CVE-2024-35833

What it actually does

The vulnerability is a memory leak in the fsl-qdma DMA engine driver where dma_alloc_coherent() allocations for queue command DMA are never released in the remove function or in fsl_qdma_probe() error paths.

Why it matters to the business

Long-running systems using Freescale QDMA hardware may suffer gradual memory exhaustion, leading to degraded performance, instability, or denial of service in embedded, networking, or storage environments; the issue is widespread in the Linux kernel ecosystem but has low exploitability.

How an attack unfolds

An attacker with local access could repeatedly trigger driver probe failures or module load/unload cycles to accumulate unreleased DMA coherent memory until system resources are depleted; no public exploits, ransomware usage, or named threat actor campaigns are associated with this flaw.

How to fix it

Update the Linux kernel to a version containing commit 1c75fe450b5200c78f4a102a0eb8e15d8f1ccda8; replace dma_alloc_coherent() calls with the managed dma_alloc_coherent() variant in the fsl-qdma driver.

How to confirm the fix worked

Confirm the presence of commit 1c75fe450b5200c78f4a102a0eb8e15d8f1ccda8 in the kernel tree; review driver code to verify managed allocation is used and test probe/remove paths for proper resource release.

Typical attack path

1. Gain local access to a system using the fsl-qdma driver
2. Cause repeated probe errors or module reloads to trigger allocations
3. Observe progressive memory depletion until the system becomes unstable

How to detect it

Review kernel logs and memory statistics for repeated DMA allocation patterns tied to the qdma driver without corresponding frees; no specific post-exploitation artifacts are known.

What your security team should do

• Prioritize kernel updates on all systems using Freescale QDMA hardware
• Monitor memory usage trends on affected devices for unexpected growth
• Test driver stability after applying the fix before broad deployment