CVE-2026-93037 in Linux
Summary
by MITRE • 09/17/2026
In the Linux kernel, the following vulnerability has been resolved:
RDMA/hfi1: Propagate sdma_txinit_ahg() errors
set_txreq_header_ahg() ignores the return value of sdma_txinit_ahg().
If sdma_txinit_ahg() fails, it returns before initializing tx->txreq. However, set_txreq_header_ahg() ignores the error and returns the AHG change count, causing the caller to continue processing the request as though initialization had succeeded.
Propagate sdma_txinit_ahg() failures to the caller and abort request processing when initialization fails.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
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Analysis
by VulDB Data Team • 09/17/2026
The vulnerability identified in the Linux kernel's RDMA/hfi1 driver represents a critical error handling deficiency within the InfiniBand hardware interface subsystem. Specifically, the function set_txreq_header_ahg() fails to check the return value of sdma_txinit_ahg(), which is responsible for initializing transmission request address handle groups. This oversight creates a scenario where initialization failures are silently ignored, leading to potential instability or undefined behavior in high-performance computing environments that rely on reliable data transfer mechanisms. The issue was discovered using static analysis tools from the Linux Verification Center, highlighting the importance of rigorous code verification processes in kernel development.
From a technical perspective, sdma_txinit_ahg() is designed to set up essential structures for direct memory access transmission requests. When this function encounters an error during initialization, it returns early without populating critical fields within the tx->txreq structure. However, because set_txreq_header_ahg() does not validate this return status, it proceeds to execute subsequent logic that assumes successful initialization. The function then returns a value representing the AHG change count, which signals success to the calling functions in the driver stack. This misrepresentation of state causes the system to treat an uninitialized or partially initialized request as valid, potentially leading to memory corruption, data loss, or kernel panics when the hardware attempts to process these malformed requests.
The operational impact of this vulnerability is significant for systems utilizing Intel Omni-Path adapters powered by the hfi1 driver. In production environments, particularly those running high-throughput workloads such as large-scale machine learning training clusters or distributed databases, the propagation of uninitialized data can result in unpredictable system behavior. Attackers with local access could potentially exploit this flaw to trigger denial-of-service conditions by forcing repeated initialization failures that are ignored by the kernel logic. Furthermore, if the uninitialized memory contains sensitive information from previous operations, there is a theoretical risk of information disclosure, although the primary concern remains system stability and integrity due to improper state management in the driver's transmission pipeline.
This flaw aligns with CWE-252, which describes unchecked return values as a common cause of software vulnerabilities. By failing to verify that sdma_txinit_ahg() completed its task successfully, the code violates fundamental principles of defensive programming and robust error handling. In terms of attack vectors, this issue does not directly facilitate privilege escalation but serves as an enabler for local denial-of-service attacks against critical infrastructure components. It reflects a gap in the validation layer that should exist before hardware-specific operations are committed to execution queues.
Mitigation strategies primarily involve applying the upstream kernel patch that corrects this logic by propagating errors from sdma_txinit_ahg() back through set_txreq_header_ahg(). System administrators managing affected systems should ensure their kernels are updated to versions where this fix is integrated. For organizations unable to immediately update, monitoring system logs for RDMA-related errors and ensuring strict resource limits on network interfaces can help mitigate the impact of potential crashes. Long-term remediation requires integrating static analysis tools like SVACE into continuous integration pipelines to catch such unchecked return value issues before they reach production codebases.