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Bug 1688452 - Retrofit nsExpatDriver to use RLBoxed libexpat r=tjr,peterv,bholley,glandium

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Differential Revision: https://phabricator.services.mozilla.com/D104658
This commit is contained in:
Deian Stefan 2021-11-19 06:08:36 +00:00
parent eef21610c6
commit 76c5d8907d
18 changed files with 805 additions and 216 deletions
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2
config/recurse.mk
View File

@ -217,7 +217,7 @@ endif
ifdef MOZ_USING_WASM_SANDBOXING
security/rlbox/target-objects: config/external/wasm2c_sandbox_compiler/host
security/rlbox/target: security/rlbox/target-objects
dom/media/ogg/target-objects extensions/spellcheck/hunspell/glue/target-objects gfx/thebes/target-objects: security/rlbox/target-objects
dom/media/ogg/target-objects extensions/spellcheck/hunspell/glue/target-objects gfx/thebes/target-objects parser/expat/target-objects parser/htmlparser/target-objects: security/rlbox/target-objects
endif
# Most things are built during compile (target/host), but some things happen during export

1
layout/build/moz.build
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@ -51,6 +51,7 @@ LOCAL_INCLUDES += [
"/js/xpconnect/src",
"/netwerk/base",
"/netwerk/cookie",
"/parser/htmlparser",
"/toolkit/components/sessionstore",
"/view",
]

4
layout/build/nsLayoutStatics.cpp
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@ -128,6 +128,8 @@
#include "RestoreTabContentObserver.h"
#include "mozilla/intl/nsComplexBreaker.h"
#include "nsRLBoxExpatDriver.h"
using namespace mozilla;
using namespace mozilla::net;
using namespace mozilla::dom;
@ -294,6 +296,8 @@ nsresult nsLayoutStatics::Initialize() {
ComplexBreaker::Initialize();
RLBoxExpatSandboxPool::Initialize();
return NS_OK;
}

17
parser/expat/expat_config.h
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@ -6,18 +6,11 @@
#ifndef __expat_config_h__
#define __expat_config_h__
#define MOZ_UNICODE
#include "nspr.h"
#ifdef IS_LITTLE_ENDIAN
#define BYTEORDER 1234
#else
#define BYTEORDER 4321
#endif /* IS_LITTLE_ENDIAN */
#if PR_BYTES_PER_INT != 4
#define int int32_t
#endif /* PR_BYTES_PER_INT != 4 */
#ifdef MOZ_IN_WASM_SANDBOX
# include "expat_config_rlbox.h"
#else
# include "expat_config_moz.h"
#endif
/* Other Mozilla code relies on memmove already, so we assume it's available */
#define HAVE_MEMMOVE 1

22
parser/expat/expat_config_moz.h Normal file
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@ -0,0 +1,22 @@
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 http://mozilla.org/MPL/2.0/. */
#ifndef __expat_config_moz_h__
#define __expat_config_moz_h__
#define MOZ_UNICODE
#include "nspr.h"
#ifdef IS_LITTLE_ENDIAN
#define BYTEORDER 1234
#else
#define BYTEORDER 4321
#endif /* IS_LITTLE_ENDIAN */
#if PR_BYTES_PER_INT != 4
#define int int32_t
#endif /* PR_BYTES_PER_INT != 4 */
#endif /* __expat_config_moz_h__ */

20
parser/expat/expat_config_rlbox.h Normal file
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@ -0,0 +1,20 @@
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 http://mozilla.org/MPL/2.0/. */
#ifndef __expat_config_rlbox_h__
#define __expat_config_rlbox_h__
/* Wasm is little endian */
#define BYTEORDER 1234
/* We don't redefine int as int32_t for our 32-bit Wasm machine. */
#ifdef __cplusplus
static_assert(sizeof(int) == sizeof(int32_t), "Expected int and int32_t to be of same size.");
#endif
/* We don't need to nor want to expose getpid() to expat */
#define getpid() 0
#endif /* __expat_config_rlbox_h__ */

11
parser/expat/lib/moz.build
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@ -4,17 +4,16 @@
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
include("sources.mozbuild")
EXPORTS += [
'expat.h',
'expat_external.h',
]
SOURCES += [
'xmlparse.c',
'xmlrole.c',
'xmltok.c',
]
SOURCES += expat_sources
FINAL_LIBRARY = 'gkmedias'
DEFINES['HAVE_EXPAT_CONFIG_H'] = True
for k, v in expat_defines:
DEFINES[k] = v

15
parser/expat/lib/sources.mozbuild Normal file
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@ -0,0 +1,15 @@
# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
# vim: set filetype=python:
# 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 http://mozilla.org/MPL/2.0/.
expat_sources = [
'xmlparse.c',
'xmlrole.c',
'xmltok.c',
]
expat_defines = [
('HAVE_EXPAT_CONFIG_H', True)
]

7
parser/expat/moz.build
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@ -11,5 +11,12 @@ DIRS += ['lib']
EXPORTS += [
'expat_config.h',
'expat_config_moz.h',
'expat_config_rlbox.h',
'rlbox_expat.h',
'rlbox_expat_types.h',
]
LOCAL_INCLUDES += [
'!/security/rlbox',
]

28
parser/expat/rlbox_expat.h Normal file
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@ -0,0 +1,28 @@
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 http://mozilla.org/MPL/2.0/. */
#ifndef PARSER_HTML_RLBOX_EXPAT_H_
#define PARSER_HTML_RLBOX_EXPAT_H_
#include "rlbox_expat_types.h"
// Load general firefox configuration of RLBox
#include "mozilla/rlbox/rlbox_config.h"
#ifdef MOZ_WASM_SANDBOXING_EXPAT
// Include the generated header file so that we are able to resolve the symbols
// in the wasm binary
# include "rlbox.wasm.h"
# define RLBOX_USE_STATIC_CALLS() rlbox_wasm2c_sandbox_lookup_symbol
# include "mozilla/rlbox/rlbox_wasm2c_sandbox.hpp"
#else
// Extra configuration for no-op sandbox
# define RLBOX_USE_STATIC_CALLS() rlbox_noop_sandbox_lookup_symbol
# include "mozilla/rlbox/rlbox_noop_sandbox.hpp"
#endif
#include "mozilla/rlbox/rlbox.hpp"
#endif

18
parser/expat/rlbox_expat_types.h Normal file
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@ -0,0 +1,18 @@
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 http://mozilla.org/MPL/2.0/. */
#ifndef PARSER_HTML_RLBOX_EXPAT_TYPES_H_
#define PARSER_HTML_RLBOX_EXPAT_TYPES_H_
#include <stddef.h>
#include "mozilla/rlbox/rlbox_types.hpp"
#ifdef MOZ_WASM_SANDBOXING_EXPAT
RLBOX_DEFINE_BASE_TYPES_FOR(expat, wasm2c)
#else
RLBOX_DEFINE_BASE_TYPES_FOR(expat, noop)
#endif
#endif

5
parser/htmlparser/moz.build
View File

@ -29,6 +29,7 @@ EXPORTS += [
"nsParserBase.h",
"nsParserCIID.h",
"nsParserConstants.h",
"nsRLBoxExpatDriver.h",
"nsScannerString.h",
]
@ -57,4 +58,8 @@ FINAL_LIBRARY = "xul"
if CONFIG["CC_TYPE"] in ("clang", "gcc"):
CXXFLAGS += ["-Wno-error=shadow"]
LOCAL_INCLUDES += [
"!/security/rlbox",
]
REQUIRES_UNIFIED_BUILD = True

