BaseFortify

Publication date: 2025-10-28

Last updated on: 2025-10-30

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix overshooting recv limit It's reported that sometimes a zcrx request can receive more than was requested. It's caused by io_zcrx_recv_skb() adjusting desc->count for all received buffers including frag lists, but then doing recursive calls to process frag list skbs, which leads to desc->count double accounting and underflow.

CVSS Scores

EPSS Scores

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Meta Information

Published

2025-10-28

Last Modified

2025-10-30

Generated

2026-07-06

AI Q&A

2025-10-28

EPSS Evaluated

2026-07-05

NVD

CVE-2025-40046

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel's io_uring subsystem involves the zcrx request sometimes receiving more data than requested. It occurs because the function io_zcrx_recv_skb() incorrectly adjusts the descriptor's count for all received buffers, including fragment lists, and then recursively processes these fragment lists. This leads to double counting and an underflow in the descriptor's count, causing the system to overshoot the receive limit.

Impact Analysis

The vulnerability can cause the system to receive more data than expected, which may lead to buffer management issues such as data corruption, unexpected behavior, or potential security risks related to handling more data than intended.

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