linux-cve-announce - CVE-2023-53669: tcp: fix skb_copy

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: <2025100705-CVE-2023-53669-f81f@gregkh>
Date: Tue,  7 Oct 2025 17:21:28 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2023-53669: tcp: fix skb_copy_ubufs() vs BIG TCP

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

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

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

tcp: fix skb_copy_ubufs() vs BIG TCP

David Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy
using hugepages, and skb length bigger than ~68 KB.

skb_copy_ubufs() assumed it could copy all payload using up to
MAX_SKB_FRAGS order-0 pages.

This assumption broke when BIG TCP was able to put up to 512 KB per skb.

We did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45
and limit gso_max_size to 180000.

A solution is to use higher order pages if needed.

v2: add missing __GFP_COMP, or we leak memory.

The Linux kernel CVE team has assigned CVE-2023-53669 to this issue.


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

	Issue introduced in 5.19 with commit 7c4e983c4f3cf94fcd879730c6caa877e0768a4d and fixed in 6.1.29 with commit 7fa93e39fbb0566019c388a8038a4d58552e0910
	Issue introduced in 5.19 with commit 7c4e983c4f3cf94fcd879730c6caa877e0768a4d and fixed in 6.2.16 with commit 3c77a377877acbaf03cd7caa21d3644a5dd16301
	Issue introduced in 5.19 with commit 7c4e983c4f3cf94fcd879730c6caa877e0768a4d and fixed in 6.3.3 with commit 9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328f
	Issue introduced in 5.19 with commit 7c4e983c4f3cf94fcd879730c6caa877e0768a4d and fixed in 6.4 with commit 7e692df3933628d974acb9f5b334d2b3e885e2a6

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-2023-53669
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:
	net/core/skbuff.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/7fa93e39fbb0566019c388a8038a4d58552e0910
	https://git.kernel.org/stable/c/3c77a377877acbaf03cd7caa21d3644a5dd16301
	https://git.kernel.org/stable/c/9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328f
	https://git.kernel.org/stable/c/7e692df3933628d974acb9f5b334d2b3e885e2a6