Linux Kernel up to 6.18.1 qla2xxx qlt_free_cmd denial of service

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.1. It has been declared as critical. Affected is the function qlt_free_cmd of the component qla2xxx. Such manipulation leads to denial of service. This vulnerability is uniquely identified as CVE-2025-68745. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.1. Affected by this issue is the function qlt_free_cmd of the component qla2xxx. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Clear cmds after chip reset Commit aefed3e5548f ("scsi: qla2xxx: target: Fix offline port handling and host reset handling") caused two problems: 1. Commands sent to FW, after chip reset got stuck and never freed as FW is not going to respond to them anymore. 2. BUG_ON(cmd->sg_mapped) in qlt_free_cmd(). Commit 26f9ce53817a ("scsi: qla2xxx: Fix missed DMA unmap for aborted commands") attempted to fix this, but introduced another bug under different circumstances when two different CPUs were racing to call qlt_unmap_sg() at the same time: BUG_ON(!valid_dma_direction(dir)) in dma_unmap_sg_attrs(). So revert "scsi: qla2xxx: Fix missed DMA unmap for aborted commands" and partially revert "scsi: qla2xxx: target: Fix offline port handling and host reset handling" at __qla2x00_abort_all_cmds.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-68745 since 12/24/2025. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 279800 (Linux Distros Unpatched Vulnerability : CVE-2025-68745), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.2 or 6.19-rc1 eliminates this vulnerability. Applying the patch 5c1fb3fd05da3d55b8cbc42d7d660b313cbdc936/d46c69a087aa3d1513f7a78f871b80251ea0c1ae 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 (279800), EUVD (EUVD-2025-205217) and CERT Bund (WID-SEC-2025-2929). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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