# CVE-2026-99197: Linux kernel mv643xx_eth NULL pointer dereference in PHY probe

Source: https://junglewise.ai/threats/cve-2026-99197-in-the-linux-kernel-the-following-vulnerability-has-been-resolved  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-28. Updated: 2026-10-28  
License: CC BY 4.0 with a link back

CVE-2026-99197 · Severity: info · Published 2026-10-28

The Linux kernel's mv643xx Ethernet driver crashes with a NULL pointer error during network device initialization when CONFIG_NET_SHAPER is enabled. An attacker with the ability to trigger device probe operations could cause a denial of service, though this typically requires local access or control over device hotplug events.

Technologies: [Linux Kernel](https://junglewise.ai/threats/technologies/kernel). Vendors: [Linux](https://junglewise.ai/threats/vendors/linux).

## Quick answers

**Is CVE-2026-99197 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-99197 being exploited in the wild.

**How severe is CVE-2026-99197?** Informational severity, published 28 October 2026.

**Which products and versions are affected?** Linux Kernel affected versions include those with CONFIG_NET_SHAPER enabled and commit ded86da4bbb7 or later.

**Is there a fix for CVE-2026-99197?** A patch was published on 2026-10-15: upstream commit a3eef3d2cca032d8768b5eb07aab0f46b79bfd8a Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-99197 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-99197?** Check whether you run Linux Kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The mv643xx_eth_probe() function attempts to attach a PHY before initializing the device's netdev_ops structure. Since commit ded86da4bbb7, phy_attach_direct() now reads dev->netdev_ops through netdev_need_ops_lock() when CONFIG_NET_SHAPER is enabled, causing a NULL pointer dereference. The fix reorders initialization to assign netdev_ops before PHY attachment.

## Affected products

- Linux kernel affected versions include those with CONFIG_NET_SHAPER enabled and commit ded86da4bbb7 or later

## Timeline

- 2026-10-28: disclosed
- 2026-10-15: patched: upstream commit a3eef3d2cca032d8768b5eb07aab0f46b79bfd8a

## References

- [https://git.kernel.org/stable/c/a3eef3d2cca032d8768b5eb07aab0f46b79bfd8a](https://git.kernel.org/stable/c/a3eef3d2cca032d8768b5eb07aab0f46b79bfd8a)
- [https://git.kernel.org/stable/c/bfb1ca89e9f6efa26c8a4a5b9de46541a222abc9](https://git.kernel.org/stable/c/bfb1ca89e9f6efa26c8a4a5b9de46541a222abc9)

## Related threats

- [Linux kernel xen-netback double unmap memory corruption](https://junglewise.ai/threats/cve-2026-99287-in-the-linux-kernel-the-following-vulnerability-has-been-resolved)
- [Linux kernel PMC uninitialized clock rate in 32-bit Tegra](https://junglewise.ai/threats/cve-2026-99259-in-the-linux-kernel-the-following-vulnerability-has-been-resolved)
- [Linux kernel x86 Hyper-V memory access violation](https://junglewise.ai/threats/cve-2026-99258-in-the-linux-kernel-the-following-vulnerability-has-been-resolved)
- [Linux kernel io_uring signal loss in worker exit](https://junglewise.ai/threats/cve-2026-99228-in-the-linux-kernel-the-following-vulnerability-has-been-resolved)
- [Linux kernel unicode map use-after-free in path lookup](https://junglewise.ai/threats/cve-2026-99180-in-the-linux-kernel-the-following-vulnerability-has-been-resolved)