CVE-2026-80874 in Linux
Summary
by MITRE • 09/04/2026
In the Linux kernel, the following vulnerability has been resolved:
arm64: dts: renesas: ironhide: Describe inline ECC carveouts
The DBSC5 DRAM controller protects DRAM content using inline ECC. The inline ECC utilizes areas of DRAM for its operation, which are in the DRAM address range, but must not be accessed or modified. Describe the inline ECC carveout areas used by the DBSC5 controller on this hardware as reserved-memory, which must not be accessed. Include DRAM areas which are unprotected by ECC as well, those are parts of the DRAM which directly precede the ECC carveout.
In case of high DRAM utilization, unless the inline ECC carveouts are properly reserved, Linux may use and corrupt the memory used by the DBSC5 DRAM controller for inline ECC, which would lead to the system becoming unstable.
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Analysis
by VulDB Data Team • 09/04/2026
The vulnerability described involves a hardware-software interface misconfiguration in the ARM64 architecture specifically affecting Renesas Ironhide platform devices equipped with the DBSC5 dynamic random-access memory controller. This controller implements error correction code mechanisms known as inline ECC, which are essential for maintaining data integrity by detecting and correcting single-bit errors and detecting multi-bit errors within DRAM modules. The operational mechanism of this hardware feature requires dedicating specific regions of physical DRAM to store parity or checksum information necessary for the ECC calculations. These reserved memory areas reside within the overall DRAM address space but are strictly managed by the hardware controller and must remain inaccessible to general-purpose software operations, including operating system kernel processes and user-space applications.
The root cause of this vulnerability lies in the absence of proper device tree configuration that explicitly defines these critical memory regions as reserved. Without explicit description of inline ECC carveouts within the device tree source files for the Renesas Ironhide hardware, the Linux kernel's memory management subsystem remains unaware of these protected zones. Consequently, during normal system operation and particularly under conditions of high DRAM utilization where memory allocation pressure is significant, the kernel may allocate pages from these unprotected areas to satisfy requests from various drivers or applications. This results in software writing data into memory regions that are actively being used by the DBSC5 controller for error correction purposes.
The operational impact of this flaw is severe and manifests as system instability rather than a traditional security breach involving privilege escalation or remote code execution. When user-space or kernel-space processes overwrite ECC metadata, the integrity checks performed by the hardware become invalid. This corruption leads to undetected data errors in other parts of memory that rely on the compromised ECC structures for protection. The immediate consequence is system instability characterized by random crashes, kernel panics, silent data corruption, and unpredictable behavior as the hardware attempts to operate with corrupted correction information. While this does not directly allow an attacker to compromise confidentiality or integrity through malicious exploitation in the conventional sense, it creates a reliability hazard that can be triggered by normal workload patterns, effectively denying service due to system crashes.
From a vulnerability classification perspective, this issue aligns with CWE-401, which describes missing release of memory after effective lifetime leading to resource exhaustion or corruption, although more accurately it reflects CWE-756: Missing Custom Error Handling Mechanism in the context of hardware-software contract violation and CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization. In terms of MITRE ATT&CK mapping, this scenario relates to techniques involving resource manipulation that could lead to denial of service, specifically falling under T1499: Endpoint Denial of Service if the instability is exploited or triggered maliciously, though it primarily represents a configuration error rather than an exploitable code flaw.
To mitigate this vulnerability and restore system stability, it is imperative to update the device tree source files for affected Renesas Ironhide platforms. The fix involves adding reserved-memory nodes that explicitly define the physical addresses and sizes of both the inline ECC carveout areas and any adjacent DRAM regions that are unprotected by ECC but precede these carveouts in memory layout. By marking these regions as reserved, the Linux kernel's memory allocator will exclude them from general allocation pools, ensuring they remain untouched during runtime operations. This configuration ensures a clear boundary between hardware-managed error correction structures and software-accessible memory, thereby preserving data integrity and preventing system instability caused by ECC metadata corruption.