CVE-2026-74396

Received Received - Intake

Memory Leak in Linux Kernel RDMA/mlx5 Driver

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure mlx5r_umr_update_xlt() allocates and DMA maps an XLT buffer with mlx5r_umr_create_xlt(). The buffer is released by the common cleanup path through mlx5r_umr_unmap_free_xlt(). After mlx5_odp_populate_xlt() became fallible, its error path returned directly and skipped that cleanup. This leaks the XLT DMA mapping and buffer. If the emergency XLT page was used, it also leaves xlt_emergency_page_mutex locked. Break out of the loop so execution falls through the existing cleanup path.

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74396

EUVD

EUVD-2026-59543

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*
linux_kernel	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a memory management issue in the RDMA subsystem for Mellanox devices. When populating an XLT buffer fails, the cleanup process is skipped, causing a leak of the DMA mapping and buffer. If the emergency XLT page was used, it also leaves a mutex locked.

Detection Guidance

This vulnerability is specific to the Linux kernel's RDMA/mlx5 driver and involves memory leaks during XLT buffer cleanup. Detection requires checking kernel logs for RDMA-related errors or memory leaks after UMR operations. Commands like dmesg | grep mlx5 or journalctl -k | grep mlx5 may help identify issues.

Impact Analysis

This vulnerability could lead to resource leaks and potential system instability. It may cause memory exhaustion or deadlocks if the emergency XLT page mutex remains locked, affecting system performance and reliability.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it is a low-level kernel memory management issue in the Linux RDMA subsystem. Compliance risks would only arise if exploitation led to data breaches or unauthorized access, which is not indicated by the provided details.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the RDMA/mlx5 UMR XLT cleanup issue. Check your distribution's security advisories for kernel updates addressing CVE-2026-74396.

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