CVE-2024-27056

What it actually does

The flaw is a missing allocation check in the iwlwifi mvm resume path: if no packets have ever been sent on TID 0, the offloading TX queue does not exist, yet the code still attempts to synchronize the firmware-updated write pointer, resulting in a NULL dereference or invalid memory access.

Why it matters to the business

Laptops and servers using Intel Wi-Fi hardware can crash on resume from suspend, causing unplanned downtime, lost work, and repeated reboot cycles; the issue is widespread because the affected driver ships in the mainline kernel used by virtually all Linux distributions.

How an attack unfolds

An attacker triggers a suspend/resume cycle on a system where the iwlwifi driver has never transmitted on TID 0; at resume the driver dereferences an unallocated queue structure and panics, achieving a local denial of service without needing special privileges beyond the ability to initiate suspend.

How to fix it

Update the Linux kernel to a version containing commit 4903303f25f48b5a1e34e6324c7fae9ccd6b959a (or the equivalent stable backport) which guarantees the offloading TID queue is allocated before suspend; rebuild and reboot with the fixed kernel.

How to confirm the fix worked

Confirm the running kernel tree contains commit 4903303f25f48b5a1e34e6324c7fae9ccd6b959a via git log or /proc/version signature; test by suspending a system that has sent no TID-0 traffic and verifying successful resume without oops.

Typical attack path

1. Gain local access or user context on a Linux system with iwlwifi hardware
2. Ensure no traffic has been sent on TID 0 (common on idle or freshly booted systems)
3. Initiate system suspend
4. Resume the system
5. Trigger kernel panic in the resume code path

How to detect it

Search kernel logs and crash dumps for oops/panic strings containing iwlwifi, mvm, offloading TID, or write pointer synchronization failures during resume paths; correlate with timestamps of suspend/resume events.

What your security team should do

• Immediately schedule kernel updates containing the referenced commit on all affected distributions
• Add kernel panic and iwlwifi resume oops events to monitoring dashboards
• Prioritize patching of mobile and laptop fleets where suspend/resume cycles are frequent