{"cve":"CVE-2022-49963","nvd":{"published":"2025-06-18T11:15:23.570","modified":"2026-10-15T22:17:26.260","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/i915/ttm: fix CCS handling\n\nCrucible + recent Mesa seems to sometimes hit:\n\nGEM_BUG_ON(num_ccs_blks > NUM_CCS_BLKS_PER_XFER)\n\nAnd it looks like we can also trigger this with gem_lmem_swapping, if we\nmodify the test to use slightly larger object sizes.\n\nLooking closer it looks like we have the following issues in\nmigrate_copy():\n\n  - We are using plain integer in various places, which we can easily\n    overflow with a large object.\n\n  - We pass the entire object size (when the src is lmem) into\n    emit_pte() and then try to copy it, which doesn't work, since we\n    only have a few fixed sized windows in which to map the pages and\n    perform the copy. With an object > 8M we therefore aren't properly\n    copying the pages. And then with an object > 64M we trigger the\n    GEM_BUG_ON(num_ccs_blks > NUM_CCS_BLKS_PER_XFER).\n\nSo it looks like our copy handling for any object > 8M (which is our\nCHUNK_SZ) is currently broken on DG2.\n\nTestcase: igt@gem_lmem_swapping\n(cherry picked from commit 8676145eb2f53a9940ff70910caf0125bd8a4bc2)","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/8d905254162965c8e6be697d82c7dbf5d08f574d","https://git.kernel.org/stable/c/97434cb55bd884bd268626ec41489f79b261b2d4"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:03:23.287444849+00:00"},"epss":{"cve":"CVE-2022-49963","score":0.0022,"percentile":0.12457,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}