Bug 2525373 (CVE-2026-80700)
| Summary: | CVE-2026-80700 kernel: drm/vmwgfx: validate external BO copy bounds for both stride paths | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | rhel-process-autobot, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the `drm/vmwgfx` component of the Linux kernel. This vulnerability allows a local attacker to cause memory corruption by providing specially crafted input to the `vmw_external_bo_copy()` function. The function, which handles copying data between graphics buffers, does not properly validate the boundaries of these operations, leading to an out-of-bounds memory write or read. This could result in system instability or a denial of service.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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.