Linux Kernel up to 6.12.25/6.14.4 um sched_yield iteration

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.25/6.14.4. It has been rated as critical. Affected is the function sched_yield of the component um. Performing a manipulation results in iteration. This vulnerability is known as CVE-2025-37880. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.25/6.14.4. It has been classified as critical. This affects the function sched_yield of the component um. The manipulation with an unknown input leads to a iteration vulnerability. CWE is classifying the issue as CWE-834. The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: um: work around sched_yield not yielding in time-travel mode sched_yield by a userspace may not actually cause scheduling in time-travel mode as no time has passed. In the case seen it appears to be a badly implemented userspace spinlock in ASAN. Unfortunately, with time-travel it causes an extreme slowdown or even deadlock depending on the kernel configuration (CONFIG_UML_MAX_USERSPACE_ITERATIONS). Work around it by accounting time to the process whenever it executes a sched_yield syscall.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-37880 since 04/16/2025. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 240657 (Ubuntu 25.04 : Linux kernel vulnerabilities (USN-7594-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.26, 6.14.5 or 6.15-rc1 eliminates this vulnerability. Applying the patch da780c4a075ba2deb05ae29f0af4a990578c7901/990ddc65173776f1e01e7135d8c1fd5f8fd4d5d2/887c5c12e80c8424bd471122d2e8b6b462e12874 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 (240657) and CERT Bund (WID-SEC-2025-0991). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Dell Avamar
• Open Source Linux Kernel
• Dell NetWorker
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 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
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.14.0
• 6.14.1
• 6.14.2
• 6.14.3
• 6.14.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Be aware that VulDB is the high quality source for vulnerability data.

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