751
parser/htmlparser/nsExpatDriver.cpp
View File

@ -34,6 +34,10 @@
#include "mozilla/Telemetry.h"
#include "mozilla/TelemetryComms.h"
#include "nsThreadUtils.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Logging.h"
using mozilla::fallible;
@ -51,103 +55,217 @@ static mozilla::LazyLogModule gExpatDriverLog("expatdriver");
// https://chromium.googlesource.com/chromium/src/+/f464165c1dedff1c955d3c051c5a9a1c6a0e8f6b/third_party/WebKit/Source/core/xml/parser/XMLDocumentParser.cpp#85).
static const uint16_t sMaxXMLTreeDepth = 5000;
/***************************** RLBOX HELPERS ********************************/
// Helpers for calling sandboxed expat functions in handlers
#define RLBOX_EXPAT_SAFE_CALL(foo, verifier, ...) \
aSandbox.invoke_sandbox_function(foo, self->mExpatParser, ##__VA_ARGS__) \
.copy_and_verify(verifier)
#define RLBOX_EXPAT_SAFE_MCALL(foo, verifier, ...) \
Sandbox() \
->invoke_sandbox_function(foo, mExpatParser, ##__VA_ARGS__) \
.copy_and_verify(verifier)
#define RLBOX_EXPAT_MCALL(foo, ...) \
Sandbox()->invoke_sandbox_function(foo, mExpatParser, ##__VA_ARGS__)
/* safe_unverified is used whenever it's safe to not use a validator */
template <typename T>
static T safe_unverified(T val) {
return val;
}
/* status_verifier is a type validator for XML_Status */
inline enum XML_Status status_verifier(enum XML_Status s) {
MOZ_RELEASE_ASSERT(s >= XML_STATUS_ERROR && s <= XML_STATUS_SUSPENDED,
"unexpected status code");
return s;
}
/* error_verifier is a type validator for XML_Error */
inline enum XML_Error error_verifier(enum XML_Error code) {
MOZ_RELEASE_ASSERT(
code >= XML_ERROR_NONE && code <= XML_ERROR_INVALID_ARGUMENT,
"unexpected XML error code");
return code;
}
/* We use unverified_xml_string to just expose sandbox expat strings to Firefox
* without any validation. On 64-bit we have guard pages at the sandbox
* boundary; on 32-bit we don't and a string could be used to read beyond the
* sandbox boundary. In our attacker model this is okay (the attacker can just
* Spectre).
*
* Nevertheless, we should try to add strings validators to the consumer code
* of expat whenever we have some semantics. At the very lest we should make
* sure that the strings are never written to. Bug 1693991 tracks this.
*/
static const XML_Char* unverified_xml_string(uintptr_t ptr) {
return reinterpret_cast<const XML_Char*>(ptr);
}
/* The TransferBuffer class is used to copy (or directly expose in the
* noop-sandbox case) buffers into the sandbox that are automatically freed
* when the TransferBuffer is out of scope. NOTE: The sandbox lifetime must
* outlive all of its TransferBuffers.
*/
template <typename T>
class MOZ_STACK_CLASS TransferBuffer {
public:
TransferBuffer() = delete;
TransferBuffer(rlbox_sandbox_expat* aSandbox, const T* aBuf,
const size_t aLen)
: mSandbox(aSandbox), mCopied(false), mBuf(nullptr) {
if (aBuf) {
mBuf = rlbox::copy_memory_or_grant_access(
*mSandbox, aBuf, aLen * sizeof(T), false, mCopied);
}
};
~TransferBuffer() {
if (mCopied) {
mSandbox->free_in_sandbox(mBuf);
}
};
tainted_expat<const T*> operator*() const { return mBuf; };
private:
rlbox_sandbox_expat* mSandbox;
bool mCopied;
tainted_expat<const T*> mBuf;
};
/*************************** END RLBOX HELPERS ******************************/
/***************************** EXPAT CALL BACKS ******************************/
// The callback handlers that get called from the expat parser.
static void Driver_HandleXMLDeclaration(void* aUserData,
const XML_Char* aVersion,
const XML_Char* aEncoding,
int aStandalone) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aUserData);
driver->HandleXMLDeclaration(aVersion, aEncoding, aStandalone);
}
static void Driver_HandleXMLDeclaration(
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> /* aUserData */,
tainted_expat<const XML_Char*> aVersion,
tainted_expat<const XML_Char*> aEncoding, tainted_expat<int> aStandalone) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
int standalone = aStandalone.copy_and_verify([&](auto a) {
// Standalone argument can be -1, 0, or 1 (see
// /parser/expat/lib/expat.h#185)
MOZ_RELEASE_ASSERT(a >= -1 && a <= 1, "Unexpected standalone parameter");
return a;
});
const auto* version = aVersion.copy_and_verify_address(unverified_xml_string);
const auto* encoding =
aEncoding.copy_and_verify_address(unverified_xml_string);
driver->HandleXMLDeclaration(version, encoding, standalone);
}
static void Driver_HandleCharacterData(void* aUserData, const XML_Char* aData,
int aLength) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aUserData);
driver->HandleCharacterData(aData, uint32_t(aLength));
}
static void Driver_HandleCharacterData(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> /* aUserData */,
tainted_expat<const XML_Char*> aData,
tainted_expat<int> aLength) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
// aData is not null terminated; even with bad length we will not span beyond
// sandbox boundary
uint32_t length =
static_cast<uint32_t>(aLength.copy_and_verify(safe_unverified<int>));
const auto* data = aData.unverified_safe_pointer_because(
length, "Only care that the data is within sandbox boundary.");
driver->HandleCharacterData(data, length);
}
static void Driver_HandleComment(void* aUserData, const XML_Char* aName) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
static_cast<nsExpatDriver*>(aUserData)->HandleComment(aName);
}
static void Driver_HandleComment(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> /* aUserData */,
tainted_expat<const XML_Char*> aName) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
const auto* name = aName.copy_and_verify_address(unverified_xml_string);
driver->HandleComment(name);
}
static void Driver_HandleProcessingInstruction(void* aUserData,
const XML_Char* aTarget,
