CVE-2023-52706

What it actually does

Inverted conditional logic in gpio_sim_remove_hogs prevents deallocation of GPIO hog structures, resulting in a persistent memory leak each time the removal path executes.

Why it matters to the business

Long-running systems using the GPIO simulation driver may experience gradual kernel memory exhaustion, leading to degraded performance or eventual instability, though the narrow scope of the simulation module limits widespread operational disruption.

How an attack unfolds

An attacker with local kernel access loads the gpio-sim module, configures hogs, and repeatedly exercises the removal path to accumulate unfreed memory; no named threat actors or ransomware campaigns are associated with this issue.

How to fix it

Update the Linux kernel to a version containing commit 854e1ecff266033d3149666d3c5b8b0e174b4210 or later; rebuild and deploy the fixed kernel across affected systems.

How to confirm the fix worked

Verify the presence of the corrected gpio_sim_remove_hogs logic in the running kernel source or confirm the git commit hash is included in the deployed kernel build.

Typical attack path

1. Load the gpio-sim kernel module
2. Configure one or more GPIO hog structures
3. Trigger gpio_sim_remove_hogs via module unload or device removal
4. Repeat the cycle to accumulate unfreed allocations

How to detect it

Inspect kernel logs and memory accounting for repeated gpio-sim allocations that are never freed; correlate with module load/unload events in audit or dmesg records.

What your security team should do

• Prioritize kernel updates containing the referenced commit for all systems using gpio-sim
• Review kernel configurations to disable gpio-sim when simulation functionality is unnecessary
• Incorporate memory-leak regression tests for GPIO subsystems in CI pipelines