CVE-2025-68184

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

drm/mediatek: Disable AFBC support on Mediatek DRM driver

Commit c410fa9b07c3 ("drm/mediatek: Add AFBC support to Mediatek DRM

driver") added AFBC support to Mediatek DRM and enabled the

32x8/split/sparse modifier.

However, this is currently broken on Mediatek MT8188 (Genio 700 EVK

platform); tested using upstream Kernel and Mesa (v25.2.1), AFBC is used by

default since Mesa v25.0.

Kernel trace reports vblank timeouts constantly, and the render is garbled:

```

[CRTC:62:crtc-0] vblank wait timed out

WARNING: CPU: 7 PID: 70 at drivers/gpu/drm/drm_atomic_helper.c:1835 drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c

[...]

Hardware name: MediaTek Genio-700 EVK (DT)

Workqueue: events_unbound commit_work

pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)

pc : drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c

lr : drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c

sp : ffff80008337bca0

x29: ffff80008337bcd0 x28: 0000000000000061 x27: 0000000000000000

x26: 0000000000000001 x25: 0000000000000000 x24: ffff0000c9dcc000

x23: 0000000000000001 x22: 0000000000000000 x21: ffff0000c66f2f80

x20: ffff0000c0d7d880 x19: 0000000000000000 x18: 000000000000000a

x17: 000000040044ffff x16: 005000f2b5503510 x15: 0000000000000000

x14: 0000000000000000 x13: 74756f2064656d69 x12: 742074696177206b

x11: 0000000000000058 x10: 0000000000000018 x9 : ffff800082396a70

x8 : 0000000000057fa8 x7 : 0000000000000cce x6 : ffff8000823eea70

x5 : ffff0001fef5f408 x4 : ffff80017ccee000 x3 : ffff0000c12cb480

x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000c12cb480

Call trace:

drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c (P)

drm_atomic_helper_commit_tail_rpm+0x64/0x80

commit_tail+0xa4/0x1a4

commit_work+0x14/0x20

process_one_work+0x150/0x290

worker_thread+0x2d0/0x3ec

kthread+0x12c/0x210

ret_from_fork+0x10/0x20

---[ end trace 0000000000000000 ]---

```

Until this gets fixed upstream, disable AFBC support on this platform, as

it's currently broken with upstream Mesa.