Affected versions of the crate had a Send/Sync implementation for MappedMutexGuard that only considered variance on T, while MappedMutexGuard dereferenced to U.
This could of led to data races in safe Rust code when a closure used in MutexGuard::map() returns U that is unrelated to T.
The issue was fixed by fixing Send
and Sync
implementations, and by adding a PhantomData<&'a mut U>
marker to the MappedMutexGuard
type to tell the compiler that the guard is over
U too.
CPE | Name | Operator | Version |
---|---|---|---|
futures-util | ge | 0.3.2 | |
futures-util | lt | 0.3.7 |