RUSTSEC-2020-0072

GenericMutexGuard allows data races of non-Sync types across threads

Reported

October 31, 2020

Issued

November 18, 2020 (last modified: June 13, 2023)

Package

futures-intrusive (crates.io)

Type

INFO Unsound

Categories

Keywords

#concurrency

Aliases

References

https://github.com/Matthias247/futures-intrusive/issues/53

CVSS Score

5.5 MEDIUM

CVSS Details

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Patched

>=0.4.0

Description

GenericMutexGuard<T> was given the Sync auto trait as long as T is Send due to its contained members. However, since the guard is supposed to represent an acquired lock and allows concurrent access to the underlying data from different threads, it should only be Sync when the underlying data is.

This is a soundness issue and allows data races, potentially leading to crashes and segfaults from safe Rust code.

The flaw was corrected by adding a T: Send + Sync bound for GenericMutexGuard's Sync trait.

This bug is similar to one in std::sync::Mutex.

Advisory available under CC0-1.0 license.