CVE-2024-27409

What it actually does

Race condition in dw-edma HDMA remote setup where doorbell register can be toggled before linked-list writes complete due to separate memory domains, allowing incomplete DMA descriptor setup.

Why it matters to the business

Potential DMA transfer failures or data corruption on Linux systems using affected dw-edma controllers, increasing operational risk for storage, networking, or device drivers until patched.

How an attack unfolds

An attacker with local access triggers DMA operations in remote HDMA configuration, racing the doorbell toggle against pending linked-list writes to induce incomplete transfers or kernel instability.

How to fix it

Update the Linux kernel to include commit 227ef58a9b0c372efba422e8886a8015a1509eba which adds the required sync read before DMA start in remote HDMA setup.

How to confirm the fix worked

Verify kernel source contains commit 227ef58a9b0c372efba422e8886a8015a1509eba or test DMA channel initialization under load to confirm absence of the race.

Typical attack path

1. Identify system using dw-edma HDMA in remote setup
2. Trigger DMA channel setup via user-space or driver interface
3. Time doorbell register write before full linked-list memory commit
4. Observe resulting transfer errors or system impact

How to detect it

Inspect kernel logs for DMA engine errors or warnings during channel setup on dw-edma devices; no widespread exploitation artifacts reported.

What your security team should do

• Apply the kernel commit or newer stable release containing the fix as highest priority
• Monitor for DMA-related kernel warnings on systems using dw-edma controllers
• Review device driver usage of remote HDMA setups for additional hardening