CVE-2026-80887

In the Linux kernel, the following vulnerability has been resolved:

drm/vmwgfx: use check_add_overflow for shader size+offset bound

vmw_shader_define() validates the user-supplied shader window against

its backing buffer with

(u64)buffer->tbo.base.size < (u64)size + (u64)offset

drm_vmw_shader_create_arg::offset is __u64 in the uapi; when it is

near U64_MAX the unsigned addition wraps and the resulting tiny value

passes the check. The unbounded offset is then stored in

res->guest_memory_offset and forwarded to host SVGA shader-create

commands.

Use check_add_overflow() to detect the wrap and compare the resulting

endpoint against the buffer size.