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PatchSiren cyber security CVE debrief

CVE-2026-46226 Linux CVE debrief

A use-after-free vulnerability exists in the Freescale (NXP) SPI controller driver for the Linux kernel. The flaw occurs during driver unbind, where DMA and other underlying resources are released before the SPI controller is deregistered. This ordering error can lead to invalid memory access if the controller or its consumers attempt to use those resources after they have been freed. The vulnerability is local in scope and requires privileges to unbind or remove the driver. The fix ensures proper teardown sequencing by deregistering the controller before releasing dependent resources.

Vendor
Linux
Product
Unknown
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-28
Original CVE updated
2026-05-28
Advisory published
2026-05-28
Advisory updated
2026-05-28

Who should care

Organizations running embedded Linux systems, industrial control systems, or IoT devices utilizing Freescale/NXP processors with SPI interfaces. Kernel maintainers and distribution security teams tracking stable kernel updates.

Technical summary

The fsl SPI driver in the Linux kernel fails to properly sequence controller deregistration during driver unbind, releasing DMA and other resources while the controller remains registered. This creates a use-after-free window where subsequent controller operations may access freed memory. The vulnerability is triggered during driver removal operations and affects systems with Freescale/NXP SPI hardware. The resolution reorders the teardown sequence to deregister the controller before releasing underlying resources, eliminating the race condition.

Defensive priority

medium

Recommended defensive actions

  • Apply kernel updates containing the fixed fsl SPI driver when available from your Linux distribution
  • Monitor NVD for CVSS scoring updates as the vulnerability is currently Awaiting Analysis
  • Review systems using Freescale/NXP SPI controllers for exposure to local privilege escalation scenarios
  • Validate driver unbind procedures in embedded/IoT deployments utilizing fsl-spi hardware

Evidence notes

The vulnerability description indicates a resource lifecycle management defect in the fsl SPI driver. The fix commit corrects the unbind sequence to prevent use-after-free conditions. No CVSS score has been assigned by NVD as of the modified date (2026-05-28T13:44:01.663Z). The vulnerability status is 'Awaiting Analysis' per NVD. Multiple stable kernel branches received backported fixes as evidenced by five distinct kernel.org stable commit references.

Official resources

2026-05-28