# CVE-2026-98756: usb: cdns3: Fix NULL pointer dereference in cdns3_pci_probe

> A NULL pointer dereference in the Linux kernel's Cadence USBSS driver can cause a system crash during device probing.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-108803, BELL-CVE-2026-98756, DEBIAN-CVE-2026-98756, GHSA-r25x-m228-w665, UBUNTU-CVE-2026-98756

## What is CVE-2026-98756?

CVE-2026-98756 is a vulnerability in Linux, published on 18 Oct 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:

usb: cdns3: Fix NULL pointer dereference in cdns3_pci_probe

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.

## Which versions are affected by CVE-2026-98756?


## How do I fix CVE-2026-98756?

Apply the vendor's patch.

## Is CVE-2026-98756 being exploited?

There is no known exploitation of CVE-2026-98756 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98756 and fix it if it is affected.

What it is: CVE-2026-98756 is a vulnerability in Linux, published on 18 Oct 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-2026-98756 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-2026-98756/ (Markdown: https://insights.sbomify.com/CVE-2026-98756/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98756
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98756
- OSV: https://osv.dev/vulnerability/CVE-2026-98756

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98756/
Summaries are generated and may contain mistakes; the official description above is the record.