CVE-2024-43806

Technical Description

Rustix is a set of safe Rust bindings to POSIX-ish APIs. When using `rustix::fs::Dir` using the `linux_raw` backend, it's possible for the iterator to "get stuck" when an IO error is encountered. Combined with a memory over-allocation issue in `rustix::fs::Dir::read_more`, this can cause quick and unbounded memory explosion (gigabytes in a few seconds if used on a hot path) and eventually lead to an OOM crash of the application. The symptoms were initially discovered in https://github.com/imsnif/bandwhich/issues/284. That post has lots of details of our investigation. Full details can be read on the GHSA-c827-hfw6-qwvm repo advisory. If a program tries to access a directory with its file descriptor after the file has been unlinked (or any other action that leaves the `Dir` iterator in the stuck state), and the implementation does not break after seeing an error, it can cause a memory explosion. As an example, Linux's various virtual file systems (e.g. `/proc`, `/sys`) can contain direc

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References