CVE-2026-23182: Linux Kernel Memory Leak Vulnerability

CVE-2026-23182 Overview

A memory leak vulnerability has been identified in the Linux kernel's SPI Tegra driver. Specifically, the tegra_slink_probe() function in the SPI subsystem fails to properly clean up allocated resources when platform_get_irq() returns an error. Instead of jumping to a cleanup label to free previously allocated memory, the function directly returns with an error code, leaving memory unreleased and leading to a resource leak condition.

Critical Impact

Systems using the Tegra SPI SLINK driver may experience gradual memory exhaustion through repeated probe failures, potentially leading to system instability or denial of service conditions on affected embedded Linux systems.

Affected Products

• Linux kernel with SPI Tegra SLINK driver enabled
• Systems utilizing NVIDIA Tegra SoC platforms
• Embedded Linux distributions with Tegra support

Discovery Timeline

• 2026-02-14 - CVE CVE-2026-23182 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-23182

Vulnerability Analysis

This vulnerability is classified as a Memory Leak within the Linux kernel's SPI (Serial Peripheral Interface) Tegra SLINK driver subsystem. The flaw occurs during the device probe initialization sequence where proper error handling cleanup paths were not implemented.

When a Tegra-based system initializes the SPI SLINK controller, the tegra_slink_probe() function allocates various resources including memory structures for the SPI master device. During this initialization, if the platform_get_irq() function fails to obtain an IRQ resource, the error handling path directly returns from the function without releasing previously allocated memory resources.

This improper resource management creates a memory leak condition. While a single occurrence may have minimal impact, repeated driver probe attempts (which can occur during device hotplug events, driver reload operations, or system boot with faulty hardware configurations) can gradually exhaust kernel memory resources.

Root Cause

The root cause of this vulnerability lies in incomplete error handling logic within the tegra_slink_probe() function. The function allocates memory early in its execution flow but lacks a proper cleanup goto label for the platform_get_irq() failure case. Instead of following the established kernel coding pattern of using goto labels for unified cleanup, the code path directly returns the error, bypassing resource deallocation routines.

The fix replaces the direct return statement with a goto to an appropriate cleanup label, ensuring that all previously allocated resources are properly freed before the function exits with an error.

Attack Vector

The attack vector for this vulnerability is limited as it requires local access or the ability to trigger repeated probe failures on the SPI subsystem. Exploitation scenarios include:

Repeated attempts to load/unload the Tegra SLINK driver module can trigger the memory leak. On systems where hardware initialization repeatedly fails due to misconfiguration or hardware faults, the leak compounds over time. An attacker with local access could potentially craft scenarios that cause repeated probe failures to gradually exhaust system memory.

The practical exploitability depends heavily on system configuration and requires either local access or the ability to influence driver loading behavior. The vulnerability is most impactful on resource-constrained embedded systems using Tegra SoCs where memory is limited.

Detection Methods for CVE-2026-23182

Indicators of Compromise

• Unexplained gradual increase in kernel memory usage (/proc/meminfo showing decreasing available memory)
• SPI SLINK driver probe failure messages in kernel logs (dmesg | grep slink)
• System memory pressure events or OOM (Out of Memory) killer activation on Tegra-based systems
• Repeated driver initialization failures visible in system logs

Detection Strategies

• Monitor kernel log output for repeated tegra_slink_probe failure messages using log aggregation tools
• Implement kernel memory tracking using tools like kmemleak to detect memory leaks in the SPI subsystem
• Use SentinelOne's kernel module monitoring to track driver loading patterns and memory allocation anomalies
• Deploy automated kernel log analysis to correlate probe failures with memory consumption trends

Monitoring Recommendations

• Enable kernel memory leak detection debugging (CONFIG_DEBUG_KMEMLEAK) on development and test systems
• Configure alerts for sustained memory growth patterns on production Tegra-based devices
• Monitor /sys/kernel/slab/ statistics for SPI-related memory allocations
• Implement baseline memory profiling for embedded systems to detect deviation from normal resource usage

How to Mitigate CVE-2026-23182

Immediate Actions Required

• Apply the kernel patches from the stable branches to address the memory leak
• Review current kernel version and determine if affected driver is in use on Tegra platforms
• Monitor affected systems for memory consumption anomalies pending patch deployment
• Consider disabling the Tegra SLINK driver if not required for system operation

Patch Information

The Linux kernel maintainers have released patches to multiple stable branches that fix this memory leak. The fix involves replacing the direct error return with a goto statement to ensure proper resource cleanup. The following kernel commits address this vulnerability:

• Kernel Git Commit 075415a
• Kernel Git Commit 126a09f
• Kernel Git Commit 327b71
• Kernel Git Commit 41d9a6
• Kernel Git Commit 6a04dc
• Kernel Git Commit b8eec12

Apply the appropriate patch based on your kernel version by updating to a patched kernel release or cherry-picking the relevant commit.

Workarounds

• Blacklist the spi-tegra-slink module on systems where it is not required (echo "blacklist spi-tegra-slink" >> /etc/modprobe.d/blacklist.conf)
• Implement system monitoring to restart services or trigger reboots if memory exhaustion thresholds are reached
• Use cgroup memory limits to contain potential memory leak impact on affected systems
• Schedule regular system reboots as a temporary measure to reclaim leaked memory on critical embedded deployments

# Configuration example
# Check if Tegra SLINK driver is loaded
lsmod | grep spi_tegra

# Monitor kernel memory for leaks
cat /proc/meminfo | grep -E "MemFree|MemAvailable|Slab"

# Blacklist the module if not required
echo "blacklist spi-tegra-slink" | sudo tee /etc/modprobe.d/tegra-slink-blacklist.conf

# Verify kernel version and check for patched releases
uname -r