const XML_Char* aData) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aUserData);
driver->HandleProcessingInstruction(aTarget, aData);
}
static void Driver_HandleProcessingInstruction(
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> /* aUserData */,
tainted_expat<const XML_Char*> aTarget,
tainted_expat<const XML_Char*> aData) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
const auto* target = aTarget.copy_and_verify_address(unverified_xml_string);
const auto* data = aData.copy_and_verify_address(unverified_xml_string);
driver->HandleProcessingInstruction(target, data);
}
static void Driver_HandleDefault(void* aUserData, const XML_Char* aData,
int aLength) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aUserData);
driver->HandleDefault(aData, uint32_t(aLength));
}
static void Driver_HandleDefault(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> /* aUserData */,
tainted_expat<const XML_Char*> aData,
tainted_expat<int> aLength) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
// aData is not null terminated; even with bad length we will not span
// beyond sandbox boundary
uint32_t length =
static_cast<uint32_t>(aLength.copy_and_verify(safe_unverified<int>));
const auto* data = aData.unverified_safe_pointer_because(
length, "Only care that the data is within sandbox boundary.");
driver->HandleDefault(data, length);
}
static void Driver_HandleStartCdataSection(void* aUserData) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
static_cast<nsExpatDriver*>(aUserData)->HandleStartCdataSection();
}
static void Driver_HandleStartCdataSection(
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> /* aUserData */) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
driver->HandleStartCdataSection();
}
static void Driver_HandleEndCdataSection(void* aUserData) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
static_cast<nsExpatDriver*>(aUserData)->HandleEndCdataSection();
}
static void Driver_HandleEndCdataSection(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> /* aUserData */) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
driver->HandleEndCdataSection();
}
static void Driver_HandleStartDoctypeDecl(void* aUserData,
const XML_Char* aDoctypeName,
const XML_Char* aSysid,
const XML_Char* aPubid,
int aHasInternalSubset) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
static_cast<nsExpatDriver*>(aUserData)->HandleStartDoctypeDecl(
aDoctypeName, aSysid, aPubid, !!aHasInternalSubset);
}
static void Driver_HandleStartDoctypeDecl(
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> /* aUserData */,
tainted_expat<const XML_Char*> aDoctypeName,
tainted_expat<const XML_Char*> aSysid,
tainted_expat<const XML_Char*> aPubid,
tainted_expat<int> aHasInternalSubset) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
const auto* doctypeName =
aDoctypeName.copy_and_verify_address(unverified_xml_string);
const auto* sysid = aSysid.copy_and_verify_address(unverified_xml_string);
const auto* pubid = aPubid.copy_and_verify_address(unverified_xml_string);
bool hasInternalSubset =
!!(aHasInternalSubset.copy_and_verify(safe_unverified<int>));
driver->HandleStartDoctypeDecl(doctypeName, sysid, pubid, hasInternalSubset);
}
static void Driver_HandleEndDoctypeDecl(void* aUserData) {
NS_ASSERTION(aUserData, "expat driver should exist");
if (aUserData) {
static_cast<nsExpatDriver*>(aUserData)->HandleEndDoctypeDecl();
}
static void Driver_HandleEndDoctypeDecl(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> /* aUserData */) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
driver->HandleEndDoctypeDecl();
}
static int Driver_HandleExternalEntityRef(void* aExternalEntityRefHandler,
const XML_Char* aOpenEntityNames,
const XML_Char* aBase,
const XML_Char* aSystemId,
const XML_Char* aPublicId) {
NS_ASSERTION(aExternalEntityRefHandler, "expat driver should exist");
if (!aExternalEntityRefHandler) {
return 1;
}
static tainted_expat<int> Driver_HandleExternalEntityRef(
rlbox_sandbox_expat& aSandbox, tainted_expat<XML_Parser> /* aParser */,
tainted_expat<const XML_Char*> aOpenEntityNames,
tainted_expat<const XML_Char*> aBase,
tainted_expat<const XML_Char*> aSystemId,
tainted_expat<const XML_Char*> aPublicId) {
nsExpatDriver* driver = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(driver);
nsExpatDriver* driver =
static_cast<nsExpatDriver*>(aExternalEntityRefHandler);
return driver->HandleExternalEntityRef(aOpenEntityNames, aBase, aSystemId,
aPublicId);
const auto* openEntityNames =
aOpenEntityNames.copy_and_verify_address(unverified_xml_string);
const auto* base = aBase.copy_and_verify_address(unverified_xml_string);
const auto* systemId =
aSystemId.copy_and_verify_address(unverified_xml_string);
const auto* publicId =
aPublicId.copy_and_verify_address(unverified_xml_string);
return driver->HandleExternalEntityRef(openEntityNames, base, systemId,
publicId);
}
/***************************** END CALL BACKS ********************************/
@ -260,28 +378,79 @@ nsExpatDriver::nsExpatDriver()
mCatalogData(nullptr),
mInnerWindowID(0) {}
nsExpatDriver::~nsExpatDriver() {
if (mExpatParser) {
XML_ParserFree(mExpatParser);
nsExpatDriver::~nsExpatDriver() { Destroy(); }
void nsExpatDriver::Destroy() {
if (mSandboxPoolData) {
SandboxData()->DetachDriver();
if (mExpatParser) {
RLBOX_EXPAT_MCALL(MOZ_XML_ParserFree);
}
}
mSandboxPoolData.reset();
mExpatParser = nullptr;
}
// The AllocAttrs class is used to speed up copying attributes from the
// sandboxed expat by fast allocating attributes on the stack and only falling
// back to malloc when we need to allocate lots of attributes.
class MOZ_STACK_CLASS AllocAttrs {
#define NUM_STACK_SLOTS 16
public:
const char16_t** Init(size_t size) {
if (size <= NUM_STACK_SLOTS) {
return mInlineArr;
}
mHeapPtr = mozilla::MakeUnique<const char16_t*[]>(size);
return mHeapPtr.get();
