CVE-2021-47342 - CVE House
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Status published High CVE-2021-47342

ext4: fix possible UAF when remounting r/o a mmp-protected file system

Vulnerability 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: <20210629143603.2166962-1-yebin10@huawei.com>

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

Affected Software

Linux
Vulnerable Versions:
5e4f5138bd8522ebe231a137682d3857209a2c07, eb7b40d9d3785f7a131fb0b1f89bb6efa46c1833, 618f003199c6188e01472b03cdbba227f1dc5f24, cecfdb9cf9a700d1037066173abac0617f6788df, 5.12.18, 5.10.51

Timeline

Official Publish: May 21st, 2024
Last Modified: May 23rd, 2026
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.