CVE-2024-57922

What it actually does

Missing zero-check on granularity parameter in dcn_bw_ceil2 and dcn_bw_floor2 wrapper functions allows divide-by-zero and assertion failures during display bandwidth calculations.

Why it matters to the business

Kernel instability or crashes on AMD display hardware can interrupt graphical workloads, reduce system availability, and require emergency reboots; low EPSS and no KEV status indicate limited immediate operational risk but still warrant patching before widespread deployment.

How an attack unfolds

An attacker supplies display configuration data that causes the dml helpers to be invoked with granularity equal to zero, triggering the unchecked division path inside the dcn_bw functions; listed threat actors have targeted similar Linux kernel resource and bounds issues but no public exploitation of this specific flaw is recorded.

How to fix it

Apply the upstream fix (commit 8a9315e6f7b2d94c65a1ba476481deddb20fc3ae) or later; for listed Red Hat packages upgrade squid and related debug/sysvinit packages to 7:3.3.8-26.el7_2.3 or newer; rebuild and reboot affected kernels after applying the patch.

How to confirm the fix worked

Confirm kernel source contains the granularity != 0 guard before calling dcn_bw_ceil2/dcn_bw_floor2; verify package versions match the fixed releases; run display mode enumeration and bandwidth tests to ensure no assertions or division errors occur.

Typical attack path

1. Identify AMD GPU system running vulnerable kernel
2. Craft or trigger display mode or bandwidth calculation that passes granularity=0
3. Invoke dcn_bw_ceil2 or dcn_bw_floor2 without the missing guard
4. Cause divide-by-zero or assertion, leading to kernel panic or denial of service

How to detect it

Review kernel logs for divide-by-zero or assertion messages originating from dml or dcn_bw functions; correlate with display mode changes or AMD GPU initialization events; no specific post-exploitation artifacts are known.

What your security team should do

• Prioritize kernel updates on all AMD GPU hosts within normal change windows given stable low EPSS
• Add the fixed commit hash to internal patch review and SBOM tracking
• Monitor for future backports to distribution kernels and verify post-upgrade stability