CVE-2024-27026

What it actually does

The vmxnet3 driver incorrectly calculates packet length for non-dataring XDP frames by using rcd->len instead of rbi->len, resulting in insufficient tailroom reservation and triggering XDP frame validation warnings or potential memory corruption during redirect processing.

Why it matters to the business

Virtual machines using the vmxnet3 paravirtualized NIC may experience kernel warnings, degraded network performance, or crashes under XDP workloads, affecting availability in cloud and virtualized environments with high packet processing demands.

How an attack unfolds

An attacker sends crafted network traffic to a vmxnet3 interface configured for XDP, causing the driver to process frames without adequate tailroom; this leads to xdp_update_frame_from_buff warnings during vmxnet3_run_xdp and potential memory safety violations in napi poll paths, which could be leveraged by espionage or financially motivated actors for denial of service or further kernel exploitation.

How to fix it

Update the Linux kernel to the fixed commit aba8659caf88017507419feea06069f529329ea6 or later stable releases containing the vmxnet3 tailroom fix; rebuild and deploy the patched kernel across affected systems.

How to confirm the fix worked

Confirm the running kernel contains commit aba8659caf88017507419feea06069f529329ea6; test XDP workloads on vmxnet3 interfaces and verify absence of xdp_warn messages in dmesg related to missing reserved tailroom.

Typical attack path

1. Identify target systems running vulnerable vmxnet3 driver with XDP enabled
2. Send specially crafted packets that trigger vmxnet3_process_xdp and vmxnet3_rq_rx_complete paths
3. Trigger xdp_do_redirect with insufficient tailroom to produce XDP_WARN and potential corruption
4. Escalate from warning to memory corruption or crash for denial of service or code execution

How to detect it

Search kernel logs for xdp_warn entries mentioning missing reserved tailroom, xdp_update_frame_from_buff, and vmxnet3_run_xdp stack traces; correlate with vmxnet3_poll_rx_only activity and unusual XDP redirect events in high-volume network environments.

What your security team should do

• Prioritize kernel updates for all systems using vmxnet3 in production within the next maintenance window
• Monitor EPSS trend and threat actor reports for any increase in in-the-wild exploitation
• Temporarily disable XDP on vmxnet3 interfaces if patching is delayed and workloads permit
• Review downstream package ecosystems for dependent distributions and apply vendor backports promptly