mirrors/actix-web
1
0
Fork 0
mirror of https://github.com/actix/actix-web.git synced 2024-12-23 00:26:34 +00:00
Code Issues Projects Releases Wiki Activity

Fix loophole in soundness of __private_get_type_id__ (#2199)

Browse source
This commit is contained in:
Aaron Hill 2021-05-05 06:16:12 -04:00 committed by GitHub
parent c17662fe39
commit dd1a3e7675
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 14 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
actix-http/src/macros.rs
View file

@ -15,8 +15,15 @@ macro_rules! downcast_get_type_id {
/// making it impossible for safe code to construct outside of /// making it impossible for safe code to construct outside of
/// this module. This ensures that safe code cannot violate /// this module. This ensures that safe code cannot violate
/// type-safety by implementing this method. /// type-safety by implementing this method.
///
/// We also take `PrivateHelper` as a parameter, to ensure that
/// safe code cannot obtain a `PrivateHelper` instance by
/// delegating to an existing implementation of `__private_get_type_id__`
#[doc(hidden)] #[doc(hidden)]
fn __private_get_type_id__(&self) -> (std::any::TypeId, PrivateHelper) fn __private_get_type_id__(
&self,
_: PrivateHelper,
) -> (std::any::TypeId, PrivateHelper)
where where
Self: 'static, Self: 'static,
{ {
@ -39,7 +46,9 @@ macro_rules! downcast {
impl dyn $name + 'static { impl dyn $name + 'static {
/// Downcasts generic body to a specific type. /// Downcasts generic body to a specific type.
pub fn downcast_ref<T: $name + 'static>(&self) -> Option<&T> { pub fn downcast_ref<T: $name + 'static>(&self) -> Option<&T> {
if self.__private_get_type_id__().0 == std::any::TypeId::of::<T>() { if self.__private_get_type_id__(PrivateHelper(())).0
== std::any::TypeId::of::<T>()
{
// SAFETY: external crates cannot override the default // SAFETY: external crates cannot override the default
// implementation of `__private_get_type_id__`, since // implementation of `__private_get_type_id__`, since
// it requires returning a private type. We can therefore // it requires returning a private type. We can therefore
@ -53,7 +62,9 @@ macro_rules! downcast {
/// Downcasts a generic body to a mutable specific type. /// Downcasts a generic body to a mutable specific type.
pub fn downcast_mut<T: $name + 'static>(&mut self) -> Option<&mut T> { pub fn downcast_mut<T: $name + 'static>(&mut self) -> Option<&mut T> {
if self.__private_get_type_id__().0 == std::any::TypeId::of::<T>() { if self.__private_get_type_id__(PrivateHelper(())).0
== std::any::TypeId::of::<T>()
{
// SAFETY: external crates cannot override the default // SAFETY: external crates cannot override the default
// implementation of `__private_get_type_id__`, since // implementation of `__private_get_type_id__`, since
// it requires returning a private type. We can therefore // it requires returning a private type. We can therefore