Subject: CVE-2024-41090: tap: add missing verification for short frame

From: Greg Kroah-Hartman <[email-masked]>

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

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

tap: add missing verification for short frame

The cited commit missed to check against the validity of the frame length
in the tap_get_user_xdp() path, which could cause a corrupted skb to be
sent downstack. Even before the skb is transmitted, the
tap_get_user_xdp()-->skb_set_network_header() may assume the size is more
than ETH_HLEN. Once transmitted, this could either cause out-of-bound
access beyond the actual length, or confuse the underlayer with incorrect
or inconsistent header length in the skb metadata.

In the alternative path, tap_get_user() already prohibits short frame which
has the length less than Ethernet header size from being transmitted.

This is to drop any frame shorter than the Ethernet header size just like
how tap_get_user() does.

CVE: CVE-2024-41090

The Linux kernel CVE team has assigned CVE-2024-41090 to this issue.

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

	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 5.4.281 with commit 8be915fc5ff9
	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 5.10.223 with commit 7431144b406a
	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 5.15.164 with commit e5e5e63c506b
	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 6.1.102 with commit ee93e6da3037
	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 6.6.43 with commit aa6a5704cab8
	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 6.9.12 with commit 73d462a38d5f
	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 6.10.2 with commit e1a786b9bbb7
	Issue introduced in 4.20 with commit 0efac27791ee and fixed in 6.11 with commit ed7f2afdd0e0

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-2024-41090
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/tap.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/8be915fc5ff9a5e296f6538be12ea75a1a93bdea
	https://git.kernel.org/stable/c/7431144b406ae82807eb87d8c98e518475b0450f
	https://git.kernel.org/stable/c/e5e5e63c506b93b89b01f522b6a7343585f784e6
	https://git.kernel.org/stable/c/ee93e6da30377cf2a75e16cd32bb9fcd86a61c46
	https://git.kernel.org/stable/c/aa6a5704cab861c9b2ae9f475076e1881e87f5aa
	https://git.kernel.org/stable/c/73d462a38d5f782b7c872fe9ae8393d9ef5483da
	https://git.kernel.org/stable/c/e1a786b9bbb767fd1c922d424aaa8078cc542309
	https://git.kernel.org/stable/c/ed7f2afdd0e043a397677e597ced0830b83ba0b3