#VU103122 NULL pointer dereference in Linux kernel - CVE-2025-21658

Vulnerability identifier: #VU103122

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-2025-21658

CWE-ID: CWE-476

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 NULL pointer dereference within the scrub_find_fill_first_stripe() function in fs/btrfs/scrub.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.12, 6.12.1, 6.12.2, 6.12.3, 6.12.4, 6.12.5, 6.12.6, 6.12.7, 6.12.8, 6.12.9

---

External links
https://git.kernel.org/stable/c/24b85a8b0310e0144da9ab30be42e87e6476638a
https://git.kernel.org/stable/c/6aecd91a5c5b68939cf4169e32bc49f3cd2dd329
https://git.kernel.org/stable/c/aee5f69f3e6cd82bfefaca1b70b40b6cd8f3f784
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.10

---

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.