Linux Kernel Vulnerability in RDMA IrDMA Affecting Memory Registration

CVE-2026-68419

What is CVE-2026-68419?

The vulnerability in the Linux kernel's RDMA/IrDMA subsystem arises from an improper handling of memory regions during the registration process. Specifically, when a Queue Pair (QP), Completion Queue (CQ), or Send/Receive Queue (SRQ) is established, the buffer is registered in userspace using the reg_mr mechanism. If these specialized regions are improperly managed, a user application may mistakenly invoke the rereg_mr command, potentially emitting an invalid Command Queue Pair (CQP) operation with a zero-initialized mkey. This flaw can lead to unexpected behavior and security vulnerabilities, thereby highlighting the need for thorough implementations of memory registration protocols in the kernel.

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