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CVE-2026-46188 Linux CVE debrief

A NULL pointer dereference vulnerability exists in the Linux kernel's octeon_ep_vf driver. The function `napi_build_skb()` can return NULL on memory allocation failure, but `__octep_vf_oq_process_rx()` uses this return value without validation in both single-buffer and multi-fragment receive paths. This flaw could lead to kernel crashes when the system is under memory pressure. The vulnerability was resolved by adding NULL checks after both `napi_build_skb()` calls, with proper descriptor advancement and fragment cleanup on failure paths.

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 Linux systems with Cavium/Marvell Octeon network adapters using SR-IOV virtual functions; cloud providers and hosting environments with high-density virtualized networking; kernel maintainers and distribution security teams

Technical summary

The octeon_ep_vf virtual function driver for Cavium/Marvell Octeon network adapters fails to check for NULL return from `napi_build_skb()` in its receive packet processing routine `__octep_vf_oq_process_rx()`. This function is invoked in both single-buffer and multi-fragment receive paths. When memory allocation fails under pressure, the subsequent dereference of the NULL skb pointer triggers a kernel oops or panic. The fix introduces explicit NULL checks with proper cleanup: advancing receive descriptors and consuming any remaining fragments to maintain ring consistency before returning.

Defensive priority

medium

Recommended defensive actions

  • Apply kernel patches from stable tree commits when available for your distribution
  • Monitor vendor security advisories for updated kernel packages
  • Consider memory pressure monitoring on systems using Cavium Octeon network adapters
  • Review system logs for kernel NULL pointer dereference events indicating potential exploitation attempts

Evidence notes

Vulnerability description confirms NULL pointer dereference in octeon_ep_vf driver. Four kernel.org stable tree commits provided as references. CVE published 2026-05-28 with status 'Awaiting Analysis'. No CVSS score assigned by NVD at time of disclosure.

Official resources

2026-05-28