CVE-2026-23227: drm/exynos: vidi: use ctx->lock to protect struct vidi_context member variables related to memory alloc/free

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

drm/exynos: vidi: use ctx->lock to protect struct vidicontext member variables related to memory alloc/free

Exynos Virtual Display driver performs memory alloc/free operations without lock protection, which easily causes concurrency problem.

For example, use-after-free can occur in race scenario like this: CPU0 CPU1 CPU2 ---- ---- ---- vidiconnectionioctl() if (vidi->connection) // true drmedid = drmedidalloc(); // alloc drmedid ... ctx->rawedid = drmedid; ... drmmodegetconnector() drmhelperprobesingleconnectormodes() vidigetmodes() if (ctx->rawedid) // true drmediddup(ctx->rawedid); if (!drmedid) // false ... vidiconnectionioctl() if (vidi->connection) // false drmedidfree(ctx->rawedid); // free drmedid ... drmedidalloc(drmedid->edid) kmemdup(edid); // UAF!! ...

To prevent these vulns, at least in vidicontext, member variables related to memory alloc/free should be protected with ctx->lock.