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author | sfan5 <sfan5@live.de> | 2021-08-19 20:14:22 +0200 |
---|---|---|
committer | GitHub <noreply@github.com> | 2021-08-19 20:14:22 +0200 |
commit | e7b05beb7d90b4ea53ef13da86ff8b8ccde1193b (patch) | |
tree | b87dfaf74cc8443298ad0e00a0381a88ce7c5ade | |
parent | 1320c51d8e15409544cba970a97b167a37513bae (diff) | |
download | minetest-e7b05beb7d90b4ea53ef13da86ff8b8ccde1193b.tar.gz minetest-e7b05beb7d90b4ea53ef13da86ff8b8ccde1193b.tar.bz2 minetest-e7b05beb7d90b4ea53ef13da86ff8b8ccde1193b.zip |
Validate staticdata and object property length limits (#11511)
Some games provide users with enough freedom to create items
with metadata longer than 64KB, preventing this from causing
issues is on them but we'll still do the minimum not to abort
the server if this happens.
-rw-r--r-- | src/object_properties.cpp | 34 | ||||
-rw-r--r-- | src/object_properties.h | 2 | ||||
-rw-r--r-- | src/script/lua_api/l_object.cpp | 2 | ||||
-rw-r--r-- | src/staticobject.cpp | 24 |
4 files changed, 61 insertions, 1 deletions
diff --git a/src/object_properties.cpp b/src/object_properties.cpp index 2eebc27d6..db06f8930 100644 --- a/src/object_properties.cpp +++ b/src/object_properties.cpp @@ -83,6 +83,39 @@ std::string ObjectProperties::dump() return os.str(); } +bool ObjectProperties::validate() +{ + const char *func = "ObjectProperties::validate(): "; + bool ret = true; + + // cf. where serializeString16 is used below + for (u32 i = 0; i < textures.size(); i++) { + if (textures[i].size() > U16_MAX) { + warningstream << func << "texture " << (i+1) << " has excessive length, " + "clearing it." << std::endl; + textures[i].clear(); + ret = false; + } + } + if (nametag.length() > U16_MAX) { + warningstream << func << "nametag has excessive length, clearing it." << std::endl; + nametag.clear(); + ret = false; + } + if (infotext.length() > U16_MAX) { + warningstream << func << "infotext has excessive length, clearing it." << std::endl; + infotext.clear(); + ret = false; + } + if (wield_item.length() > U16_MAX) { + warningstream << func << "wield_item has excessive length, clearing it." << std::endl; + wield_item.clear(); + ret = false; + } + + return ret; +} + void ObjectProperties::serialize(std::ostream &os) const { writeU8(os, 4); // PROTOCOL_VERSION >= 37 @@ -105,7 +138,6 @@ void ObjectProperties::serialize(std::ostream &os) const writeU8(os, is_visible); writeU8(os, makes_footstep_sound); writeF32(os, automatic_rotate); - // Added in protocol version 14 os << serializeString16(mesh); writeU16(os, colors.size()); for (video::SColor color : colors) { diff --git a/src/object_properties.h b/src/object_properties.h index db28eebfd..79866a22c 100644 --- a/src/object_properties.h +++ b/src/object_properties.h @@ -68,6 +68,8 @@ struct ObjectProperties ObjectProperties(); std::string dump(); + // check limits of some important properties (strings) that'd cause exceptions later on + bool validate(); void serialize(std::ostream &os) const; void deSerialize(std::istream &is); }; diff --git a/src/script/lua_api/l_object.cpp b/src/script/lua_api/l_object.cpp index 8e308cd9e..c404cb63c 100644 --- a/src/script/lua_api/l_object.cpp +++ b/src/script/lua_api/l_object.cpp @@ -685,6 +685,7 @@ int ObjectRef::l_set_properties(lua_State *L) return 0; read_object_properties(L, 2, sao, prop, getServer(L)->idef()); + prop->validate(); sao->notifyObjectPropertiesModified(); return 0; } @@ -752,6 +753,7 @@ int ObjectRef::l_set_nametag_attributes(lua_State *L) std::string nametag = getstringfield_default(L, 2, "text", ""); prop->nametag = nametag; + prop->validate(); sao->notifyObjectPropertiesModified(); lua_pushboolean(L, true); return 1; diff --git a/src/staticobject.cpp b/src/staticobject.cpp index 86e455b9f..1160ec68f 100644 --- a/src/staticobject.cpp +++ b/src/staticobject.cpp @@ -37,6 +37,7 @@ void StaticObject::serialize(std::ostream &os) // data os<<serializeString16(data); } + void StaticObject::deSerialize(std::istream &is, u8 version) { // type @@ -49,6 +50,29 @@ void StaticObject::deSerialize(std::istream &is, u8 version) void StaticObjectList::serialize(std::ostream &os) { + // Check for problems first + auto problematic = [] (StaticObject &obj) -> bool { + if (obj.data.size() > U16_MAX) { + errorstream << "StaticObjectList::serialize(): " + "object has excessive static data (" << obj.data.size() << + "), deleting it." << std::endl; + return true; + } + return false; + }; + for (auto it = m_stored.begin(); it != m_stored.end(); ) { + if (problematic(*it)) + it = m_stored.erase(it); + else + it++; + } + for (auto it = m_active.begin(); it != m_active.end(); ) { + if (problematic(it->second)) + it = m_active.erase(it); + else + it++; + } + // version u8 version = 0; writeU8(os, version); |