{"cve":"CVE-2021-47004","nvd":{"published":"2024-02-28T09:15:38.353","modified":"2026-08-04T10:16:41.073","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid touching checkpointed data in get_victim()\n\nIn CP disabling mode, there are two issues when using LFS or SSR | AT_SSR\nmode to select victim:\n\n1. LFS is set to find source section during GC, the victim should have\nno checkpointed data, since after GC, section could not be set free for\nreuse.\n\nPreviously, we only check valid chpt blocks in current segment rather\nthan section, fix it.\n\n2. SSR | AT_SSR are set to find target segment for writes which can be\nfully filled by checkpointed and newly written blocks, we should never\nselect such segment, otherwise it can cause panic or data corruption\nduring allocation, potential case is described as below:\n\n a) target segment has 'n' (n < 512) ckpt valid blocks\n b) GC migrates 'n' valid blocks to other segment (segment is still\n    in dirty list)\n c) GC migrates '512 - n' blocks to target segment (segment has 'n'\n    cp_vblocks and '512 - n' vblocks)\n d) If GC selects target segment via {AT,}SSR allocator, however there\n    is no free space in targe segment.","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:H/A:H","score":7.1},"cwes":[],"references":["https://git.kernel.org/stable/c/105155a8146ddb54c119d8318964eef3859d109d","https://git.kernel.org/stable/c/1e116f87825f01a6380286472196882746b16f63","https://git.kernel.org/stable/c/211372b2571520e394b56b431a0705586013b3ff","https://git.kernel.org/stable/c/61461fc921b756ae16e64243f72af2bfc2e620db","https://git.kernel.org/stable/c/105155a8146ddb54c119d8318964eef3859d109d"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2021-47004","score":0.00238,"percentile":0.14921,"date":"2026-11-01"},"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."]}