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CVE-2026-45926 Linux CVE debrief

A memory leak vulnerability exists in the Linux kernel's Rust PWM (Pulse Width Modulation) subsystem. When initializing a PWM chip using `pwmchip_alloc()`, the allocated device holds an initial reference that must be released on all error paths. If `__pinned_init()` fails during initialization, the error path returns without calling `pwmchip_put()`, resulting in a memory leak of the allocated `pwm_chip` structure. This vulnerability affects kernel versions where the Rust PWM bindings are present and has been resolved by ensuring proper cleanup on initialization failure.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-27
Original CVE updated
2026-06-25
Advisory published
2026-05-27
Advisory updated
2026-06-25

Who should care

Linux kernel maintainers, embedded systems developers using PWM functionality, organizations running custom kernel builds with Rust support, and security teams tracking kernel memory safety issues.

Technical summary

The vulnerability is located in the Rust bindings for the Linux kernel PWM subsystem. The `pwmchip_alloc()` function allocates a PWM chip structure with an initial reference count. The `__pinned_init()` function performs additional initialization. If this initialization fails, the original error path did not decrement the reference count via `pwmchip_put()`, causing the allocated memory to leak. The fix adds the missing `pwmchip_put()` call to the error path, ensuring proper resource cleanup regardless of initialization success or failure.

Defensive priority

medium

Recommended defensive actions

  • Review and apply the referenced kernel commits to affected systems
  • Verify Rust PWM subsystem is updated in custom kernel builds
  • Monitor kernel stable releases for backported fixes
  • Audit error handling paths in Rust kernel code for similar patterns

Evidence notes

The vulnerability description indicates this is a memory leak in error handling paths within the Rust PWM subsystem. The fix ensures that `pwmchip_put()` is called when `__pinned_init()` fails, properly releasing the reference obtained during `pwmchip_alloc()`. Two kernel commits are referenced as resolution sources.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-45926 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-45926

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-45926 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-45926

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a2633dc243c35754a0c2270131d8a199c987c9bf

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/baa8b7097d9cc68ff85819cf683972a58c2ce32b

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.