}
private:
const char16_t* mInlineArr[NUM_STACK_SLOTS];
mozilla::UniquePtr<const char16_t*[]> mHeapPtr;
#undef NUM_STACK_SLOTS
};
/* static */
void nsExpatDriver::HandleStartElement(void* aUserData, const char16_t* aName,
const char16_t** aAtts) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aUserData);
void nsExpatDriver::HandleStartElement(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> /* aUserData */,
tainted_expat<const char16_t*> aName,
tainted_expat<const char16_t**> aAttrs) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(self && self->mSink);
NS_ASSERTION(self->mSink, "content sink not found!");
const auto* name = aName.copy_and_verify_address(unverified_xml_string);
// Calculate the total number of elements in aAtts.
// Calculate the total number of elements in aAttrs.
// XML_GetSpecifiedAttributeCount will only give us the number of specified
// attrs (twice that number, actually), so we have to check for default attrs
// ourselves.
// attrs (twice that number, actually), so we have to check for default
// attrs ourselves.
int count = RLBOX_EXPAT_SAFE_CALL(MOZ_XML_GetSpecifiedAttributeCount,
safe_unverified<int>);
MOZ_RELEASE_ASSERT(count >= 0, "Unexpected attribute count");
uint32_t attrArrayLength;
for (attrArrayLength = XML_GetSpecifiedAttributeCount(self->mExpatParser);
aAtts[attrArrayLength]; attrArrayLength += 2) {
for (attrArrayLength = count;
(aAttrs[attrArrayLength] != nullptr)
.unverified_safe_because("Bad length is checked later");
attrArrayLength += 2) {
// Just looping till we find out what the length is
}
// A malicious length could result in an overflow when we allocate aAttrs
// and then access elements of the array.
MOZ_RELEASE_ASSERT(attrArrayLength < UINT32_MAX, "Overflow attempt");
// Copy tainted aAttrs from sandbox
AllocAttrs allocAttrs;
const char16_t** attrs = allocAttrs.Init(attrArrayLength + 1);
if (NS_WARN_IF(!aAttrs || !attrs)) {
self->MaybeStopParser(NS_ERROR_OUT_OF_MEMORY);
return;
}
for (uint32_t i = 0; i < attrArrayLength; i++) {
attrs[i] = aAttrs[i].copy_and_verify_address(unverified_xml_string);
}
attrs[attrArrayLength] = nullptr;
if (self->mSink) {
// We store the tagdepth in a PRUint16, so make sure the limit fits in a
@ -296,31 +465,41 @@ void nsExpatDriver::HandleStartElement(void* aUserData, const char16_t* aName,
}
nsresult rv = self->mSink->HandleStartElement(
aName, aAtts, attrArrayLength,
XML_GetCurrentLineNumber(self->mExpatParser),
XML_GetCurrentColumnNumber(self->mExpatParser));
name, attrs, attrArrayLength,
RLBOX_EXPAT_SAFE_CALL(MOZ_XML_GetCurrentLineNumber,
safe_unverified<XML_Size>),
RLBOX_EXPAT_SAFE_CALL(MOZ_XML_GetCurrentColumnNumber,
safe_unverified<XML_Size>));
self->MaybeStopParser(rv);
}
}
/* static */
void nsExpatDriver::HandleStartElementForSystemPrincipal(
void* aUserData, const char16_t* aName, const char16_t** aAtts) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aUserData);
if (!MOZ_XML_ProcessingEntityValue(self->mExpatParser)) {
HandleStartElement(aUserData, aName, aAtts);
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> aUserData,
tainted_expat<const char16_t*> aName,
tainted_expat<const char16_t**> aAttrs) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(self);
if (!RLBOX_EXPAT_SAFE_CALL(MOZ_XML_ProcessingEntityValue,
safe_unverified<XML_Bool>)) {
HandleStartElement(aSandbox, aUserData, aName, aAttrs);
} else {
nsCOMPtr<Document> doc =
do_QueryInterface(self->mOriginalSink->GetTarget());
// Adjust the column number so that it is one based rather than zero based.
uint32_t colNumber = XML_GetCurrentColumnNumber(self->mExpatParser) + 1;
uint32_t lineNumber = XML_GetCurrentLineNumber(self->mExpatParser);
// Adjust the column number so that it is one based rather than zero
// based.
uint32_t colNumber = RLBOX_EXPAT_SAFE_CALL(MOZ_XML_GetCurrentColumnNumber,
safe_unverified<XML_Size>) +
1;
uint32_t lineNumber = RLBOX_EXPAT_SAFE_CALL(MOZ_XML_GetCurrentLineNumber,
safe_unverified<XML_Size>);
int32_t nameSpaceID;
RefPtr<nsAtom> prefix, localName;
nsContentUtils::SplitExpatName(aName, getter_AddRefs(prefix),
const auto* name = aName.copy_and_verify_address(unverified_xml_string);
nsContentUtils::SplitExpatName(name, getter_AddRefs(prefix),
getter_AddRefs(localName), &nameSpaceID);
nsAutoString error;
@ -339,27 +518,33 @@ void nsExpatDriver::HandleStartElementForSystemPrincipal(
}
/* static */
void nsExpatDriver::HandleEndElement(void* aUserData, const char16_t* aName) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aUserData);
void nsExpatDriver::HandleEndElement(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> aUserData,
tainted_expat<const char16_t*> aName) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(self);
const auto* name = aName.copy_and_verify_address(unverified_xml_string);
NS_ASSERTION(self->mSink, "content sink not found!");
NS_ASSERTION(self->mInternalState != NS_ERROR_HTMLPARSER_BLOCK,
"Shouldn't block from HandleStartElement.");
if (self->mSink && self->mInternalState != NS_ERROR_HTMLPARSER_STOPPARSING) {
nsresult rv = self->mSink->HandleEndElement(aName);
nsresult rv = self->mSink->HandleEndElement(name);
--self->mTagDepth;
self->MaybeStopParser(rv);
}
}
/* static */
void nsExpatDriver::HandleEndElementForSystemPrincipal(void* aUserData,
const char16_t* aName) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aUserData);
if (!MOZ_XML_ProcessingEntityValue(self->mExpatParser)) {
HandleEndElement(aUserData, aName);
void nsExpatDriver::HandleEndElementForSystemPrincipal(
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> aUserData,
tainted_expat<const char16_t*> aName) {
nsExpatDriver* self = static_cast<nsExpatDriver*>(aSandbox.sandbox_storage);
MOZ_ASSERT(self);
if (!RLBOX_EXPAT_SAFE_CALL(MOZ_XML_ProcessingEntityValue,
safe_unverified<XML_Bool>)) {
