linux-cve-announce - CVE-2025-40337: net: stmmac: Correctly handle Rx checksum offload errors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025120911-CVE-2025-40337-d3bd@gregkh>
Date: Tue,  9 Dec 2025 13:10:19 +0900
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-40337: net: stmmac: Correctly handle Rx checksum offload errors

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

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

net: stmmac: Correctly handle Rx checksum offload errors

The stmmac_rx function would previously set skb->ip_summed to
CHECKSUM_UNNECESSARY if hardware checksum offload (CoE) was enabled
and the packet was of a known IP ethertype.

However, this logic failed to check if the hardware had actually
reported a checksum error. The hardware status, indicating a header or
payload checksum failure, was being ignored at this stage. This could
cause corrupt packets to be passed up the network stack as valid.

This patch corrects the logic by checking the `csum_none` status flag,
which is set when the hardware reports a checksum error. If this flag
is set, skb->ip_summed is now correctly set to CHECKSUM_NONE,
ensuring the kernel's network stack will perform its own validation and
properly handle the corrupt packet.

The Linux kernel CVE team has assigned CVE-2025-40337 to this issue.

Affected and fixed versions
===========================

	Fixed in 6.6.117 with commit 63fbe0e6413279d5ea5842e2423e351ded547683
	Fixed in 6.12.58 with commit 719fcdf29051f7471d5d433475af76219019d33d
	Fixed in 6.17.8 with commit 1aa319e0f12d2d761a31556b82a5852c98eb0bea
	Fixed in 6.18 with commit ee0aace5f844ef59335148875d05bec8764e71e8

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2025-40337
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/63fbe0e6413279d5ea5842e2423e351ded547683
	https://git.kernel.org/stable/c/719fcdf29051f7471d5d433475af76219019d33d
	https://git.kernel.org/stable/c/1aa319e0f12d2d761a31556b82a5852c98eb0bea
	https://git.kernel.org/stable/c/ee0aace5f844ef59335148875d05bec8764e71e8