{"cve":"CVE-2021-47649","nvd":{"published":"2025-02-26T06:37:06.687","modified":"2026-06-17T04:18:14.647","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nudmabuf: validate ubuf->pagecount\n\nSyzbot has reported GPF in sg_alloc_append_table_from_pages(). The\nproblem was in ubuf->pages == ZERO_PTR.\n\nubuf->pagecount is calculated from arguments passed from user-space. If\nuser creates udmabuf with list.size == 0 then ubuf->pagecount will be\nalso equal to zero; it causes kmalloc_array() to return ZERO_PTR.\n\nFix it by validating ubuf->pagecount before passing it to\nkmalloc_array().","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/2b6dd600dd72573c23ea180b5b0b2f1813405882","https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9","https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e","https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9","https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2021-47649","score":0.00247,"percentile":0.16077,"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."]}