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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /mozglue/misc/ImportDir.h
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mozglue/misc/ImportDir.h')
-rw-r--r--mozglue/misc/ImportDir.h94
1 files changed, 94 insertions, 0 deletions
diff --git a/mozglue/misc/ImportDir.h b/mozglue/misc/ImportDir.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/NativeNt.h"
+#include "mozilla/WinHeaderOnlyUtils.h"
+
+namespace mozilla {
+namespace detail {
+
+inline LauncherResult<nt::DataDirectoryEntry> GetImageDirectoryViaFileIo(
+ const nsAutoHandle& aImageFile, const uint32_t aOurImportDirectoryRva) {
+ OVERLAPPED ov = {};
+ ov.Offset = aOurImportDirectoryRva;
+
+ DWORD bytesRead;
+ nt::DataDirectoryEntry result;
+ if (!::ReadFile(aImageFile, &result, sizeof(result), &bytesRead, &ov) ||
+ bytesRead != sizeof(result)) {
+ return LAUNCHER_ERROR_FROM_LAST();
+ }
+
+ return result;
+}
+
+} // namespace detail
+
+/**
+ * This function ensures that the import directory of a loaded binary image
+ * matches the version that is found in the original file on disk. We do this
+ * to prevent tampering by third-party code.
+ *
+ * Yes, this function may perform file I/O on the critical path during
+ * startup. A mitigating factor here is that this function must be called
+ * immediately after creating a process using the image specified by
+ * |aFullImagePath|; by this point, the system has already paid the price of
+ * pulling the image file's contents into the page cache.
+ *
+ * @param aFullImagePath Wide-character string containing the absolute path
+ * to the binary whose import directory we are touching.
+ * @param aTransferMgr Encapsulating the transfer from the current process to
+ * the child process whose import table we are touching.
+ */
+inline LauncherVoidResult RestoreImportDirectory(
+ const wchar_t* aFullImagePath, nt::CrossExecTransferManager& aTransferMgr) {
+ uint32_t importDirEntryRva;
+ PIMAGE_DATA_DIRECTORY importDirEntry =
+ aTransferMgr.LocalPEHeaders().GetImageDirectoryEntryPtr(
+ IMAGE_DIRECTORY_ENTRY_IMPORT, &importDirEntryRva);
+ if (!importDirEntry) {
+ return LAUNCHER_ERROR_FROM_WIN32(ERROR_BAD_EXE_FORMAT);
+ }
+
+ nsAutoHandle file(::CreateFileW(aFullImagePath, GENERIC_READ, FILE_SHARE_READ,
+ nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
+ nullptr));
+ if (file.get() == INVALID_HANDLE_VALUE) {
+ return LAUNCHER_ERROR_FROM_LAST();
+ }
+
+ // Why do we use file I/O here instead of a memory mapping? The simple reason
+ // is that we do not want any kernel-mode drivers to start tampering with file
+ // contents under the belief that the file is being mapped for execution.
+ // Windows 8 supports creation of file mappings using the SEC_IMAGE_NO_EXECUTE
+ // flag, which may help to mitigate this, but we might as well just support
+ // a single implementation that works everywhere.
+ LauncherResult<nt::DataDirectoryEntry> realImportDirectory =
+ detail::GetImageDirectoryViaFileIo(file, importDirEntryRva);
+ if (realImportDirectory.isErr()) {
+ return realImportDirectory.propagateErr();
+ }
+
+ nt::DataDirectoryEntry toWrite = realImportDirectory.unwrap();
+
+ { // Scope for prot
+ AutoVirtualProtect prot = aTransferMgr.Protect(
+ importDirEntry, sizeof(IMAGE_DATA_DIRECTORY), PAGE_READWRITE);
+ if (!prot) {
+ return LAUNCHER_ERROR_FROM_MOZ_WINDOWS_ERROR(prot.GetError());
+ }
+
+ LauncherVoidResult writeResult = aTransferMgr.Transfer(
+ importDirEntry, &toWrite, sizeof(IMAGE_DATA_DIRECTORY));
+ if (writeResult.isErr()) {
+ return writeResult.propagateErr();
+ }
+ }
+
+ return Ok();
+}
+
+} // namespace mozilla