HandleEndElement(aSandbox, aUserData, aName);
}
}
@ -533,21 +718,50 @@ nsresult nsExpatDriver::HandleEndDoctypeDecl() {
return NS_OK;
}
// Wrapper class for passing the sandbox data and parser as a closure to
// ExternalDTDStreamReaderFunc.
class RLBoxExpatClosure {
public:
RLBoxExpatClosure(RLBoxExpatSandboxData* aSbxData,
tainted_expat<XML_Parser> aExpatParser)
: mSbxData(aSbxData), mExpatParser(aExpatParser){};
inline rlbox_sandbox_expat* Sandbox() const { return mSbxData->Sandbox(); };
inline tainted_expat<XML_Parser> Parser() const { return mExpatParser; };
private:
RLBoxExpatSandboxData* mSbxData;
tainted_expat<XML_Parser> mExpatParser;
};
static nsresult ExternalDTDStreamReaderFunc(nsIUnicharInputStream* aIn,
void* aClosure,
const char16_t* aFromSegment,
uint32_t aToOffset, uint32_t aCount,
uint32_t* aWriteCount) {
// Pass the buffer to expat for parsing.
if (XML_Parse((XML_Parser)aClosure, (const char*)aFromSegment,
aCount * sizeof(char16_t), 0) == XML_STATUS_OK) {
*aWriteCount = aCount;
return NS_OK;
}
MOZ_ASSERT(aClosure && aFromSegment && aWriteCount);
*aWriteCount = 0;
// Get sandbox and parser
auto* closure = reinterpret_cast<RLBoxExpatClosure*>(aClosure);
MOZ_ASSERT(closure);
// Transfer segment into the sandbox
auto fromSegment =
TransferBuffer<char16_t>(closure->Sandbox(), aFromSegment, aCount);
NS_ENSURE_TRUE(*fromSegment, NS_ERROR_OUT_OF_MEMORY);
// Pass the buffer to expat for parsing.
if (closure->Sandbox()
->invoke_sandbox_function(
MOZ_XML_Parse, closure->Parser(),
rlbox::sandbox_reinterpret_cast<const char*>(*fromSegment),
aCount * sizeof(char16_t), 0)
.copy_and_verify(status_verifier) == XML_STATUS_OK) {
*aWriteCount = aCount;
return NS_OK;
}
return NS_ERROR_FAILURE;
}
@ -588,24 +802,33 @@ int nsExpatDriver::HandleExternalEntityRef(const char16_t* openEntityNames,
int result = 1;
if (uniIn) {
XML_Parser entParser =
XML_ExternalEntityParserCreate(mExpatParser, 0, kUTF16);
auto utf16 = TransferBuffer<char16_t>(
Sandbox(), kUTF16, nsCharTraits<char16_t>::length(kUTF16) + 1);
tainted_expat<XML_Parser> entParser;
entParser =
RLBOX_EXPAT_MCALL(MOZ_XML_ExternalEntityParserCreate, nullptr, *utf16);
if (entParser) {
XML_SetBase(entParser, absURL.get());
auto url = TransferBuffer<XML_Char>(Sandbox(), (XML_Char*)absURL.get(),
absURL.Length() + 1);
Sandbox()->invoke_sandbox_function(MOZ_XML_SetBase, entParser, *url);
mInExternalDTD = true;
uint32_t totalRead;
do {
rv = uniIn->ReadSegments(ExternalDTDStreamReaderFunc, entParser,
RLBoxExpatClosure closure(SandboxData(), entParser);
rv = uniIn->ReadSegments(ExternalDTDStreamReaderFunc, &closure,
uint32_t(-1), &totalRead);
} while (NS_SUCCEEDED(rv) && totalRead > 0);
result = XML_Parse(entParser, nullptr, 0, 1);
result =
Sandbox()
->invoke_sandbox_function(MOZ_XML_Parse, entParser, nullptr, 0, 1)
.copy_and_verify(status_verifier);
mInExternalDTD = false;
XML_ParserFree(entParser);
Sandbox()->invoke_sandbox_function(MOZ_XML_ParserFree, entParser);
}
}
@ -750,8 +973,7 @@ static nsresult AppendErrorPointer(const int32_t aColNumber,
}
nsresult nsExpatDriver::HandleError() {
int32_t code = XML_GetErrorCode(mExpatParser);
NS_ASSERTION(code > XML_ERROR_NONE, "unexpected XML error code");
int32_t code = RLBOX_EXPAT_SAFE_MCALL(MOZ_XML_GetErrorCode, error_verifier);
// Map Expat error code to an error string
// XXX Deal with error returns.
@ -777,7 +999,10 @@ nsresult nsExpatDriver::HandleError() {
* and we use 0xFFFF for the <separator>.
*
*/
const char16_t* mismatch = MOZ_XML_GetMismatchedTag(mExpatParser);
const char16_t* mismatch =
RLBOX_EXPAT_MCALL(MOZ_XML_GetMismatchedTag)
.copy_and_verify_address(unverified_xml_string);
const char16_t* uriEnd = nullptr;
const char16_t* nameEnd = nullptr;
const char16_t* pos;
@ -812,12 +1037,17 @@ nsresult nsExpatDriver::HandleError() {
}
// Adjust the column number so that it is one based rather than zero based.
uint32_t colNumber = XML_GetCurrentColumnNumber(mExpatParser) + 1;
uint32_t lineNumber = XML_GetCurrentLineNumber(mExpatParser);
uint32_t colNumber = RLBOX_EXPAT_SAFE_MCALL(MOZ_XML_GetCurrentColumnNumber,
safe_unverified<XML_Size>) +
1;
uint32_t lineNumber = RLBOX_EXPAT_SAFE_MCALL(MOZ_XML_GetCurrentLineNumber,
safe_unverified<XML_Size>);
nsAutoString errorText;
CreateErrorText(description.get(), XML_GetBase(mExpatParser), lineNumber,
colNumber, errorText, spoofEnglish);
const auto* aBase = RLBOX_EXPAT_MCALL(MOZ_XML_GetBase)
.copy_and_verify_address(unverified_xml_string);
CreateErrorText(description.get(), aBase, lineNumber, colNumber, errorText,
spoofEnglish);
nsAutoString sourceText(mLastLine);
AppendErrorPointer(colNumber, mLastLine.get(), sourceText);
@ -901,29 +1131,41 @@ void nsExpatDriver::ParseBuffer(const char16_t* aBuffer, uint32_t aLength,
"Useless call, we won't call Expat");
MOZ_ASSERT(!BlockedOrInterrupted() || !aBuffer,
"Non-null buffer when resuming");
MOZ_ASSERT(XML_GetCurrentByteIndex(mExpatParser) % sizeof(char16_t) == 0,
"Consumed part of a char16_t?");
MOZ_ASSERT(mExpatParser);
if (mExpatParser && (mInternalState == NS_OK || BlockedOrInterrupted())) {
int32_t parserBytesBefore = XML_GetCurrentByteIndex(mExpatParser);
NS_ASSERTION(parserBytesBefore >= 0, "Unexpected value");
auto parserBytesBefore_verifier = [&](auto parserBytesBefore) {
MOZ_RELEASE_ASSERT(parserBytesBefore >= 0, "Unexpected value");
MOZ_RELEASE_ASSERT(parserBytesBefore % sizeof(char16_t) == 0,
"Consumed part of a char16_t?");
return parserBytesBefore;
};
int32_t parserBytesBefore = RLBOX_EXPAT_SAFE_MCALL(
XML_GetCurrentByteIndex, parserBytesBefore_verifier);
if (mInternalState == NS_OK || BlockedOrInterrupted()) {
XML_Status status;
if (BlockedOrInterrupted()) {
mInternalState = NS_OK; // Resume in case we're blocked.
status = XML_ResumeParser(mExpatParser);
status = RLBOX_EXPAT_SAFE_MCALL(MOZ_XML_ResumeParser, status_verifier);
