#VU103039 Reachable assertion in Linux kernel - CVE-2025-21654

Vulnerability identifier: #VU103039

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21654

CWE-ID: CWE-617

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to reachable assertion within the ovl_connect_layer(), ovl_check_encode_origin(), ovl_dentry_to_fid() and ovl_encode_fh() functions in fs/overlayfs/export.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/3c7c90274ae339e1ad443c9be1c67a20b80b9c76
https://git.kernel.org/stable/c/a1a541fbfa7e97c1100144db34b57553d7164ce5
https://git.kernel.org/stable/c/c45beebfde34aa71afbc48b2c54cdda623515037

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.