RUSTSEC-2025-0024: crossbeam-channel: double free on Drop

[github-actions[bot]]

crossbeam-channel: double free on Drop

Details
Package	crossbeam-channel
Version	0.5.13
URL	https://github.com/crossbeam-rs/crossbeam/pull/1187
Date	2025-04-08
Patched versions	>=0.5.15
Unaffected versions	<=0.5.11

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:

> 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, first published in 0.5.12.

The fix is in upstream MR \#1187 and has been published in 0.5.15

See advisory page for additional details.