} else {
status = XML_Parse(mExpatParser, reinterpret_cast<const char*>(aBuffer),
aLength * sizeof(char16_t), aIsFinal);
auto buffer = TransferBuffer<char16_t>(Sandbox(), aBuffer, aLength);
status = RLBOX_EXPAT_SAFE_MCALL(
MOZ_XML_Parse, status_verifier,
rlbox::sandbox_reinterpret_cast<const char*>(*buffer),
aLength * sizeof(char16_t), aIsFinal);
}
int32_t parserBytesConsumed = XML_GetCurrentByteIndex(mExpatParser);
NS_ASSERTION(parserBytesConsumed >= 0, "Unexpected value");
NS_ASSERTION(parserBytesConsumed >= parserBytesBefore,
"How'd this happen?");
NS_ASSERTION(parserBytesConsumed % sizeof(char16_t) == 0,
"Consumed part of a char16_t?");
auto parserBytesConsumed_verifier = [&](auto parserBytesConsumed) {
MOZ_RELEASE_ASSERT(parserBytesConsumed >= 0, "Unexpected value");
MOZ_RELEASE_ASSERT(parserBytesConsumed >= parserBytesBefore,
"How'd this happen?");
MOZ_RELEASE_ASSERT(parserBytesConsumed % sizeof(char16_t) == 0,
"Consumed part of a char16_t?");
return parserBytesConsumed;
};
int32_t parserBytesConsumed = RLBOX_EXPAT_SAFE_MCALL(
XML_GetCurrentByteIndex, parserBytesConsumed_verifier);
// Consumed something.
*aConsumed = (parserBytesConsumed - parserBytesBefore) / sizeof(char16_t);
@ -1018,7 +1260,8 @@ nsExpatDriver::ConsumeToken(nsScanner& aScanner, bool& aFlushTokens) {
// the error occurred).
// The length of the last line that Expat has parsed.
XML_Size lastLineLength = XML_GetCurrentColumnNumber(mExpatParser);
XML_Size lastLineLength = RLBOX_EXPAT_SAFE_MCALL(
XML_GetCurrentColumnNumber, safe_unverified<XML_Size>);
if (lastLineLength <= consumed) {
// The length of the last line was less than what expat consumed, so
@ -1057,7 +1300,8 @@ nsExpatDriver::ConsumeToken(nsScanner& aScanner, bool& aFlushTokens) {
}
if (NS_FAILED(mInternalState)) {
if (XML_GetErrorCode(mExpatParser) != XML_ERROR_NONE) {
if (RLBOX_EXPAT_SAFE_MCALL(MOZ_XML_GetErrorCode, error_verifier) !=
XML_ERROR_NONE) {
NS_ASSERTION(mInternalState == NS_ERROR_HTMLPARSER_STOPPARSING,
"Unexpected error");
@ -1110,6 +1354,107 @@ nsExpatDriver::ConsumeToken(nsScanner& aScanner, bool& aFlushTokens) {
return NS_SUCCEEDED(mInternalState) ? NS_ERROR_HTMLPARSER_EOF : NS_OK;
}
mozilla::UniquePtr<mozilla::RLBoxSandboxDataBase>
RLBoxExpatSandboxPool::CreateSandboxData() {
// Create expat sandbox
auto sandbox = mozilla::MakeUnique<rlbox_sandbox_expat>();
#ifdef MOZ_WASM_SANDBOXING_EXPAT
bool create_ok = sandbox->create_sandbox(/* infallible = */ false);
#else
bool create_ok = sandbox->create_sandbox();
#endif
NS_ENSURE_TRUE(create_ok, nullptr);
mozilla::UniquePtr<RLBoxExpatSandboxData> sbxData =
mozilla::MakeUnique<RLBoxExpatSandboxData>();
// Register callbacks common to both system and non-system principals
sbxData->mHandleXMLDeclaration =
sandbox->register_callback(Driver_HandleXMLDeclaration);
sbxData->mHandleCharacterData =
sandbox->register_callback(Driver_HandleCharacterData);
sbxData->mHandleProcessingInstruction =
sandbox->register_callback(Driver_HandleProcessingInstruction);
sbxData->mHandleDefault = sandbox->register_callback(Driver_HandleDefault);
sbxData->mHandleExternalEntityRef =
sandbox->register_callback(Driver_HandleExternalEntityRef);
sbxData->mHandleComment = sandbox->register_callback(Driver_HandleComment);
sbxData->mHandleStartCdataSection =
sandbox->register_callback(Driver_HandleStartCdataSection);
sbxData->mHandleEndCdataSection =
sandbox->register_callback(Driver_HandleEndCdataSection);
sbxData->mHandleStartDoctypeDecl =
sandbox->register_callback(Driver_HandleStartDoctypeDecl);
sbxData->mHandleEndDoctypeDecl =
sandbox->register_callback(Driver_HandleEndDoctypeDecl);
sbxData->mSandbox = std::move(sandbox);
return sbxData;
}
mozilla::StaticRefPtr<RLBoxExpatSandboxPool> RLBoxExpatSandboxPool::sSingleton;
void RLBoxExpatSandboxPool::Initialize(size_t aDelaySeconds) {
mozilla::AssertIsOnMainThread();
RLBoxExpatSandboxPool::sSingleton = new RLBoxExpatSandboxPool(aDelaySeconds);
ClearOnShutdown(&RLBoxExpatSandboxPool::sSingleton);
}
void RLBoxExpatSandboxData::AttachDriver(bool aIsSystemPrincipal,
void* aDriver) {
MOZ_ASSERT(!mSandbox->sandbox_storage);
MOZ_ASSERT(mHandleStartElement.is_unregistered());
MOZ_ASSERT(mHandleEndElement.is_unregistered());
if (aIsSystemPrincipal) {
mHandleStartElement = mSandbox->register_callback(
nsExpatDriver::HandleStartElementForSystemPrincipal);
mHandleEndElement = mSandbox->register_callback(
nsExpatDriver::HandleEndElementForSystemPrincipal);
} else {
mHandleStartElement =
mSandbox->register_callback(nsExpatDriver::HandleStartElement);
mHandleEndElement =
mSandbox->register_callback(nsExpatDriver::HandleEndElement);
}
mSandbox->sandbox_storage = aDriver;
}
void RLBoxExpatSandboxData::DetachDriver() {
mSandbox->sandbox_storage = nullptr;
mHandleStartElement.unregister();
mHandleEndElement.unregister();
}
RLBoxExpatSandboxData::~RLBoxExpatSandboxData() {
MOZ_ASSERT(mSandbox);
// DetachDriver should always be called before a sandbox goes back into the
// pool, and thus before it's freed.
MOZ_ASSERT(!mSandbox->sandbox_storage);
MOZ_ASSERT(mHandleStartElement.is_unregistered());
MOZ_ASSERT(mHandleEndElement.is_unregistered());
// Unregister callbacks
mHandleXMLDeclaration.unregister();
mHandleCharacterData.unregister();
mHandleProcessingInstruction.unregister();
mHandleDefault.unregister();
mHandleExternalEntityRef.unregister();
mHandleComment.unregister();
mHandleStartCdataSection.unregister();
mHandleEndCdataSection.unregister();
mHandleStartDoctypeDecl.unregister();
mHandleEndDoctypeDecl.unregister();
// Destroy sandbox
mSandbox->destroy_sandbox();
MOZ_COUNT_DTOR(RLBoxExpatSandboxData);
}
NS_IMETHODIMP
nsExpatDriver::WillBuildModel(const CParserContext& aParserContext,
nsITokenizer* aTokenizer, nsIContentSink* aSink) {
@ -1123,23 +1468,9 @@ nsExpatDriver::WillBuildModel(const CParserContext& aParserContext,
