CVE-2022-49963 drm/i915/ttm: fix CCS handling

High 7.8 Published 18 Jun 2025 Updated 15 Oct 2026

Integer overflows in the i915 TTM driver cause kernel crashes when handling large memory objects, leading to denial of service.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2022-49963?

CVE-2022-49963 is a high-severity vulnerability in Linux kernel, published on 18 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

drm/i915/ttm: fix CCS handling

Crucible + recent Mesa seems to sometimes hit:

GEM_BUG_ON(num_ccs_blks > NUM_CCS_BLKS_PER_XFER)

And it looks like we can also trigger this with gem_lmem_swapping, if we modify the test to use slightly larger object sizes.

Looking closer it looks like we have the following issues in migrate_copy():

- We are using plain integer in various places, which we can easily overflow with a large object.

- We pass the entire object size (when the src is lmem) into emit_pte() and then try to copy it, which doesn't work, since we only have a few fixed sized windows in which to map the pages and perform the copy. With an object > 8M we therefore aren't properly copying the pages. And then with an object > 64M we trigger the GEM_BUG_ON(num_ccs_blks > NUM_CCS_BLKS_PER_XFER).

So it looks like our copy handling for any object > 8M (which is our CHUNK_SZ) is currently broken on DG2.

Testcase: igt@gem_lmem_swapping (cherry picked from commit 8676145eb2f53a9940ff70910caf0125bd8a4bc2)

Which versions are affected by CVE-2022-49963?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-49963?

Apply the vendor's patch.

Is CVE-2022-49963 being exploited?

There is no known exploitation of CVE-2022-49963 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as DEBIAN-CVE-2022-49963, GHSA-pgrp-h7rw-4vpc, UBUNTU-CVE-2022-49963.