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Fix AMF0 value readers that leave part of a value unread #3674

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Merged
wasphin merged 1 commit into from
Oct 27, 2026
+99 −53
Merged

Fix AMF0 value readers that leave part of a value unread #3674

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39 changes: 25 additions & 14 deletions src/brpc/amf.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -462,7 +462,7 @@ static bool ReadAMFObjectField(AMFInputStream* stream,
LOG(ERROR) << "stream is not long enough";
return false;
}
switch ((AMFMarker)marker) {
switch (marker) {
case AMF_MARKER_NUMBER: {
uint64_t val = 0;
if (stream->cut_u64(&val) != 8u) {
Expand Down Expand Up @@ -511,20 +511,20 @@ static bool ReadAMFObjectField(AMFInputStream* stream,
std::string class_name;
if (!ReadAMFShortStringBody(&class_name, stream)) {
LOG(ERROR) << "Fail to read class_name";
return false;
}
}
// fall through
case AMF_MARKER_OBJECT: {
if (field) {
if (field->cpp_type() != google::protobuf::FieldDescriptor::CPPTYPE_MESSAGE) {
LOG(WARNING) << "Can't set object to " << field->full_name();
} else {
google::protobuf::Message* m = reflection->MutableMessage(message, field);
if (!ReadAMFObjectBody(m, stream, depth + 1)) {
return false;
}
if (field && field->cpp_type() == google::protobuf::FieldDescriptor::CPPTYPE_MESSAGE) {
google::protobuf::Message* m = reflection->MutableMessage(message, field);
if (!ReadAMFObjectBody(m, stream, depth + 1)) {
return false;
}
} else {
if (field) {
LOG(WARNING) << "Can't set object to " << field->full_name();
}
if (!SkipAMFObjectBody(stream, depth + 1)) {
return false;
}
Expand Down Expand Up @@ -563,6 +563,9 @@ static bool ReadAMFObjectField(AMFInputStream* stream,
}
}
} break;
default:
LOG(ERROR) << "Unknown marker=" << (int)marker;
return false;
} // switch
return true;
}
Expand All @@ -583,7 +586,7 @@ static bool ReadAMFObjectBody(google::protobuf::Message* message,
return false;
}
if ((AMFMarker)marker != AMF_MARKER_OBJECT_END) {
LOG(ERROR) << "marker=" << marker
LOG(ERROR) << "marker=" << (int)marker
<< " after empty name is not object end";
return false;
}
Expand Down Expand Up @@ -612,7 +615,7 @@ static bool SkipAMFObjectBody(AMFInputStream* stream, int depth) {
return false;
}
if ((AMFMarker)marker != AMF_MARKER_OBJECT_END) {
LOG(ERROR) << "marker=" << marker
LOG(ERROR) << "marker=" << (int)marker
<< " after empty name is not object end";
return false;
}
Expand Down Expand Up @@ -701,7 +704,7 @@ static bool ReadAMFObjectField(AMFInputStream* stream,
LOG(ERROR) << "stream is not long enough";
return false;
}
switch ((AMFMarker)marker) {
switch (marker) {
case AMF_MARKER_NUMBER: {
uint64_t val = 0;
if (stream->cut_u64(&val) != 8u) {
Expand Down Expand Up @@ -730,6 +733,7 @@ static bool ReadAMFObjectField(AMFInputStream* stream,
std::string class_name;
if (!ReadAMFShortStringBody(&class_name, stream)) {
LOG(ERROR) << "Fail to read class_name";
return false;
}
}
// fall through
Expand Down Expand Up @@ -776,6 +780,9 @@ static bool ReadAMFObjectField(AMFInputStream* stream,
}
obj->SetString(name, val);
} break;
default:
LOG(ERROR) << "Unknown marker=" << (int)marker;
return false;
} // switch
return true;
}
Expand All @@ -793,7 +800,7 @@ static bool ReadAMFObjectBody(AMFObject* obj, AMFInputStream* stream, int depth)
return false;
}
if ((AMFMarker)marker != AMF_MARKER_OBJECT_END) {
LOG(ERROR) << "marker=" << marker
LOG(ERROR) << "marker=" << (int)marker
<< " after empty name is not object end";
return false;
}
Expand Down Expand Up @@ -862,7 +869,7 @@ static bool ReadAMFArrayItem(AMFInputStream* stream, AMFArray* arr, int depth) {
LOG(ERROR) << "stream is not long enough";
return false;
}
switch ((AMFMarker)marker) {
switch (marker) {
case AMF_MARKER_NUMBER: {
uint64_t val = 0;
if (stream->cut_u64(&val) != 8u) {
Expand Down Expand Up @@ -891,6 +898,7 @@ static bool ReadAMFArrayItem(AMFInputStream* stream, AMFArray* arr, int depth) {
std::string class_name;
if (!ReadAMFShortStringBody(&class_name, stream)) {
LOG(ERROR) << "Fail to read class_name";
return false;
}
}
// fall through
Expand Down Expand Up @@ -937,6 +945,9 @@ static bool ReadAMFArrayItem(AMFInputStream* stream, AMFArray* arr, int depth) {
}
arr->AddString(val);
} break;
default:
LOG(ERROR) << "Unknown marker=" << (int)marker;
return false;
} // switch
return true;
}
Expand Down
113 changes: 74 additions & 39 deletions test/brpc_rtmp_unittest.cpp
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -901,47 +901,82 @@ TEST(RtmpTest, amf_rejects_oversized_strict_array_count) {
EXPECT_EQ(0u, arr.size());
}

