CVE-2026-68419: RDMA/irdma: Prevent rereg_mr for non-mem regions

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-10 · updated 2026-10-19
Weakness: CWE-20

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.

Affected products

Linux kernel: from 6.6.120 before 6.6.148; 6.7 — fixed in 6.6.148, 7.2

How to fix

Upgrade to a fixed version: Linux kernel 6.6.148, 7.2. Check the vendor advisory for mitigations.

References

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