#VU105001 NULL pointer dereference in Linux kernel - CVE-2025-21740

Vulnerability identifier: #VU105001

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-2025-21740

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 mmu_destroy_caches(), set_nx_huge_pages(), set_nx_huge_pages_recovery_param() and kvm_mmu_start_lpage_recovery() functions in arch/x86/kvm/mmu/mmu.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.13, 6.13.1, 6.13.2

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External links
https://git.kernel.org/stable/c/2b3928b7c896e5a9fb6b1373924adafe8e01a0c6
https://git.kernel.org/stable/c/43fb96ae78551d7bfa4ecca956b258f085d67c40
https://git.kernel.org/stable/c/974f85f1f7eb7dc7fce0988046e06eeccab576a7
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.3

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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.