TEST(RtmpTest, amf_rejects_stray_object_end_marker) {
// A stray object-end marker (0x09) in a value position used to hit
// CHECK(false): the process aborted with -crash_on_fatal_log, and the
// object/array readers then continued as if the input were valid.
{
// As the value of a field in a generic object.
std::string req_buf;
AppendAMFObjectHeader(&req_buf);
AppendAMFShortStringBody(&req_buf, "a");
req_buf.push_back((char)brpc::AMF_MARKER_OBJECT_END);
AppendAMFObjectEnd(&req_buf);

google::protobuf::io::ArrayInputStream zc_stream(req_buf.data(), req_buf.size());
brpc::AMFInputStream istream(&zc_stream);
brpc::AMFObject obj;
EXPECT_FALSE(brpc::ReadAMFObject(&obj, &istream));
TEST(RtmpTest, amf_rejects_invalid_value) {
// A value position must reject a stray object-end marker (0x09), any
// marker that AMF0 does not define (0x12 and up), and a typed object
// whose class name is longer than the limit.
ScopedAMFLimit scoped_limit(&brpc::FLAGS_amf_max_string_size, 4);
std::string typed_object(1, (char)brpc::AMF_MARKER_TYPED_OBJECT);
AppendAMFShortStringBody(&typed_object, "hello");
AppendAMFObjectEnd(&typed_object);
const std::string values[] = {
std::string(1, (char)brpc::AMF_MARKER_OBJECT_END),
std::string(1, (char)0x12),
std::string(1, (char)0xff),
typed_object,
};
for (size_t i = 0; i < arraysize(values); ++i) {
{
// As the value of a field in a generic object.
std::string req_buf;
AppendAMFObjectHeader(&req_buf);
AppendAMFShortStringBody(&req_buf, "a");
req_buf.append(values[i]);
AppendAMFObjectEnd(&req_buf);

google::protobuf::io::ArrayInputStream zc_stream(req_buf.data(), req_buf.size());
brpc::AMFInputStream istream(&zc_stream);
brpc::AMFObject obj;
EXPECT_FALSE(brpc::ReadAMFObject(&obj, &istream)) << "i=" << i;
}
{
// As an item of a strict array.
std::string req_buf;
AppendAMFStrictArrayHeader(&req_buf, 1);
req_buf.append(values[i]);

google::protobuf::io::ArrayInputStream zc_stream(req_buf.data(), req_buf.size());
brpc::AMFInputStream istream(&zc_stream);
brpc::AMFArray arr;
EXPECT_FALSE(brpc::ReadAMFArray(&arr, &istream)) << "i=" << i;
}
{
// As the value of a field mapped to a protobuf message.
std::string req_buf;
AppendAMFObjectHeader(&req_buf);
AppendAMFShortStringBody(&req_buf, "code");
req_buf.append(values[i]);
AppendAMFObjectEnd(&req_buf);

google::protobuf::io::ArrayInputStream zc_stream(req_buf.data(), req_buf.size());
brpc::AMFInputStream istream(&zc_stream);
brpc::RtmpInfo info;
EXPECT_FALSE(brpc::ReadAMFObject(&info, &istream)) << "i=" << i;
}
}
{
// As an item of a strict array.
std::string req_buf;
AppendAMFStrictArrayHeader(&req_buf, 1);
req_buf.push_back((char)brpc::AMF_MARKER_OBJECT_END);
}

google::protobuf::io::ArrayInputStream zc_stream(req_buf.data(), req_buf.size());
brpc::AMFInputStream istream(&zc_stream);
brpc::AMFArray arr;
EXPECT_FALSE(brpc::ReadAMFArray(&arr, &istream));
}
{
// As the value of a field mapped to a protobuf message.
std::string req_buf;
AppendAMFObjectHeader(&req_buf);
AppendAMFShortStringBody(&req_buf, "code");
req_buf.push_back((char)brpc::AMF_MARKER_OBJECT_END);
AppendAMFObjectEnd(&req_buf);

google::protobuf::io::ArrayInputStream zc_stream(req_buf.data(), req_buf.size());
brpc::AMFInputStream istream(&zc_stream);
brpc::RtmpInfo info;
EXPECT_FALSE(brpc::ReadAMFObject(&info, &istream));
}
TEST(RtmpTest, amf_skips_object_value_of_non_message_field) {
// {code: {level: "inner"}, description: "outer"}: code is a string.
std::string req_buf;
AppendAMFObjectHeader(&req_buf);
AppendAMFShortStringBody(&req_buf, "code");
AppendAMFObjectHeader(&req_buf);
AppendAMFShortStringBody(&req_buf, "level");
req_buf.push_back((char)brpc::AMF_MARKER_STRING);
AppendAMFShortStringBody(&req_buf, "inner");
AppendAMFObjectEnd(&req_buf);
AppendAMFShortStringBody(&req_buf, "description");
req_buf.push_back((char)brpc::AMF_MARKER_STRING);
AppendAMFShortStringBody(&req_buf, "outer");
AppendAMFObjectEnd(&req_buf);

google::protobuf::io::ArrayInputStream zc_stream(req_buf.data(), req_buf.size());
brpc::AMFInputStream istream(&zc_stream);
brpc::RtmpInfo info;
ASSERT_TRUE(brpc::ReadAMFObject(&info, &istream));
EXPECT_FALSE(info.has_level());
EXPECT_EQ("outer", info.description());
}

TEST(RtmpTest, amf_rejects_deep_nested_arrays) {
Expand Down
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