{"cve":"CVE-2026-80718","nvd":{"published":"2026-08-28T08:16:57.563","modified":"2026-08-29T07:16:53.323","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk()\n\nIn pcpu_create_chunk(), nr_pages is the total contiguous backing\nallocation, i.e., nr_units * pcpu_unit_pages, but pcpu_chunk_populated()\nuses it to set chunk->populated, whose size is pcpu_unit_pages, bitmap. \nSince bit N in chunk->populated means page offset N inside every unit is\nbacked.  When nr_units > 1, the function writes beyond chunk->populated. \nFix it by using chunk->nr_pages.\n\nIt also fixes the global pcpu_nr_empty_pop_pages accounting, since\npcpu_balance_free() only iterates up to chunk->nr_pages.\n\nCommit a63d4ac4ab609 (\"percpu: make percpu-km set chunk->populated bitmap\nproperly\") introduced the bitmap overflow issue.  Later, commit\nb539b87fed37f (\"percpu: implmeent pcpu_nr_empty_pop_pages and\nchunk->nr_populated\") added pcpu_nr_empty_pop_pages and caused the\naccounting issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/01504da375f5b19df195cb1cb1cf1dd184318f97","https://git.kernel.org/stable/c/32134cf9211b83bed9076d0739c5906fbea4c763","https://git.kernel.org/stable/c/5c7fc39bf19abb38a996aaad77b3e3a8f48581c3","https://git.kernel.org/stable/c/5f43d2c1bea280dcdfabaf156c25e7402fb8039f","https://git.kernel.org/stable/c/6fc7da2a052f2825fff785e860e67183f5acaaba"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:50.842544443+00:00"},"epss":{"cve":"CVE-2026-80718","score":0.00176,"percentile":0.07068,"date":"2026-10-31"},"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."]}