Bug 2525477 (CVE-2026-80702) - CVE-2026-80702 kernel: drm/vmwgfx: fix guest_memory_dirty bitfield clobbered as size
Summary: CVE-2026-80702 kernel: drm/vmwgfx: fix guest_memory_dirty bitfield clobbered ...
Keywords:
Status: NEW
Alias: CVE-2026-80702
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-28 07:47 UTC by OSIDB Bzimport
Modified: 2026-09-01 08:18 UTC (History)
2 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-08-28 07:47:00 UTC
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.


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