CVE-2023-54217: 
Linux Ubuntu vulnerability analysis and mitigation

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

Revert "drm/msm: Add missing check and destroy for alloc_ordered_workqueue"

This reverts commit 643b7d0869cc7f1f7a5ac7ca6bd25d88f54e31d0.

A recent patch that tried to fix up the msm_drm_init() paths with respect to the workqueue but only ended up making things worse:

First, the newly added calls to msm_drm_uninit() on early errors would trigger NULL-pointer dereferences, for example, as the kms pointer would not have been initialised. (Note that these paths were also modified by a second broken error handling patch which in effect cancelled out this part when merged.)

Second, the newly added allocation sanity check would still leak the previously allocated drm device.

Instead of trying to salvage what was badly broken (and clearly not tested), let's revert the bad commit so that clean and backportable fixes can be added in its place.

Patchwork: https://patchwork.freedesktop.org/patch/525107/