CVE-2025-21655

Severity CVSS v4.0:

Pending analysis

Type:

CWE-416 Use After Free

Publication date:

20/01/2025

Last modified:

03/11/2025

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&#39;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.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 4.70 MEDIUM
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

4.70

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:linux:linux_kernel::::::::	6.1 (including)	6.1.125 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	6.2 (including)	6.6.72 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	6.7 (including)	6.12.10 (excluding)
cpe:2.3:o:linux:linux_kernel:6.13:rc1::::::
cpe:2.3:o:linux:linux_kernel:6.13:rc2::::::
cpe:2.3:o:linux:linux_kernel:6.13:rc3::::::
cpe:2.3:o:linux:linux_kernel:6.13:rc4::::::
cpe:2.3:o:linux:linux_kernel:6.13:rc5::::::
cpe:2.3:o:linux:linux_kernel:6.13:rc6::::::

To consult the complete list of CPE names with products and versions, see this page

CVE-2025-21655

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools