What’s Vulnerable › Vulnerabilities

CVE-2025-37880: um: work around sched_yield not yielding in time-travel mode

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-05-09 · updated 2026-06-17
• Weakness: CWE-667

Description

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.

Affected products

• Linux kernel: before 6.14.5 — fixed in 6.14.5

How to fix

Upgrade to a fixed version: Linux kernel 6.14.5. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/887c5c12e80c8424bd471122d2e8b6b462e12874
• https://git.kernel.org/stable/c/990ddc65173776f1e01e7135d8c1fd5f8fd4d5d2

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