PT-2025-7967 · Linux+3 · Linux Kernel+3

Baokun Li

+1

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Published

2022-03-16

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Updated

2025-05-21

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CVE-2021-47656

CVSS v3.1

7.8

High

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description A use-after-free issue has been identified in the jffs2 file system. The problem occurs when mounting a jffs2 image with abnormal blocks, leading to an error in jffs2 scan eraseblock(). This error triggers the execution of jffs2 clear xattr subsystem() twice, resulting in a use-after-free condition. The issue is related to the jffs2 clear xattr subsystem() function being called in jffs2 build filesystem() and again in jffs2 do fill super(). The estimated number of potentially affected devices and real-world incidents are not provided.
Recommendations To resolve the issue, move the jffs2 clear xattr subsystem() function from 'out inohash' to 'out root' to prevent the use-after-free condition. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Use After Free

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Weakness Enumeration

Related Identifiers

BDU:2025-04432
CVE-2021-47656
OESA-2025-1317
SUSE-SU-2025:1027-1
SUSE-SU-2025:1176-1
SUSE-SU-2025:1183-1
SUSE-SU-2025:1241-1
SUSE-SU-2025_1027-1
SUSE-SU-2025_1241-1

Affected Products

Astra Linux
Linux Kernel
Red Os
Suse