In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: validate external BO copy bounds for both stride paths
vmw_external_bo_copy() trusts caller-supplied offsets, strides, and
heights and operates on imported dma-buf vmaps:
- The equal-stride memcpy() bound was clamped after subtracting the
offsets from dst_size and src_size; an offset larger than the BO
size wraps the unsigned subtraction to a huge value and the
resulting memcpy() runs off the end of the vmap. dst_stride *
height is also a u32 multiplication that can overflow.
- The non-equal-stride row-by-row path had no bound at all. The
loop touches bytes through offset + (height - 1) * stride +
width_in_bytes, with only a WARN_ON(dst_stride < width_in_bytes),
and could likewise step past the end of either mapping.
The offsets and strides are derived from STDU/SOU plane state, so a
configured CRTC submitting a crafted atomic commit on an imported
framebuffer can reach this path.
Validate the exact row-copy endpoint against each BO's size up front
using check_mul_overflow() and check_add_overflow(). Use the bulk
memcpy() path only when width_in_bytes covers the whole stride;
otherwise copy one row at a time so partial-row updates near the bottom
of a framebuffer remain valid. Also reject zero strides and stride <
width_in_bytes, both of which the row-by-row path cannot represent
safely.
drm/vmwgfx: validate external BO copy bounds for both stride paths
vmw_external_bo_copy() trusts caller-supplied offsets, strides, and
heights and operates on imported dma-buf vmaps:
- The equal-stride memcpy() bound was clamped after subtracting the
offsets from dst_size and src_size; an offset larger than the BO
size wraps the unsigned subtraction to a huge value and the
resulting memcpy() runs off the end of the vmap. dst_stride *
height is also a u32 multiplication that can overflow.
- The non-equal-stride row-by-row path had no bound at all. The
loop touches bytes through offset + (height - 1) * stride +
width_in_bytes, with only a WARN_ON(dst_stride < width_in_bytes),
and could likewise step past the end of either mapping.
The offsets and strides are derived from STDU/SOU plane state, so a
configured CRTC submitting a crafted atomic commit on an imported
framebuffer can reach this path.
Validate the exact row-copy endpoint against each BO's size up front
using check_mul_overflow() and check_add_overflow(). Use the bulk
memcpy() path only when width_in_bytes covers the whole stride;
otherwise copy one row at a time so partial-row updates near the bottom
of a framebuffer remain valid. Also reject zero strides and stride <
width_in_bytes, both of which the row-by-row path cannot represent
safely.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 28 Aug 2026 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-119 CWE-680 |
Fri, 28 Aug 2026 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: validate external BO copy bounds for both stride paths vmw_external_bo_copy() trusts caller-supplied offsets, strides, and heights and operates on imported dma-buf vmaps: - The equal-stride memcpy() bound was clamped after subtracting the offsets from dst_size and src_size; an offset larger than the BO size wraps the unsigned subtraction to a huge value and the resulting memcpy() runs off the end of the vmap. dst_stride * height is also a u32 multiplication that can overflow. - The non-equal-stride row-by-row path had no bound at all. The loop touches bytes through offset + (height - 1) * stride + width_in_bytes, with only a WARN_ON(dst_stride < width_in_bytes), and could likewise step past the end of either mapping. The offsets and strides are derived from STDU/SOU plane state, so a configured CRTC submitting a crafted atomic commit on an imported framebuffer can reach this path. Validate the exact row-copy endpoint against each BO's size up front using check_mul_overflow() and check_add_overflow(). Use the bulk memcpy() path only when width_in_bytes covers the whole stride; otherwise copy one row at a time so partial-row updates near the bottom of a framebuffer remain valid. Also reject zero strides and stride < width_in_bytes, both of which the row-by-row path cannot represent safely. | |
| Title | drm/vmwgfx: validate external BO copy bounds for both stride paths | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-28T06:53:04.050Z
Reserved: 2026-08-26T14:34:25.786Z
Link: CVE-2026-80700
No data.
Status : Received
Published: 2026-08-28T08:16:55.517
Modified: 2026-08-28T08:16:55.517
Link: CVE-2026-80700
No data.
OpenCVE Enrichment
Updated: 2026-08-28T11:00:11Z