Upstream information

CVE-2025-40004 at MITRE

Description

In the Linux kernel, the following vulnerability has been resolved:

net/9p: Fix buffer overflow in USB transport layer

A buffer overflow vulnerability exists in the USB 9pfs transport layer
where inconsistent size validation between packet header parsing and
actual data copying allows a malicious USB host to overflow heap buffers.

The issue occurs because:
- usb9pfs_rx_header() validates only the declared size in packet header
- usb9pfs_rx_complete() uses req->actual (actual received bytes) for
memcpy

This allows an attacker to craft packets with small declared size
(bypassing validation) but large actual payload (triggering overflow
in memcpy).

Add validation in usb9pfs_rx_complete() to ensure req->actual does not
exceed the buffer capacity before copying data.

SUSE information

Overall state of this security issue: Does not affect SUSE products

SUSE Bugzilla entry: 1252310 [NEW]

No SUSE Security Announcements cross referenced.

SUSE Timeline for this CVE

CVE page created: Mon Oct 20 16:39:52 2025
CVE page last modified: Mon Oct 20 22:36:47 2025