CVE-2026-68419
Received Received - Intake

RDMA rereg_mr Denial of Service in Linux Kernel

Publication date: 2026-08-10

Last updated on: 2026-08-10

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: RDMA/irdma: Prevent rereg_mr for non-mem regions When a QP/CQ/SRQ is created, a two step process is used where the buffer is allocated in userspace and explicitly registered with the normal reg_mr mechanism prior to creating the actual QP/CQ/SRQ object. These special registrations are indicated via an ABI field so the driver knows that they do not have a valid mkey and to skip the actual CQP command submission. Since these are real MR objects from the core's perspective, it is possible for a user application to invoke rereg_mr on them and cause a real CQP op to be emitted with the zero-initialized mkey value of 0. Fix this by preventing rereg_mr on these special regions.

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Meta Information

Published
2026-08-10
Last Modified
2026-08-10
Generated
2026-08-10
AI Q&A
2026-08-10
EPSS Evaluated
N/A
NVD
CVE-2026-68419
EUVD
EUVD-2026-55605

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flaw in the RDMA/irdma driver where special memory regions created during QP/CQ/SRQ setup can be incorrectly reregistered. Normally these regions use a zero mkey value and skip CQP commands, but a user application can trigger a rereg_mr operation, causing the driver to send an invalid CQP command with mkey=0. The fix prevents rereg_mr on these special regions.

Impact Analysis

This vulnerability could allow a local attacker to cause a denial of service or potentially escalate privileges by triggering invalid memory operations in the RDMA subsystem. Systems using affected RDMA/irdma drivers may experience crashes or instability.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the RDMA/irdma rereg_mr vulnerability. Monitor vendor advisories for kernel updates specific to your distribution.

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