPath(Result);
+ llvm::sys::path::home_directory(Result);
+ llvm::sys::path::append(Result, ".org.llvm.clang");
llvm::sys::path::append(Result, "ModuleCache");
}
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