# CVE-2026-64465: usb: xhci: Fix sleep in atomic context in xhci_free_streams()

> A local attacker with physical access can cause a kernel crash by disconnecting a USB device with active stream endpoints, leading to denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 25 Jul 2026
- **Updated:** 17 Aug 2026
- **Also known as:** AZL-93912, BELL-CVE-2026-64465, DEBIAN-CVE-2026-64465, GHSA-5wmv-5wg4-7mv5, ROOT-OS-UBUNTU-2204-CVE-2026-64465, UBUNTU-CVE-2026-64465

## What is CVE-2026-64465?

CVE-2026-64465 is a denial of service vulnerability in Linux, published on 25 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

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

usb: xhci: Fix sleep in atomic context in xhci_free_streams()

When a USB device with active stream endpoints is disconnected,
xhci_free_streams() is called from the hub_event workqueue to
free the stream resources.  It calls xhci_free_stream_info()
while holding xhci->lock with irqs disabled.

xhci_free_stream_info() invokes xhci_free_stream_ctx(), which
calls dma_free_coherent() for large stream context arrays.

dma_free_coherent() can sleep (e.g. via vunmap), triggering
a BUG when called from atomic context.

Call trace:
 dma_free_attrs+0x174/0x220
 xhci_free_stream_info+0xd0/0x11c
 xhci_free_streams+0x278/0x37c
 usb_free_streams+0x98/0xc0
 usb_unbind_interface+0x1b8/0x2f8
 device_release_driver_internal+0x1d4/0x2cc
 device_release_driver+0x18/0x28
 bus_remove_device+0x160/0x1a4
 device_del+0x1ec/0x350
 usb_disable_device+0x98/0x214
 usb_disconnect+0xf0/0x35c
 hub_event+0xab4/0x19ec
 process_one_work+0x278/0x63c

Fix this by saving the stream_info pointers and clearing the
ep references under the lock, then calling xhci_free_stream_info()
outside the lock where sleeping is allowed.

## Which versions are affected by CVE-2026-64465?


## How do I fix CVE-2026-64465?

Apply the vendor's patch.

## Is CVE-2026-64465 being exploited?

There is no known exploitation of CVE-2026-64465 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64465 and fix it if it is affected.

What it is: CVE-2026-64465 is a denial of service vulnerability in Linux, published on 25 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-64465 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-2026-64465/ (Markdown: https://insights.sbomify.com/CVE-2026-64465/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64465
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64465
- OSV: https://osv.dev/vulnerability/CVE-2026-64465

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64465/
Summaries are generated and may contain mistakes; the official description above is the record.