CVE-2021-47004f2fs: fix to avoid touching checkpointed data in get_victim()
- 7.1HighCVSS base score
- 0.24%Exploitation in 30 daysEPSS · top 85% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid touching checkpointed data in get_victim() In CP disabling mode, there are two issues when using LFS or SSR | AT_SSR mode to select victim: 1. LFS is set to find source section during GC, the victim should have no checkpointed data, since after GC, section could not be set free for reuse. Previously, we only check valid chpt blocks in current segment rather than section, fix it. 2. SSR | AT_SSR are set to find target segment for writes which can be fully filled by checkpointed and newly written blocks, we should never select such segment, otherwise it can cause panic or data corruption during allocation, potential case is described as below: a) target segment has 'n' (n < 512) ckpt valid blocks b) GC migrates 'n' valid blocks to other segment (segment is still in dirty list) c) GC migrates '512 - n' blocks to target segment (segment has 'n' cp_vblocks and '512 - n' vblocks) d) If GC selects target segment via {AT,}SSR allocator, however there is no free space in targe segment.
Timeline
ID reserved
By Linux
- 1 day later
· 1 day later
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.24% · top 85% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Affected products
- affected 4354994f097d068a894aa1a0860da54571df3582 – < 105155a8146ddb54c119d8318964eef3859d109d
- affected 4354994f097d068a894aa1a0860da54571df3582 – < 1e116f87825f01a6380286472196882746b16f63
- affected 4354994f097d068a894aa1a0860da54571df3582 – < 211372b2571520e394b56b431a0705586013b3ff
- affected 4354994f097d068a894aa1a0860da54571df3582 – < 61461fc921b756ae16e64243f72af2bfc2e620db
- affected 4.20
- unaffected < 4.20
- unaffected 5.10.38 – ≤ 5.10.*
- unaffected 5.11.22 – ≤ 5.11.*
- unaffected 5.12.5 – ≤ 5.12.*
- unaffected 5.13 – ≤ *
References
References4
- https://git.kernel.org/stable/c/105155a8146ddb54c119d8318964eef3859d109d (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/1e116f87825f01a6380286472196882746b16f63 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/211372b2571520e394b56b431a0705586013b3ff (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/61461fc921b756ae16e64243f72af2bfc2e620db (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-33652 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-47004)Record last updated .