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CVE-2021-47342
ext4: fix possible UAF when remounting r/o a mmp-protected file system
High7.8EPSS 0.24%
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix possible UAF when remounting r/o a mmp-protected file system After commit 618f003199c6 ("ext4: fix memory leak in ext4_fill_super"), after the file system is remounted read-only, there is a race where the kmmpd thread can exit, causing sbi->s_mmp_tsk to point at freed memory, which the call to ext4_stop_mmpd() can trip over. Fix this by only allowing kmmpd() to exit when it is stopped via ext4_stop_mmpd(). Bug-Report-Link: <[email protected]>
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.24% · top 84% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 5e4f5138bd8522ebe231a137682d3857209a2c07 – < b663890d854403e566169f7e90aed5cd6ff64f6b
- affected eb7b40d9d3785f7a131fb0b1f89bb6efa46c1833 – < 7ed572cdf11081f8f9e07abd4bea56a3f2c4edbd
- affected 618f003199c6188e01472b03cdbba227f1dc5f24 – < 61bb4a1c417e5b95d9edb4f887f131de32e419cb
- affected cecfdb9cf9a700d1037066173abac0617f6788df
- affected 5.12.18 – < 5.13
- affected 5.10.51 – < 5.10.77
References (3)
- https://git.kernel.org/stable/c/b663890d854403e566169f7e90aed5cd6ff64f6b (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/7ed572cdf11081f8f9e07abd4bea56a3f2c4edbd (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/61bb4a1c417e5b95d9edb4f887f131de32e419cb (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)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2021-47342)Record last updated .