cve/published/2022/CVE-2022-49112.mbox

From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2022-49112: mt76: fix monitor mode crash with sdio driver

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

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

mt76: fix monitor mode crash with sdio driver

mt7921s driver may receive frames with fragment buffers. If there is a
CTS packet received in monitor mode, the payload is 10 bytes only and
need 6 bytes header padding after RXD buffer. However, only RXD in the
first linear buffer, if we pull buffer size RXD-size+6 bytes with
skb_pull(), that would trigger "BUG_ON(skb->len < skb->data_len)" in
__skb_pull().

To avoid the nonlinear buffer issue, enlarge the RXD size from 128 to
256 to make sure all MCU operation in linear buffer.

[   52.007562] kernel BUG at include/linux/skbuff.h:2313!
[   52.007578] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[   52.007987] pc : skb_pull+0x48/0x4c
[   52.008015] lr : mt7921_queue_rx_skb+0x494/0x890 [mt7921_common]
[   52.008361] Call trace:
[   52.008377]  skb_pull+0x48/0x4c
[   52.008400]  mt76s_net_worker+0x134/0x1b0 [mt76_sdio 35339a92c6eb7d4bbcc806a1d22f56365565135c]
[   52.008431]  __mt76_worker_fn+0xe8/0x170 [mt76 ef716597d11a77150bc07e3fdd68eeb0f9b56917]
[   52.008449]  kthread+0x148/0x3ac
[   52.008466]  ret_from_fork+0x10/0x30

The Linux kernel CVE team has assigned CVE-2022-49112 to this issue.


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

	Issue introduced in 4.16 with commit 7bc04215a66b60e198aecaee8418f6d79fa19faa and fixed in 5.15.34 with commit 13946d5a68efd11dd6af2f6ef4c908f6b00158a5
	Issue introduced in 4.16 with commit 7bc04215a66b60e198aecaee8418f6d79fa19faa and fixed in 5.16.20 with commit c37b4cab3d97ef64b206fca4d9daabd9aff7356e
	Issue introduced in 4.16 with commit 7bc04215a66b60e198aecaee8418f6d79fa19faa and fixed in 5.17.3 with commit 95e2af01669c7a3cb7a933cefa06361f9db15059
	Issue introduced in 4.16 with commit 7bc04215a66b60e198aecaee8418f6d79fa19faa and fixed in 5.18 with commit 123bc712b1de0805f9d683687e17b1ec2aba0b68

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-2022-49112
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/wireless/mediatek/mt76/mt76.h


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/13946d5a68efd11dd6af2f6ef4c908f6b00158a5
	https://git.kernel.org/stable/c/c37b4cab3d97ef64b206fca4d9daabd9aff7356e
	https://git.kernel.org/stable/c/95e2af01669c7a3cb7a933cefa06361f9db15059
	https://git.kernel.org/stable/c/123bc712b1de0805f9d683687e17b1ec2aba0b68