CVE-2023-53991

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/msm/dpu: Disallow unallocated resources to be returned<br /> <br /> In the event that the topology requests resources that have not been<br /> created by the system (because they are typically not represented in<br /> dpu_mdss_cfg ^1), the resource(s) in global_state (in this case DSC<br /> blocks, until their allocation/assignment is being sanity-checked in<br /> "drm/msm/dpu: Reject topologies for which no DSC blocks are available")<br /> remain NULL but will still be returned out of<br /> dpu_rm_get_assigned_resources, where the caller expects to get an array<br /> containing num_blks valid pointers (but instead gets these NULLs).<br /> <br /> To prevent this from happening, where null-pointer dereferences<br /> typically result in a hard-to-debug platform lockup, num_blks shouldn&amp;#39;t<br /> increase past NULL blocks and will print an error and break instead.<br /> After all, max_blks represents the static size of the maximum number of<br /> blocks whereas the actual amount varies per platform.<br /> <br /> ^1: which can happen after a git rebase ended up moving additions to<br /> _dpu_cfg to a different struct which has the same patch context.<br /> <br /> Patchwork: https://patchwork.freedesktop.org/patch/517636/