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Fencer Intel
high —

GHSA-rvr2-r3pv-5m4p json

oneshot has potential Use After Free when used asynchronously

published 9mo ago modified 2mo ago also RUSTSEC-2026-0005

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

There is a race condition that can lead to a use-after-free if a `oneshot::Receiver` is polled but then dropped instead of polled to completion. This could happen if the receiver future was cancelled while receiving, for example by being wrapped in a timeout future or similar.

When the `Receiver` is polled (`Future::poll`) it writes a waker to the channel and sets it to the `RECEIVING` state. If the `Receiver` was then dropped (instead of polled to completion), the `Drop` implementation on `Receiver` unconditionally swapped the channel state to `DISCONNECTED` and only after doing so it read back its waker from the heap allocation and dropped it. The problem is that the `DISCONNECTED` state could be observed by the `Sender`, which would lead to it deallocating the channel heap memory. If the `Sender` manage to free the channel before the `Receiver` managed to proceed to dropping the waker, then the `Receiver` would read from the freed channel memory (Use After Free).

The fix was submitted in https://github.com/faern/oneshot/pull/74 and published as part of `oneshot` version `0.1.12`.

Patch / fix

  • crates.io oneshot 0.1.12

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Affected packages

ecosystem package affected fixed in
crates.io oneshot
<0.1.12
>=0.1.2-0, <0.1.12
0.1.12

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
  • CWE-416 Use After Free

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.