CVE-2026-23180: Linux Kernel Buffer Overflow Vulnerability

CVE-2026-23180 Overview

CVE-2026-23180 is an Out-of-Bounds Read vulnerability in the Linux kernel's dpaa2-switch driver. The vulnerability exists within the IRQ handler, which extracts if_id from the upper 16 bits of the hardware status register and uses it to index into the ethsw->ports[] array without proper validation. Since if_id can be any 16-bit value (0-65535) but the ports array is only allocated with sw_attr.num_ifs elements, this can lead to an out-of-bounds memory read.

Critical Impact

An attacker capable of manipulating hardware status register values could trigger out-of-bounds memory access, potentially leading to information disclosure or system instability on affected Linux systems using the dpaa2-switch driver.

Affected Products

• Linux kernel with dpaa2-switch driver enabled
• Systems using NXP Layerscape DPAA2 networking hardware
• Enterprise networking appliances and embedded systems utilizing affected kernel versions

Discovery Timeline

• 2026-02-14 - CVE CVE-2026-23180 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-23180

Vulnerability Analysis

The vulnerability resides in the dpaa2-switch driver's interrupt request (IRQ) handler implementation. When processing hardware interrupts, the handler reads the status register and extracts the interface ID (if_id) from the upper 16 bits. This value is then directly used as an index into the ethsw->ports[] array without verifying whether it falls within the valid range of allocated elements.

The ports array is dynamically allocated during driver initialization based on sw_attr.num_ifs, which represents the actual number of interfaces present on the hardware. However, the if_id extracted from the hardware status register is a 16-bit unsigned integer, meaning it can theoretically contain any value from 0 to 65535. When an if_id value exceeds the bounds of the allocated array, the kernel attempts to read memory beyond the array's boundaries.

This type of bounds-checking failure can result in reading sensitive kernel memory contents, triggering kernel panics due to accessing unmapped memory regions, or causing unpredictable system behavior. The fix adds explicit validation to ensure if_id is within bounds before array access, consistent with similar checks already present in dpaa2_switch_rx().

Root Cause

The root cause is a missing input validation check in the IRQ handler path. While the dpaa2_switch_rx() function already contained bounds validation for the if_id parameter, the IRQ handler code path was missing this critical check. The hardware status register value was trusted implicitly without considering that malformed or malicious hardware responses could contain out-of-range values.

Attack Vector

The attack vector involves triggering interrupt conditions where the hardware status register contains a crafted if_id value exceeding the legitimate array bounds. This could occur through:

The vulnerability manifests when the IRQ handler processes interrupt events. An attacker with physical access to the hardware or the ability to manipulate hardware state could potentially craft malicious status register values. Additionally, firmware bugs or hardware faults could inadvertently trigger this condition. The fix ensures that regardless of the hardware-provided value, the kernel performs bounds validation before accessing the array.

For detailed technical information about the fix implementation, see the Kernel.org Commit.

Detection Methods for CVE-2026-23180

Indicators of Compromise

• Unexpected kernel panics or oops messages referencing dpaa2-switch driver code paths
• Memory access violations logged in kernel ring buffer (dmesg) related to network driver operations
• System instability when processing network traffic on DPAA2 switch interfaces

Detection Strategies

• Monitor kernel logs for out-of-bounds access warnings or KASAN (Kernel Address Sanitizer) reports related to the dpaa2-switch module
• Deploy kernel instrumentation to track array bounds violations in network driver code paths
• Implement runtime integrity checking for kernel memory regions associated with network drivers

Monitoring Recommendations

• Enable kernel debugging features such as KASAN and UBSAN in development and testing environments to detect bounds violations
• Configure centralized logging for kernel messages across all systems running affected kernel versions
• Implement network anomaly detection to identify unusual interrupt patterns on DPAA2 hardware interfaces

How to Mitigate CVE-2026-23180

Immediate Actions Required

• Identify all systems running Linux kernels with the dpaa2-switch driver enabled
• Apply kernel updates containing the bounds check fix from upstream stable branches
• Prioritize patching for systems in network-facing or security-sensitive roles
• Review system logs for any evidence of exploitation attempts prior to patching

Patch Information

Multiple kernel stable branches have received patches addressing this vulnerability. The fix adds a bounds check for if_id before accessing the ethsw->ports[] array in the IRQ handler, consistent with existing validation in dpaa2_switch_rx().

Patch commits are available from the following kernel.org stable branches:

• Commit 1b381a638e18
• Commit 2447edc36780
• Commit 31a7a0bbeb00
• Commit 34b56c16efd6
• Commit 77611cab5bdf
• Commit f89e33c9c37f

Workarounds

• If immediate patching is not feasible, consider disabling the dpaa2-switch driver module on non-essential systems
• Implement network segmentation to limit exposure of systems using DPAA2 hardware
• Restrict physical access to affected networking hardware to prevent hardware-based manipulation

# Check if dpaa2-switch module is loaded
lsmod | grep dpaa2_switch

# Temporarily disable the module (requires network reconfiguration)
modprobe -r dpaa2_switch

# Blacklist module to prevent automatic loading (temporary workaround only)
echo "blacklist dpaa2_switch" >> /etc/modprobe.d/blacklist-dpaa2.conf