Linux Kernel up to 6.18.32/7.0.9 fwctl cxl_pci_driver_init null pointer dereference

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.18.32/7.0.9 and classified as critical. This affects the function cxl_pci_driver_init of the component fwctl. Performing a manipulation results in null pointer dereference. This vulnerability is known as CVE-2026-53042. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.32/7.0.9. It has been classified as critical. This affects the function cxl_pci_driver_init of the component fwctl. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: fwctl: Fix class init ordering to avoid NULL pointer dereference on device removal CXL is linked before fwctl in drivers/Makefile. Both use `module_init, so `cxl_pci_driver_init()` runs first. When `cxl_pci_probe()` calls `fwctl_register()` and then `device_add()`, fwctl_class is not yet registered because fwctl_init() hasn't run, causing `class_to_subsys()` to return NULL and skip knode_class initialization. On device removal, `class_to_subsys()` returns non-NULL, and `device_del()` calls `klist_del()` on the uninitialized knode, triggering a NULL pointer dereference.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-53042 since 06/09/2026. Technical details are known, but no exploit is available.

Upgrading to version 6.18.33 or 7.0.10 eliminates this vulnerability. Applying the patch a28f56988c8e5bb9375806a5cfb0bf54d662ae3f/1075f2f590fdac147f8b8010c35b606564b5c7d7/a55f80233f384dc89ef3425b2e1dd0e6d44bcf29 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.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3
• 7.0.4
• 7.0.5
• 7.0.6
• 7.0.7
• 7.0.8
• 7.0.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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