BaseFortify

Publication date: 2025-10-09

Last updated on: 2026-02-26

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring: fix incorrect io_kiocb reference in io_link_skb In io_link_skb function, there is a bug where prev_notif is incorrectly assigned using 'nd' instead of 'prev_nd'. This causes the context validation check to compare the current notification with itself instead of comparing it with the previous notification. Fix by using the correct prev_nd parameter when obtaining prev_notif.

CVSS Scores

EPSS Scores

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Meta Information

Published

2025-10-09

Last Modified

2026-02-26

Generated

2026-07-06

AI Q&A

2025-10-09

EPSS Evaluated

2026-07-05

NVD

CVE-2025-39963

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	6.17
linux	linux_kernel	From 5.15.160 (inc) to 5.16 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-401	The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Attack-Flow Graph

Executive Summary

This vulnerability is a bug in the Linux kernel's io_uring subsystem, specifically in the io_link_skb function. The issue is that a variable called prev_notif is assigned incorrectly using 'nd' instead of 'prev_nd'. This causes the validation check to compare the current notification with itself rather than with the previous notification, potentially leading to incorrect behavior in the kernel's I/O operations.

Impact Analysis

The incorrect assignment in the io_link_skb function can cause improper context validation in the Linux kernel's io_uring subsystem. This may lead to unexpected or incorrect handling of I/O notifications, which could affect system stability or reliability when performing asynchronous I/O operations.

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