What’s Vulnerable › Vulnerabilities

CVE-2026-53042: fwctl: Fix class init ordering to avoid NULL pointer dereference on device removal

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-24 · updated 2026-07-14
• Weakness: CWE-824

Description

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.

Affected products

• Linux kernel: from 6.15 before 6.18.33; from 6.19 before 7.0.10 — fixed in 6.18.33, 7.0.10

How to fix

Upgrade to a fixed version: Linux kernel 6.18.33, 7.0.10. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/1075f2f590fdac147f8b8010c35b606564b5c7d7
• https://git.kernel.org/stable/c/a28f56988c8e5bb9375806a5cfb0bf54d662ae3f
• https://git.kernel.org/stable/c/a55f80233f384dc89ef3425b2e1dd0e6d44bcf29

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