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CVE-2026-46126 Linux CVE debrief

A vulnerability in the Linux kernel's RDMA/mana driver affects error handling during queue pair creation with RSS (Receive Side Scaling). The bug involves incorrect cleanup logic in `mana_ib_create_qp_rss()` that can lead to resource leaks or double-decrement issues when unwinding the Work Queue (WQ) table on failure paths. Specifically, a double `i--` decrement occurs on the first failure path due to the while loop structure, and if `mana_ib_install_cq_cb()` fails, the prior `mana_create_wq_obj()` call is not properly undone. The vulnerability was resolved by correcting the error unwind flow to properly clean up WQ table entries without double-decrementing and ensuring all allocated resources are released on failure paths.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-28
Original CVE updated
2026-06-24
Advisory published
2026-05-28
Advisory updated
2026-06-24

Who should care

Organizations running Linux systems with Microsoft Azure Network Adapter (MANA) RDMA hardware, cloud providers offering RDMA-enabled instances, and kernel maintainers backporting stable fixes.

Technical summary

The vulnerability exists in the RDMA/mana driver's `mana_ib_create_qp_rss()` function, which creates queue pairs with RSS support. The error unwind logic contains two bugs: (1) a double decrement of index variable `i` on the first failure path due to both a while loop decrement and an explicit `i--`, and (2) failure to undo `mana_create_wq_obj()` when `mana_ib_install_cq_cb()` fails because of the incorrect `i--` placement. These bugs can result in improper cleanup of Work Queue objects, potentially leading to resource leaks or inconsistent state. The fix removes the erroneous `i--` and corrects the unwind logic to properly release all allocated WQ objects on any failure path.

Defensive priority

medium

Recommended defensive actions

  • Review kernel version and apply stable kernel updates containing the fix commits
  • Monitor Linux distribution security advisories for backported patches
  • Assess systems using Microsoft Azure Network Adapter (MANA) RDMA functionality for exposure
  • Validate error handling paths in custom kernel modules utilizing similar WQ table patterns

Evidence notes

Vulnerability description sourced from official CVE record and NVD entry. Technical details derived from kernel commit messages referenced in NVD. Vendor identification marked as low confidence requiring review; 'Kernel' domain candidate noted.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-46126 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-46126

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

  • CVE-2026-46126 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-46126

    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/34ecf795692ee57c393109f4a24ccc313091e137

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/8f23eb6c50f1a4bf32fc4d62cfb9fc39e8e586cf

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/9a05a6798177e44dfbe18393be2c1ebb89ab06fd

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/bb9cb36eaefa4dcb7c0d9f7a01e5c739abdd53a8

    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.