#VU106121 Improper locking in Linux kernel - CVE-2025-21892

Vulnerability identifier: #VU106121

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-2025-21892

CWE-ID: CWE-667

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 improper locking within the mlx5r_umr_cleanup(), mlx5r_umr_recover() and mlx5r_umr_post_send_wait() functions in drivers/infiniband/hw/mlx5/umr.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

---

External links
https://git.kernel.org/stable/c/1d2b84d8d054313deed2b2fcafe1168bbcb9e99f
https://git.kernel.org/stable/c/3e3bf255992cc02404e9d209b127c1c9944239cf
https://git.kernel.org/stable/c/d97505baea64d93538b16baf14ce7b8c1fbad746

---

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.