Race Condition Affecting kernel-libbpf-static package, versions <0:6.1.127-135.201.amzn2023
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-AMZN2023-KERNELLIBBPFSTATIC-8688815
- published6 Feb 2025
- disclosed20 Jan 2025
Introduced: 20 Jan 2025
NewCVE-2025-21655 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2023 kernel-libbpf-static to version 0:6.1.127-135.201.amzn2023 or higher.
This issue was patched in ALAS2023-2025-823.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-libbpf-static package and not the kernel-libbpf-static package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period
io_eventfd_do_signal() is invoked from an RCU callback, but when dropping the reference to the io_ev_fd, it calls io_eventfd_free() directly if the refcount drops to zero. This isn't correct, as any potential freeing of the io_ev_fd should be deferred another RCU grace period.
Just call io_eventfd_put() rather than open-code the dec-and-test and free, which will correctly defer it another RCU grace period.
References
- http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-21655
- https://git.kernel.org/stable/c/6b63308c28987c6010b1180c72a6db4df6c68033
- https://git.kernel.org/stable/c/8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10
- https://git.kernel.org/stable/c/a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7
- https://git.kernel.org/stable/c/c9a40292a44e78f71258b8522655bffaf5753bdb