mOriginalSink = aSink;
static const XML_Memory_Handling_Suite memsuite = {malloc, realloc, free};
static const char16_t kExpatSeparator[] = {kExpatSeparatorChar, '\0'};
mExpatParser = XML_ParserCreate_MM(kUTF16, &memsuite, kExpatSeparator);
NS_ENSURE_TRUE(mExpatParser, NS_ERROR_FAILURE);
XML_SetReturnNSTriplet(mExpatParser, XML_TRUE);
#ifdef XML_DTD
XML_SetParamEntityParsing(mExpatParser, XML_PARAM_ENTITY_PARSING_ALWAYS);
#endif
mURISpec = aParserContext.mScanner->GetFilename();
XML_SetBase(mExpatParser, mURISpec.get());
// Get the doc if any
nsCOMPtr<Document> doc = do_QueryInterface(mOriginalSink->GetTarget());
if (doc) {
nsCOMPtr<nsPIDOMWindowOuter> win = doc->GetWindow();
@ -1159,33 +1490,66 @@ nsExpatDriver::WillBuildModel(const CParserContext& aParserContext,
}
}
// Create sandbox
MOZ_ASSERT(!mSandboxPoolData);
mSandboxPoolData = RLBoxExpatSandboxPool::sSingleton->PopOrCreate();
NS_ENSURE_TRUE(mSandboxPoolData, NS_ERROR_OUT_OF_MEMORY);
MOZ_ASSERT(SandboxData());
SandboxData()->AttachDriver(doc && doc->NodePrincipal()->IsSystemPrincipal(),
static_cast<void*>(this));
// Create expat parser.
// We need to copy the encoding and namespace separator into the sandbox.
// For the noop sandbox we pass in the memsuite; for the Wasm sandbox, we
// pass in nullptr to let expat use the standard library memory suite.
auto expatSeparator = TransferBuffer<char16_t>(
Sandbox(), kExpatSeparator,
nsCharTraits<char16_t>::length(kExpatSeparator) + 1);
auto utf16 = TransferBuffer<char16_t>(
Sandbox(), kUTF16, nsCharTraits<char16_t>::length(kUTF16) + 1);
mExpatParser = Sandbox()->invoke_sandbox_function(
MOZ_XML_ParserCreate_MM, *utf16, nullptr, *expatSeparator);
NS_ENSURE_TRUE(mExpatParser, NS_ERROR_FAILURE);
RLBOX_EXPAT_MCALL(MOZ_XML_SetReturnNSTriplet, XML_TRUE);
#ifdef XML_DTD
RLBOX_EXPAT_MCALL(MOZ_XML_SetParamEntityParsing,
XML_PARAM_ENTITY_PARSING_ALWAYS);
#endif
mURISpec = aParserContext.mScanner->GetFilename();
const XML_Char* uriStr = mURISpec.get();
auto uri = TransferBuffer<XML_Char>(Sandbox(), uriStr, mURISpec.Length() + 1);
RLBOX_EXPAT_MCALL(MOZ_XML_SetBase, *uri);
// Set up the callbacks
XML_SetXmlDeclHandler(mExpatParser, Driver_HandleXMLDeclaration);
if (doc && doc->NodePrincipal()->IsSystemPrincipal()) {
XML_SetElementHandler(mExpatParser, HandleStartElementForSystemPrincipal,
HandleEndElementForSystemPrincipal);
} else {
XML_SetElementHandler(mExpatParser, HandleStartElement, HandleEndElement);
}
XML_SetCharacterDataHandler(mExpatParser, Driver_HandleCharacterData);
XML_SetProcessingInstructionHandler(mExpatParser,
Driver_HandleProcessingInstruction);
XML_SetDefaultHandlerExpand(mExpatParser, Driver_HandleDefault);
XML_SetExternalEntityRefHandler(
mExpatParser,
(XML_ExternalEntityRefHandler)Driver_HandleExternalEntityRef);
XML_SetExternalEntityRefHandlerArg(mExpatParser, this);
XML_SetCommentHandler(mExpatParser, Driver_HandleComment);
XML_SetCdataSectionHandler(mExpatParser, Driver_HandleStartCdataSection,
Driver_HandleEndCdataSection);
RLBOX_EXPAT_MCALL(MOZ_XML_SetXmlDeclHandler,
SandboxData()->mHandleXMLDeclaration);
RLBOX_EXPAT_MCALL(MOZ_XML_SetElementHandler,
SandboxData()->mHandleStartElement,
SandboxData()->mHandleEndElement);
RLBOX_EXPAT_MCALL(MOZ_XML_SetCharacterDataHandler,
SandboxData()->mHandleCharacterData);
RLBOX_EXPAT_MCALL(MOZ_XML_SetProcessingInstructionHandler,
SandboxData()->mHandleProcessingInstruction);
RLBOX_EXPAT_MCALL(MOZ_XML_SetDefaultHandlerExpand,
SandboxData()->mHandleDefault);
RLBOX_EXPAT_MCALL(MOZ_XML_SetExternalEntityRefHandler,
SandboxData()->mHandleExternalEntityRef);
RLBOX_EXPAT_MCALL(MOZ_XML_SetCommentHandler, SandboxData()->mHandleComment);
RLBOX_EXPAT_MCALL(MOZ_XML_SetCdataSectionHandler,
SandboxData()->mHandleStartCdataSection,
SandboxData()->mHandleEndCdataSection);
XML_SetParamEntityParsing(mExpatParser,
XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE);
XML_SetDoctypeDeclHandler(mExpatParser, Driver_HandleStartDoctypeDecl,
Driver_HandleEndDoctypeDecl);
// Set up the user data.
XML_SetUserData(mExpatParser, this);
RLBOX_EXPAT_MCALL(MOZ_XML_SetParamEntityParsing,
XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE);
RLBOX_EXPAT_MCALL(MOZ_XML_SetDoctypeDeclHandler,
SandboxData()->mHandleStartDoctypeDecl,
SandboxData()->mHandleEndDoctypeDecl);
return mInternalState;
}
@ -1197,6 +1561,10 @@ nsExpatDriver::BuildModel(nsITokenizer* aTokenizer, nsIContentSink* aSink) {
NS_IMETHODIMP
nsExpatDriver::DidBuildModel(nsresult anErrorCode) {
// Because nsExpatDriver is cycle-collected, it gets destroyed
// asynchronously. Eagerly release the sandbox back into the pool so that it
// can be reused immediately.
Destroy();
mOriginalSink = nullptr;
mSink = nullptr;
return NS_OK;
@ -1212,7 +1580,7 @@ NS_IMETHODIMP_(void)
nsExpatDriver::Terminate() {
// XXX - not sure what happens to the unparsed data.
if (mExpatParser) {
XML_StopParser(mExpatParser, XML_FALSE);
RLBOX_EXPAT_MCALL(MOZ_XML_StopParser, XML_FALSE);
}
mInternalState = NS_ERROR_HTMLPARSER_STOPPARSING;
}
@ -1252,10 +1620,19 @@ void nsExpatDriver::MaybeStopParser(nsresult aState) {
// with false as the last argument). If the parser should be blocked or
// interrupted we need to pause Expat (by calling XML_StopParser with
// true as the last argument).
XML_StopParser(mExpatParser, BlockedOrInterrupted());
RLBOX_EXPAT_MCALL(MOZ_XML_StopParser, BlockedOrInterrupted());
} else if (NS_SUCCEEDED(mInternalState)) {
// Only clobber mInternalState with the success code if we didn't block or
// interrupt before.
mInternalState = aState;
}
}
inline RLBoxExpatSandboxData* nsExpatDriver::SandboxData() const {
return reinterpret_cast<RLBoxExpatSandboxData*>(
mSandboxPoolData->SandboxData());
}
inline rlbox_sandbox_expat* nsExpatDriver::Sandbox() const {
return SandboxData()->Sandbox();
}

