CVE-2025-21655

MEDIUM EPSS 12.3%
Published Jan 20, 20251y ago · Modified Jun 17, 20261w ago
4.7 CVSS 3.1
Medium
Find Similar
Published Jan 20, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
4.7
Exploitability
1.0
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity High
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
12.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 9

VendorProductVersionRange
linuxlinux_kernel*≥6.1  –  <6.1.125
linuxlinux_kernel*≥6.2  –  <6.6.72
linuxlinux_kernel*≥6.7  –  <6.12.10
linuxlinux_kernel6.13any
linuxlinux_kernel6.13any
linuxlinux_kernel6.13any
linuxlinux_kernel6.13any
linuxlinux_kernel6.13any
linuxlinux_kernel6.13any

References 6

  • git.kernel.org https://git.kernel.org/stable/c/6b63308c28987c6010b1180c72a6db4df6c68033
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c9a40292a44e78f71258b8522655bffaf5753bdb
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
  • project-zero.issues.chromium.org https://project-zero.issues.chromium.org/issues/388499293
    Issue TrackingThird Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/6b63308c28987c6010b1180c72a6db4df6c68033
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c9a40292a44e78f71258b8522655bffaf5753bdb
    Patch