CVE-2026-53022: Linux Kernel Buffer Overflow Vulnerability

CVE-2026-53022 Overview

CVE-2026-53022 is a Linux kernel vulnerability in the dell-wmi-sysman platform driver. The populate_enum_data() function aggregates firmware-provided value-modifier and possible-value strings into fixed 512-byte struct members. While the driver bounds each individual source string, it then appends every string and separator using raw strcat() without checking the remaining destination space. Maliciously crafted or oversized firmware enumeration packages can overflow the destination buffers. The upstream fix replaces the aggregation loops with a bounded append helper and rejects enumeration packages whose combined strings do not fit.

Critical Impact
Unbounded strcat() operations on firmware-supplied strings can corrupt adjacent kernel memory in the dell-wmi-sysman driver, leading to kernel memory corruption on affected Dell systems.

Affected Products

Linux kernel platform/x86: dell-wmi-sysman driver
Dell systems exposing BIOS attributes through the WMI sysman interface
Stable kernel branches referenced in the upstream fix commits

Discovery Timeline

2026-06-24 - CVE-2026-53022 published to NVD
2026-06-24 - Last updated in NVD database

Technical Details for CVE-2026-53022

Vulnerability Analysis

The flaw resides in populate_enum_data() within the dell-wmi-sysman platform driver. The driver reads enumeration attribute data exposed by system firmware via Windows Management Instrumentation (WMI) and stores aggregated value-modifier and possible-value strings into fixed 512-byte fields inside its attribute structures. Each individual source string is length-checked before use. However, the aggregation step concatenates the strings together with strcat() calls and separator characters without ever verifying how much space remains in the destination buffer.

When firmware presents enumeration packages whose combined strings exceed 512 bytes, the unchecked strcat() writes past the end of the struct member. This is an out-of-bounds write in kernel space, corrupting adjacent fields or kernel heap memory. The patched code replaces the loop with a bounded append helper and rejects packages that cannot fit, eliminating the overflow condition.

Root Cause

The root cause is missing remaining-space validation during string aggregation. Bounding each input string individually is insufficient when many strings and separators are concatenated into a fixed-size destination. The use of strcat() with no length tracking is the canonical pattern that produces this class of buffer overflow.

Attack Vector

Exploitation requires the firmware-supplied WMI enumeration data to contain combined strings exceeding the destination buffer size. Triggering the overflow depends on the platform firmware or any path that can influence the WMI enumeration payload consumed by the kernel driver during initialization or attribute parsing.

No verified public proof-of-concept code is available. Refer to the upstream patch series for the exact source-level change.

Detection Methods for CVE-2026-53022

Indicators of Compromise

Kernel oops, panic, or KASAN reports referencing populate_enum_data, dell-wmi-sysman, or strcat in the call stack
Unexpected slab-out-of-bounds or memory corruption warnings tied to the dell-wmi-sysman module load
Failures or anomalies reading sysfs entries under /sys/class/firmware-attributes/dell-wmi-sysman/

Detection Strategies

Inventory Linux endpoints with the dell-wmi-sysman module loaded and compare kernel versions against the patched stable releases
Enable KASAN on test or canary systems to surface out-of-bounds writes originating in the driver
Monitor dmesg and journald for kernel warnings emitted during boot when WMI attributes are parsed

Monitoring Recommendations

Centralize kernel logs from Dell client and server fleets and alert on driver-related oops or panic signatures
Track kernel package versions across the fleet and flag hosts running unpatched stable branches
Audit firmware update history on Dell systems to correlate attribute table changes with kernel events

How to Mitigate CVE-2026-53022

Immediate Actions Required

Update the Linux kernel to a stable release containing the upstream fix referenced in the commits below
On systems that cannot be patched immediately, unload or blacklist the dell-wmi-sysman module if its functionality is not required
Restrict local administrative access on affected Dell systems while patching is in progress

Patch Information

The vulnerability is resolved by replacing the unbounded strcat() aggregation in populate_enum_data() with a bounded append helper that rejects oversized enumeration packages. The fix is distributed across multiple stable branches: Kernel Git Commit 90b118d, Kernel Git Commit 3c34471, Kernel Git Commit 5a04f9a, Kernel Git Commit 75c738d, Kernel Git Commit 7b3dc1f, Kernel Git Commit ba0843c, and Kernel Git Commit c5683ca.

Workarounds

Blacklist the driver by adding blacklist dell-wmi-sysman to a file under /etc/modprobe.d/ and rebuilding the initramfs
Avoid enabling firmware attribute management tooling that exercises the WMI sysman interface until patches are applied
Apply available Dell firmware updates to reduce exposure to anomalous enumeration payloads

bash

# Blacklist the affected driver until the kernel is patched
echo 'blacklist dell-wmi-sysman' | sudo tee /etc/modprobe.d/dell-wmi-sysman.conf
sudo update-initramfs -u
sudo reboot

# Confirm the module is not loaded after reboot
lsmod | grep dell_wmi_sysman