72
parser/htmlparser/nsExpatDriver.h
View File

@ -16,8 +16,13 @@
#include "nsIParser.h"
#include "nsCycleCollectionParticipant.h"
#include "rlbox_expat.h"
#include "nsRLBoxExpatDriver.h"
#include "mozilla/UniquePtr.h"
class nsIExpatSink;
struct nsCatalogData;
class RLBoxExpatSandboxData;
class nsExpatDriver : public nsIDTD, public nsITokenizer {
virtual ~nsExpatDriver();
@ -33,14 +38,20 @@ class nsExpatDriver : public nsIDTD, public nsITokenizer {
int HandleExternalEntityRef(const char16_t* aOpenEntityNames,
const char16_t* aBase, const char16_t* aSystemId,
const char16_t* aPublicId);
static void HandleStartElement(void* aUserData, const char16_t* aName,
const char16_t** aAtts);
static void HandleStartElementForSystemPrincipal(void* aUserData,
const char16_t* aName,
const char16_t** aAtts);
static void HandleEndElement(void* aUserData, const char16_t* aName);
static void HandleEndElementForSystemPrincipal(void* aUserData,
const char16_t* aName);
static void HandleStartElement(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> aUserData,
tainted_expat<const char16_t*> aName,
tainted_expat<const char16_t**> aAtts);
static void HandleStartElementForSystemPrincipal(
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> aUserData,
tainted_expat<const char16_t*> aName,
tainted_expat<const char16_t**> aAtts);
static void HandleEndElement(rlbox_sandbox_expat& aSandbox,
tainted_expat<void*> aUserData,
tainted_expat<const char16_t*> aName);
static void HandleEndElementForSystemPrincipal(
rlbox_sandbox_expat& aSandbox, tainted_expat<void*> aUserData,
tainted_expat<const char16_t*> aName);
nsresult HandleCharacterData(const char16_t* aCData, const uint32_t aLength);
nsresult HandleComment(const char16_t* aName);
nsresult HandleProcessingInstruction(const char16_t* aTarget,
@ -91,7 +102,15 @@ class nsExpatDriver : public nsIDTD, public nsITokenizer {
mInternalState == NS_ERROR_HTMLPARSER_INTERRUPTED;
}
XML_Parser mExpatParser;
RLBoxExpatSandboxData* SandboxData() const;
rlbox_sandbox_expat* Sandbox() const;
// Destroy expat parser and return sandbox to pool
void Destroy();
mozilla::UniquePtr<mozilla::RLBoxSandboxPoolData> mSandboxPoolData;
tainted_expat<XML_Parser> mExpatParser;
nsString mLastLine;
nsString mCDataText;
// Various parts of a doctype
@ -128,4 +147,39 @@ class nsExpatDriver : public nsIDTD, public nsITokenizer {
uint64_t mInnerWindowID;
};
class RLBoxExpatSandboxData : public mozilla::RLBoxSandboxDataBase {
friend class RLBoxExpatSandboxPool;
friend class nsExpatDriver;
public:
MOZ_COUNTED_DEFAULT_CTOR(RLBoxExpatSandboxData);
~RLBoxExpatSandboxData();
rlbox_sandbox_expat* Sandbox() const { return mSandbox.get(); }
// After getting a sandbox from the pool we need to register the
// Handle{Start,End}Element callbacks and associate the driver with the
// sandbox.
void AttachDriver(bool IsSystemPrincipal, void* aDriver);
void DetachDriver();
private:
mozilla::UniquePtr<rlbox_sandbox_expat> mSandbox;
// Common expat callbacks that persist across calls to {Attach,Detach}Driver,
// and consequently across sandbox reuses.
sandbox_callback_expat<XML_XmlDeclHandler> mHandleXMLDeclaration;
sandbox_callback_expat<XML_CharacterDataHandler> mHandleCharacterData;
sandbox_callback_expat<XML_ProcessingInstructionHandler>
mHandleProcessingInstruction;
sandbox_callback_expat<XML_DefaultHandler> mHandleDefault;
sandbox_callback_expat<XML_ExternalEntityRefHandler> mHandleExternalEntityRef;
sandbox_callback_expat<XML_CommentHandler> mHandleComment;
sandbox_callback_expat<XML_StartCdataSectionHandler> mHandleStartCdataSection;
sandbox_callback_expat<XML_EndCdataSectionHandler> mHandleEndCdataSection;
sandbox_callback_expat<XML_StartDoctypeDeclHandler> mHandleStartDoctypeDecl;
sandbox_callback_expat<XML_EndDoctypeDeclHandler> mHandleEndDoctypeDecl;
// Expat callbacks specific to each driver, and thus (re)set across sandbox
// reuses.
sandbox_callback_expat<XML_StartElementHandler> mHandleStartElement;
sandbox_callback_expat<XML_EndElementHandler> mHandleEndElement;
};
#endif

27
parser/htmlparser/nsRLBoxExpatDriver.h Normal file
View File

@ -0,0 +1,27 @@
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 http://mozilla.org/MPL/2.0/. */
#ifndef NS_RLBOX_EXPAT_DRIVER__
#define NS_RLBOX_EXPAT_DRIVER__
#include "mozilla/RLBoxSandboxPool.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/UniquePtr.h"
class RLBoxExpatSandboxPool : public mozilla::RLBoxSandboxPool {
public:
explicit RLBoxExpatSandboxPool(size_t aDelaySeconds)
: RLBoxSandboxPool(aDelaySeconds) {}
static mozilla::StaticRefPtr<RLBoxExpatSandboxPool> sSingleton;
static void Initialize(size_t aDelaySeconds = 10);
protected:
mozilla::UniquePtr<mozilla::RLBoxSandboxDataBase> CreateSandboxData()
override;
~RLBoxExpatSandboxPool() = default;
};
#endif

2
security/rlbox/include/RLBoxSandboxPool.h
View File

@ -83,7 +83,7 @@ class RLBoxSandboxPoolData {
MOZ_COUNT_CTOR(RLBoxSandboxPoolData);
}
const RLBoxSandboxDataBase* SandboxData() const { return mSbxData.get(); };
RLBoxSandboxDataBase* SandboxData() const { return mSbxData.get(); };
~RLBoxSandboxPoolData() {
mPool->Push(std::move(mSbxData));

8
security/rlbox/moz.build
View File

@ -45,6 +45,7 @@ AllowCompilerWarnings()
WASM_DEFINES["MOZILLA_CLIENT"] = True
WASM_DEFINES["_WASI_EMULATED_PROCESS_CLOCKS"] = True
WASM_DEFINES["MOZ_IN_WASM_SANDBOX"] = True
SANDBOXED_WASM_LIBRARY_NAME = "rlbox.wasm"
@ -72,3 +73,10 @@ if CONFIG["MOZ_WASM_SANDBOXING_OGG"]:
include("/media/libogg/sources.mozbuild")
WASM_SOURCES += ["/media/libogg/" + s for s in ogg_sources]
LOCAL_INCLUDES += ["/media/libogg"]
if CONFIG["MOZ_WASM_SANDBOXING_EXPAT"]:
include("/parser/expat/lib/sources.mozbuild")
WASM_SOURCES += ["/parser/expat/lib/" + s for s in expat_sources]
for k, v in expat_defines:
WASM_DEFINES[k] = v
LOCAL_INCLUDES += ["/parser/expat/lib/"]

11
security/rlbox/src/RLBoxSandboxPool.cpp
View File

@ -5,6 +5,7 @@
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsThreadUtils.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/RLBoxSandboxPool.h"
@ -15,6 +16,16 @@ NS_IMPL_ISUPPORTS(RLBoxSandboxPool, nsITimerCallback, nsINamed)
void RLBoxSandboxPool::StartTimer() {
mMutex.AssertCurrentThreadOwns();
MOZ_ASSERT(!mTimer, "timer already initialized");
if (NS_IsMainThread() &&
PastShutdownPhase(ShutdownPhase::AppShutdownConfirmed)) {
// If we're shutting down, setting the time might fail, and we don't need it
// (since all the memory will be cleaned up soon anyway). Note that
// PastShutdownPhase() can only be called on the main thread, but that's
// fine, because other threads will have joined already by the point timers
// start failing to register.
mPool.Clear();
return;
}
DebugOnly<nsresult> rv = NS_NewTimerWithCallback(
getter_AddRefs(mTimer), this, mDelaySeconds * 1000,
nsITimer::TYPE_ONE_SHOT, GetMainThreadEventTarget());