Add crossbeam-channel advisory re upstream MR #1187 (#2277)

Author: ijackson

crates/crossbeam-channel/RUSTSEC-0000-0000.md

@@ -0,0 +1,33 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "crossbeam-channel"
+date = "2025-04-08"
+url = "https://github.com/crossbeam-rs/crossbeam/pull/1187"
+categories = ["memory-corruption"]
+keywords = ["race"]
+aliases = ["TROVE-2025-013"]
+
+[versions]
+patched = [">= 0.5.15"]
+unaffected = ["<= 0.5.11"]
+```
+
+# crossbeam-channel: double free on Drop
+
+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