drm/amd/display: guard dc_sink dereferences in MST mode validation
Summary
| CVE | CVE-2026-98786 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-18 16:17:32 UTC |
| Updated | 2026-11-10 19:22:26 UTC |
| 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) |
Risk And Classification
EPSS: 0.001660000 probability, percentile 0.058830000 (date 2026-11-10)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected f04d275d94e164d24516c32437c988a323018f63 0189f725242087679bc9f1bbf77ad086f56a72c8 git | Not specified |
| CNA | Linux | Linux | affected f04d275d94e164d24516c32437c988a323018f63 5684a6c24c0d7c40ef2c4ccb3e4a64cffe76a791 git | Not specified |
| CNA | Linux | Linux | affected f04d275d94e164d24516c32437c988a323018f63 daa0437fe5e451856aaf8fda602a9fc2105bbd54 git | Not specified |
| CNA | Linux | Linux | affected f04d275d94e164d24516c32437c988a323018f63 217f64f348c90cba62164e7ff38e0ccf78a5ca09 git | Not specified |
| CNA | Linux | Linux | affected 6.0 | Not specified |
| CNA | Linux | Linux | unaffected 6.0 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.117 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.61 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.10 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/217f64f348c90cba62164e7ff38e0ccf78a5ca09 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5684a6c24c0d7c40ef2c4ccb3e4a64cffe76a791 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/daa0437fe5e451856aaf8fda602a9fc2105bbd54 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0189f725242087679bc9f1bbf77ad086f56a72c8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.