Linux Kernel up to 6.17.2 hwrng ks-sa-rng.c clk_get_rate divide by zero

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.17.2. It has been classified as critical. Affected is the function clk_get_rate of the file drivers/char/hw_random/ks-sa-rng.c of the component hwrng. This manipulation causes divide by zero. This vulnerability is registered as CVE-2025-40127. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.17.2. Affected by this vulnerability is the function clk_get_rate of the file drivers/char/hw_random/ks-sa-rng.c of the component hwrng. The manipulation with an unknown input leads to a divide by zero vulnerability. The CWE definition for the vulnerability is CWE-369. The product divides a value by zero. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: hwrng: ks-sa - fix division by zero in ks_sa_rng_init Fix division by zero in ks_sa_rng_init caused by missing clock pointer initialization. The clk_get_rate() call is performed on an uninitialized clk pointer, resulting in division by zero when calculating delay values. Add clock initialization code before using the clock. drivers/char/hw_random/ks-sa-rng.c | 7 +++++++ 1 file changed, 7 insertions(+)

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2025-40127 since 04/16/2025. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 276782 (Debian dla-4379 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.246, 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 or 6.18-rc1 eliminates this vulnerability. Applying the patch 692a04a1e0cde1d80a33df0078c755cf02cd7268/d76b099011fa056950f63d05ebb6160991242f6a/eec7e0e19c1fa75dc65e25aa6a21ef24a03849af/f4238064379a91e71a9c258996acac43c50c2094/2b6bcce32cb5aff84588a844a4d3f6dd5353b8e2/55a70e1de75e5ff5f961c79a2cdc6a4468cc2bf2/612b1dfeb414dfa780a6316014ceddf9a74ff5c0 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (276782) and CERT Bund (WID-SEC-2025-2579). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Divide by zero
CWE: CWE-369 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 276782
Nessus Name: Debian dla-4379 : linux-config-6.1 - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.246/5.15.195/6.1.156/6.6.112/6.12.53/6.17.3/6.18-rc1
Patch: 692a04a1e0cde1d80a33df0078c755cf02cd7268/d76b099011fa056950f63d05ebb6160991242f6a/eec7e0e19c1fa75dc65e25aa6a21ef24a03849af/f4238064379a91e71a9c258996acac43c50c2094/2b6bcce32cb5aff84588a844a4d3f6dd5353b8e2/55a70e1de75e5ff5f961c79a2cdc6a4468cc2bf2/612b1dfeb414dfa780a6316014ceddf9a74ff5c0

Timelineinfo

04/16/2025 CVE reserved
11/12/2025 +210 days Advisory disclosed
11/12/2025 +0 days VulDB entry created
02/08/2026 +88 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40127 (🔒)
GCVE (CVE): GCVE-0-2025-40127
GCVE (VulDB): GCVE-100-332155
CERT Bund: WID-SEC-2025-2579 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 11/12/2025 13:33
Updated: 02/08/2026 01:03
Changes: 11/12/2025 13:33 (60), 11/28/2025 21:48 (2), 12/18/2025 01:31 (7), 12/30/2025 13:54 (1), 02/08/2026 01:03 (1)
Complete: 🔍
Cache ID: 216::103

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