CVE-2025-40127: Linux kernel · hwrng: ks-sa – fix division by zero in ks_sa_rng_init
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1100.107~20.04.2 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1100.107~20.04.2, 5.15.0-1110.119~20.04.1, 5.15.0-1100.109~20.04.1 +67
Exploitation evidence
Disclosed: evidence found.
CVE published 12 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-14.14?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1008.8?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix has been implemented in the Linux kernel by initializing the clock pointer before use in the ks_sa_rng_init function. Users should apply the official kernel updates that include this fix. Patch status is confirmed by the description of the resolved issue. No additional mitigation steps are indicated.
Description
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(+)
References
- ubuntu.com/security/CVE-2025-40127 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40127 (opens in a new tab)
- git.kernel.org/linus/612b1dfeb414dfa780a6316014ceddf9a74ff5c0 (opens in a new tab)
- git.kernel.org/stable/c/2b6bcce32cb5aff84588a844a4d3f6dd5353b8e2 (opens in a new tab)
- git.kernel.org/stable/c/55a70e1de75e5ff5f961c79a2cdc6a4468cc2bf2 (opens in a new tab)
- git.kernel.org/stable/c/612b1dfeb414dfa780a6316014ceddf9a74ff5c0 (opens in a new tab)
- git.kernel.org/stable/c/692a04a1e0cde1d80a33df0078c755cf02cd7268 (opens in a new tab)
- git.kernel.org/stable/c/d76b099011fa056950f63d05ebb6160991242f6a (opens in a new tab)
- git.kernel.org/stable/c/eec7e0e19c1fa75dc65e25aa6a21ef24a03849af (opens in a new tab)
- git.kernel.org/stable/c/f4238064379a91e71a9c258996acac43c50c2094 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)