Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.1, < 6.1.125 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/6b63308c28987c6010b1180c72a6db4df6c68033Patch
- https://git.kernel.org/stable/c/8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10Patch
- https://git.kernel.org/stable/c/a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7Patch
- https://git.kernel.org/stable/c/c9a40292a44e78f71258b8522655bffaf5753bdbPatch
- https://project-zero.issues.chromium.org/issues/388499293Issue TrackingThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
FAQ
What is CVE-2025-21655?
CVE-2025-21655 is a vulnerability with a CVSS score of 4.7 (MEDIUM). 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...
How severe is CVE-2025-21655?
CVE-2025-21655 has been rated MEDIUM with a CVSS base score of 4.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-21655?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.