# CVE-2026-64465: usb: xhci: Fix sleep in atomic context in xhci\_free\_streams()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-07-25 · Updated: 2026-08-17

## Affected

- Linux: version range not reported
- Linux: 2.6.35

## 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.

## 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.
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## 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/e623e4a203f56d5c57519a9a3cb29600551534ad
- https://git.kernel.org/stable/c/d107eb316144c5fb958486e7fe604cd7f1b35cda
- https://git.kernel.org/stable/c/1e45aa722c4ce5663e987102aac18c8ad6a83fdd
- https://git.kernel.org/stable/c/10666ac9c552990204e791af653abf8e9d9ff619
- https://git.kernel.org/stable/c/f7b022ae07685e7526fc39f387ce65b5d309dd3b
- https://git.kernel.org/stable/c/f90586129cf9e1fbdb718ef602eea3f15dc1c31c
- https://git.kernel.org/stable/c/93cd037da94fcb93183bfb2457e3a56d3eb4c8f4
- https://git.kernel.org/stable/c/42c37c4b75d38b51d84f31a8e29427f5e06a7c2a

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