Reachable assertion in Linux kernel overlayfs

1) Reachable assertion

EUVDB-ID: #VU103039

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 - Reachable Assertion

Exploit availability: No

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

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:*:*:*:*:*:*:*:*

External links

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

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.