# CVE-2026-74285: net: Stop leased rxq before uninstalling its memory provider

> A race condition in Linux kernel network queue teardown allows DMA to stale addresses, potentially causing memory corruption or crashes.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-74285, GHSA-v8cx-r8w6-r2xr, UBUNTU-CVE-2026-74285

## What is CVE-2026-74285?

CVE-2026-74285 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net: Stop leased rxq before uninstalling its memory provider

netif_rxq_cleanup_unlease() tears down the memory provider that was
installed on a physical RX queue through a netkit queue lease. It
currently revokes the provider's DMA mappings before stopping the
physical queue:

  __netif_mp_uninstall_rxq(virt_rxq, p);            /* DMA unmap */
  __netif_mp_close_rxq(phys_rxq->dev, rxq_idx, p);  /* queue stop */

This inverts the ordering used by the regular teardown paths (normal
device unregister and the io_uring zcrx close path), which stop the
queue before revoking the provider's mappings.

With the physical queue still live, its NAPI can keep consuming
net_iov entries from the page_pool alloc cache after the
__netif_mp_uninstall_rxq() has already cleared their dma_addr,
opening a window for the device to DMA to a stale or zero address.

Fix it by swapping the two calls so the queue is stopped (and its
NAPI quiesced) before the provider is uninstalled. No functional
regression was observed across repeated runs of the nk_qlease.py
HW selftest, which exercises the lease teardown path; this was
tested against fbnic QEMU emulation.

## Which versions are affected by CVE-2026-74285?


## How do I fix CVE-2026-74285?

Apply the vendor's patch.

## Is CVE-2026-74285 being exploited?

There is no known exploitation of CVE-2026-74285 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74285 and fix it if it is affected.

What it is: CVE-2026-74285 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74285 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74285/ (Markdown: https://insights.sbomify.com/CVE-2026-74285/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74285
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74285
- OSV: https://osv.dev/vulnerability/CVE-2026-74285

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74285/
Summaries are generated and may contain mistakes; the official description above is the record.