Affected: Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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

drm/vmwgfx: fix guest_memory_dirty bitfield clobbered as size

Two sites in vmwgfx_resource.c assign boolean literals to res->guest_memory_size, which is an unsigned long allocation-size field; the intended target is the adjacent res->guest_memory_dirty bitfield. After the assignments the field holds 0 or 1 instead of the resource's MOB allocation size:

- vmw_resource_release() writes 0 (false), and - vmw_resource_unbind_list() writes 1 (true).

Subsequent revalidation paths read guest_memory_size when computing the dirty page range (vmw_bo_dirty_transfer_to_res()) and the buffer allocation size (vmw_resource_buf_alloc()), producing zero-length walks or wrap-around ranges that read or write past the MOB bitmap. The dirty-tracking intent of the original code (mark the resource as dirtied since the last sync) is also lost, since guest_memory_dirty is never updated.

Rename both assignments to guest_memory_dirty.

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

drm/vmwgfx: fix guest_memory_dirty bitfield clobbered as size

Two sites in vmwgfx_resource.c assign boolean literals to res->guest_memory_size, which is an unsigned long allocation-size field; the intended target is the adjacent res->guest_memory_dirty bitfield. After the assignments the field holds 0 or 1 instead of the resource's MOB allocation size:

- vmw_resource_release() writes 0 (false), and - vmw_resource_unbind_list() writes 1 (true).

Subsequent revalidation paths read guest_memory_size when computing the dirty page range (vmw_bo_dirty_transfer_to_res()) and the buffer allocation size (vmw_resource_buf_alloc()), producing zero-length walks or wrap-around ranges that read or write past the MOB bitmap. The dirty-tracking intent of the original code (mark the resource as dirtied since the last sync) is also lost, since guest_memory_dirty is never updated.

Rename both assignments to guest_memory_dirty.

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 154 more

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: fix guest_memory_dirty bitfield clobbered as size Two sites in vmwgfx_resource.c assign boolean literals to res->guest_memory_size, which is an unsigned long allocation-size field; the intended target is the adjacent res->guest_memory_dirty bitfield. After the assignments the field holds 0 or 1 instead of the resource's MOB allocation size: - vmw_resource_release() writes 0 (false), and - vmw_resource_unbind_list() writes 1 (true). Subsequent revalidation paths read guest_memory_size when computing the dirty page range (vmw_bo_dirty_transfer_to_res()) and the buffer allocation size (vmw_resource_buf_alloc()), producing zero-length walks or wrap-around ranges that read or write past the MOB bitmap. The dirty-tracking intent of the original code (mark the resource as dirtied since the last sync) is also lost, since guest_memory_dirty is never updated. Rename both assignments to guest_memory_dirty.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, darunter möglicherweise Speicherbeschädigungen, die Offenlegung oder Manipulation von Daten sowie Denial-of-Service-Zustände.