CVE-2024-49920

What it actually does

Missing null checks on stream_enc and dc->bw_vbios pointers after initial validation allow subsequent dereferences in drm/amd/display code paths, creating forward-null conditions reported by static analysis.

Why it matters to the business

Kernel crashes or unexpected behavior on AMD display hardware can interrupt graphics workloads and require reboots, though the flaw has low public exploitability and limited downstream package reach.

How an attack unfolds

An attacker with local access crafts display configuration or driver state that leaves the checked pointers null, then triggers the later code paths that dereference them without re-validation, leading to a kernel fault.

How to fix it

Update the Linux kernel to commit 26787fb6c2b2ee0d1a7e1574b36f4711ae40fe27 or later; for Rocky Linux 8 openwsman packages upgrade to 2.6.5-7.el8_3 or newer equivalent.

How to confirm the fix worked

Confirm the presence of the null-pointer guard additions around stream_enc and dc->bw_vbios in the patched drm/amd/display source; verify no remaining Coverity FORWARD_NULL warnings for these symbols in the updated build.

Typical attack path

1. Obtain local user or process execution context on an affected Linux system with AMD display hardware
2. Trigger display stream or bandwidth allocation code that performs the initial null checks but leaves pointers unset
3. Force execution through subsequent uses of the unchecked pointers inside the same function
4. Cause kernel oops or denial of service from the resulting null dereference

How to detect it

Search kernel logs and dmesg for oops or panic entries referencing drm/amd/display functions that use stream_enc or bw_vbios; correlate with display reconfiguration events.

What your security team should do

• Prioritize kernel package updates on systems with AMD GPUs within standard maintenance windows given low EPSS and absence from KEV
• Monitor vendor advisories for backported fixes in distribution kernels
• Review graphics driver logs for unexpected null-related faults as a general hardening step