CVE-2022-49963

drm/i915/ttm: fix CCS handling

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)

N/A

CVSS

Severity:

EPSS 0.02%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/97434cb55bd884bd268626ec41489f79b261b2d4
https://git.kernel.org/stable/c/8d905254162965c8e6be697d82c7dbf5d08f574d

Frequently Asked Questions

What is the severity of CVE-2022-49963?: CVE-2022-49963 has not yet been assigned a CVSS score.
How to fix CVE-2022-49963?: To fix CVE-2022-49963, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2022-49963 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2022-49963 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2022-49963?: CVE-2022-49963 affects Linux Linux, Linux Linux.

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