CVE-2026-80702drm/vmwgfx: fix guest_memory_dirty bitfield clobbered as size

Official description

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 packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/21bbe38faee4a195d33a93e3908e307807f7745d
• https://git.kernel.org/stable/c/9d6cbb76fe9cd760351f6b0b20f1bf788eab8fa6
• https://git.kernel.org/stable/c/282f261cb035e5f01a486f76d356b7e9dbfba73f
• https://git.kernel.org/stable/c/3b2bb16a5b622867140d69925db411ac8ecb3b2b
• https://git.kernel.org/stable/c/83195b778f2d109a3a4f3ffaba4dce7e4cdb58aa