GHSA-pg9f-39pc-qf8g
crossbeam-channel Vulnerable to Double Free on Drop
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| crates.io | crossbeam-channel | >= 0.5.12, < 0.5.15 | 0.5.15 |
Details
As written in the advisory (Markdown source, shown as plain text).
The internal `Channel` type's `Drop` method has a race
which could, in some circumstances, lead to a double-free.
This could result in memory corruption.
Quoting from the
[upstream description in merge request \#1187](https://github.com/crossbeam-rs/crossbeam/pull/1187#issue-2980761131):
> The problem lies in the fact that `dicard_all_messages` contained two paths that could lead to `head.block` being read but only one of them would swap the value. This meant that `dicard_all_messages` could end up observing a non-null block pointer (and therefore attempting to free it) without setting `head.block` to null. This would then lead to `Channel::drop` making a second attempt at dropping the same pointer.
The bug was introduced while fixing a memory leak, in
upstream [MR \#1084](https://github.com/crossbeam-rs/crossbeam/pull/1084),
first published in 0.5.12.
The fix is in
upstream [MR \#1187](https://github.com/crossbeam-rs/crossbeam/pull/1187)
and has been published in 0.5.15
References
External links from the advisory. They lead to third-party sites.