{"cve":"CVE-2026-64368","nvd":{"published":"2026-07-25T10:17:19.613","modified":"2026-10-19T21:17:33.260","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slab: do not limit zeroing to orig_size when only red zoning is enabled\n\nWhen init (zeroing) on allocation is requested, for kmalloc() we\ngenerally have to zero the full object size even if a smaller size is\nrequested, in order to provide krealloc()'s __GFP_ZERO guarantees.\n\nBut if we track the requested size, krealloc() uses that information to\ndo the right thing, so we can zero only the requested size. With red\nzoning also enabled, any extra size became part of the red zone, so it\nmust not be zeroed and thus we must zero only the requested size.\n\nHowever the current check is imprecise, and will trigger also when only\nSLAB_RED_ZONE is enabled without SLAB_STORE_USER (which enables tracking\nthe requested size). This means enabling red zoning alone can compromise\nkrealloc()'s __GFP_ZERO contract.\n\nFix this by using slub_debug_orig_size() instead, which is the exact\ncheck for whether the requested size is tracked. We don't need to care\nif red zoning is also enabled or not. Also update and expand the\ncomment accordingly.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.1},"cwes":["CWE-665"],"references":["https://git.kernel.org/stable/c/0d18ccef142f04433dfb2a0c120cf223d2b8a42c","https://git.kernel.org/stable/c/2382971aaaef5bf85a651234c64906f59580b8be","https://git.kernel.org/stable/c/6256899c3a34674bba6076884aedbba49fc695e4","https://git.kernel.org/stable/c/648927ceb84021a25a0fbd5673740956f318d534","https://git.kernel.org/stable/c/7e706d50fa119eead6376bf0ef973e8d73a96030"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-64368","score":0.00417,"percentile":0.35695,"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."]}