CVE-2026-64465

What the bug is

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.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/usb/host/xhci.c

What this is

USB XHCI DRIVERMAINTAINERS section matched on drivers/usb/host/xhci* · linux-usb@vger.kernel.org · Supported

Check it on the machine

grep -wE 'CONFIG_OF|CONFIG_PCI|CONFIG_USB|CONFIG_USB_EHCI_HCD|CONFIG_USB_FHCI_HCD|CONFIG_USB_FOTG210_HCD|CONFIG_USB_FSL_USB2|CONFIG_USB_GADGET|CONFIG_USB_ISP116X_HCD|CONFIG_USB_ISP1362_HCD|CONFIG_USB_MAX3421_HCD|CONFIG_USB_OHCI_HCD|CONFIG_USB_PCI|CONFIG_USB_PHY|CONFIG_USB_R8A66597_HCD|CONFIG_USB_SL811_HCD|CONFIG_USB_SUPPORT|CONFIG_USB_U132_HCD|CONFIG_USB_UHCI_HCD|CONFIG_USB_XEN_HCD|CONFIG_USB_XHCI_HCD' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

Show whether Debian builds this, per release

Debian does not build this code. In 5 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.

• bookworm, trixie, forky, sid, bookworm · linux-6.12n

n

not enabled on any flavour - this release does not build the code

Build switches

CONFIG_OF, CONFIG_PCI, CONFIG_USB, CONFIG_USB_EHCI_HCD, CONFIG_USB_FHCI_HCD, CONFIG_USB_FOTG210_HCD, CONFIG_USB_FSL_USB2, CONFIG_USB_GADGET, CONFIG_USB_ISP116X_HCD, CONFIG_USB_ISP1362_HCD, CONFIG_USB_MAX3421_HCD, CONFIG_USB_OHCI_HCD, CONFIG_USB_PCI, CONFIG_USB_PHY, CONFIG_USB_R8A66597_HCD, CONFIG_USB_SL811_HCD, CONFIG_USB_SUPPORT, CONFIG_USB_U132_HCD, CONFIG_USB_UHCI_HCD, CONFIG_USB_XEN_HCD, CONFIG_USB_XHCI_HCD

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-07-25 (3 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 7.5% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/usb

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
2.6.35	5.10.261	e623e4a203f5
2.6.35	5.15.212	d107eb316144
2.6.35	6.1.178	1e45aa722c4c
2.6.35	6.6.145	10666ac9c552
2.6.35	6.12.96	f7b022ae0768
2.6.35	6.18.39	f90586129cf9
2.6.35	7.1.4	93cd037da94f
2.6.35	7.2	42c37c4b75d3

Debian advisories