CVE-2026-98756

What the bug is

The Cadence USBSS controller is a two-function PCI device. The first probed function allocates the driver data and stores it with pci_set_drvdata(), while the second function reuses it via pci_get_drvdata() when pci_is_enabled() reports that the first function has already been probed. When the second function is probed while the first one has been enabled but has not yet set its driver data, pci_get_drvdata() returns NULL, and the subsequent wrap->devfn assignment dereferences a NULL pointer and crashes the kernel. logs: Call trace: cdns3_pci_probe+0xa4/0x300 local_pci_probe+0x44/0xa8 pci_call_probe+0x54/0x158 pci_device_probe+0x84/0x100 really_probe+0x184/0x3d0 __driver_probe_device+0x80/0x178 driver_probe_device+0x44/0xe8 __driver_attach+0xec/0x1f8 bus_for_each_dev+0x7c/0xe0 driver_attach+0x28/0x38 bus_add_driver+0x110/0x238 driver_register+0x64/0x128 __pci_register_driver+0x50/0x60 cdns3_pci_driver_init+0x28/0x38 do_one_initcall+0x5c/0x280 do_initcalls+0x104/0x1d8 kernel_init_freeable+0x140/0x218 kernel_init+0x28/0x1f8 ret_from_fork+0x10/0x20 Return -EPROBE_DEFER in this case so that probing is retried after the first function has completed its probe.

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/cdns3/cdns3-pci-wrap.c

What this is

CADENCE USB3 DRD IP DRIVERMAINTAINERS section matched on drivers/usb/cdns3/ · linux-usb@vger.kernel.org · Maintained

Kernel module

cdns3_pci_wrap

Check it on the machine

grep -wE 'CONFIG_OF|CONFIG_PCI|CONFIG_USB|CONFIG_USB_CDNS3|CONFIG_USB_CDNS3_PCI_WRAP|CONFIG_USB_CDNSP_PCI|CONFIG_USB_CDNS_SUPPORT|CONFIG_USB_GADGET|CONFIG_USB_PHY|CONFIG_USB_SUPPORT' /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.

lsmod | grep -w cdns3_pci_wrap

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian does not build this code in 2 releases. It does build it in 2 releases, so the answer depends on which release the machine runs.

• bookworm, trixien
• forky, sidMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x

n

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

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_OF, CONFIG_PCI, CONFIG_USB, CONFIG_USB_CDNS3, CONFIG_USB_CDNS3_PCI_WRAP, CONFIG_USB_CDNSP_PCI, CONFIG_USB_CDNS_SUPPORT, CONFIG_USB_GADGET, CONFIG_USB_PHY, CONFIG_USB_SUPPORT

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

2026-10-18 (today)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

not scored

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
5.4	6.12.113	549c04df02f1
5.4	6.18.56	d16046f1ace2
5.4	7.2.10	45b606418bae
5.4	7.3	e5052f2c5c73