Description
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: guard dc_sink dereferences in MST mode validation
dm_dp_mst_is_port_support_mode() reads aconnector->dc_sink->dsc_caps... for the DSC branch-throughput check, and get_conv_frl_bw()'s HDMI-PCON FRL-bandwidth path reads aconnector->dc_sink->edid_caps.max_frl_rate, both without a NULL check. dc_sink is cleared asynchronously on MST unplug, and both functions run from paths that the driver's own comments document as racing that teardown: the connector probe worker's ->mode_valid callback and a compositor's atomic check, neither of which holds the MST manager lock that the teardown path uses. The former does have an existing dsc_aux NULL check, but dsc_aux isn't reliably cleared in every path that clears dc_sink, so it doesn't cover this.
Fail the port-support check and skip the FRL conversion path when the sink is already gone.
(cherry picked from commit 7c3db8da4e039698ae198c870712428644e965c7)
Metrics
No CVSS score has been published yet.
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
No affected versions have been published.
Timeline
- Published
- Oct 18, 2026
- Last modified
- Oct 19, 2026
- NVD status
- Received