Linux Kernel up to 6.18.9 Nvme Driver dma_needs_unmap uninitialized pointer

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.18.9 and classified as critical. This impacts the function dma_needs_unmap of the component Nvme Driver. This manipulation causes uninitialized pointer. The identification of this vulnerability is CVE-2026-23174. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.18.9. Affected by this vulnerability is the function dma_needs_unmap of the component Nvme Driver. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. The CWE definition for the vulnerability is CWE-824. The product accesses or uses a pointer that has not been initialized. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: nvme-pci: handle changing device dma map requirements The initial state of dma_needs_unmap may be false, but change to true while mapping the data iterator. Enabling swiotlb is one such case that can change the result. The nvme driver needs to save the mapped dma vectors to be unmapped later, so allocate as needed during iteration rather than assume it was always allocated at the beginning. This fixes a NULL dereference from accessing an uninitialized dma_vecs when the device dma unmapping requirements change mid-iteration.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-23174 since 01/13/2026. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/13/2026).

The vulnerability scanner Nessus provides a plugin with the ID 299098 (Linux Distros Unpatched Vulnerability : CVE-2026-23174), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.10 eliminates this vulnerability. Applying the patch f3ed399e9aa6f36e92d2d0fe88b387915e9705fe/071be3b0b6575d45be9df9c5b612f5882bfc5e88 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (299098) and CERT Bund (WID-SEC-2026-0421). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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