CVE-2024-27040

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Add 'replay' NULL check in 'edp_set_replay_allow_active()'

In the first if statement, we're checking if 'replay' is NULL. But in

the second if statement, we're not checking if 'replay' is NULL again

before calling replay->funcs->replay_set_power_opt().

if (replay == NULL && force_static)

return false;

...

if (link->replay_settings.replay_feature_enabled &&

replay->funcs->replay_set_power_opt) {

replay->funcs->replay_set_power_opt(replay, *power_opts, panel_inst);

link->replay_settings.replay_power_opt_active = *power_opts;

}

If 'replay' is NULL, this will cause a null pointer dereference.

Fixes the below found by smatch:

drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_edp_panel_control.c:895 edp_set_replay_allow_active() error: we previously assumed 'replay' could be null (see line 887)

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References