CVE-2023-53991

/// Technical description

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

drm/msm/dpu: Disallow unallocated resources to be returned

In the event that the topology requests resources that have not been

created by the system (because they are typically not represented in

dpu_mdss_cfg ^1), the resource(s) in global_state (in this case DSC

blocks, until their allocation/assignment is being sanity-checked in

"drm/msm/dpu: Reject topologies for which no DSC blocks are available")

remain NULL but will still be returned out of

dpu_rm_get_assigned_resources, where the caller expects to get an array

containing num_blks valid pointers (but instead gets these NULLs).

To prevent this from happening, where null-pointer dereferences

typically result in a hard-to-debug platform lockup, num_blks shouldn't

increase past NULL blocks and will print an error and break instead.

After all, max_blks represents the static size of the maximum number of

blocks whereas the actual amount varies per platform.

^1: wh

/// 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