Subject: CVE-2021-47028: mt76: mt7915: fix txrate reporting

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

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

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

mt76: mt7915: fix txrate reporting

Properly check rate_info to fix unexpected reporting.

[ 1215.161863] Call trace:
[ 1215.164307]  cfg80211_calculate_bitrate+0x124/0x200 [cfg80211]
[ 1215.170139]  ieee80211s_update_metric+0x80/0xc0 [mac80211]
[ 1215.175624]  ieee80211_tx_status_ext+0x508/0x838 [mac80211]
[ 1215.181190]  mt7915_mcu_get_rx_rate+0x28c/0x8d0 [mt7915e]
[ 1215.186580]  mt7915_mac_tx_free+0x324/0x7c0 [mt7915e]
[ 1215.191623]  mt7915_queue_rx_skb+0xa8/0xd0 [mt7915e]
[ 1215.196582]  mt76_dma_cleanup+0x7b0/0x11d0 [mt76]
[ 1215.201276]  __napi_poll+0x38/0xf8
[ 1215.204668]  napi_workfn+0x40/0x80
[ 1215.208062]  process_one_work+0x1fc/0x390
[ 1215.212062]  worker_thread+0x48/0x4d0
[ 1215.215715]  kthread+0x120/0x128
[ 1215.218935]  ret_from_fork+0x10/0x1c

The Linux kernel CVE team has assigned CVE-2021-47028 to this issue.

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

	Issue introduced in 5.8 with commit e57b7901469f and fixed in 5.11.21 with commit dfc8a71448c7
	Issue introduced in 5.8 with commit e57b7901469f and fixed in 5.12.4 with commit 4bd926e5ca88
	Issue introduced in 5.8 with commit e57b7901469f and fixed in 5.13 with commit f43b941fd610

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-2021-47028
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/mt7915/mcu.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/dfc8a71448c7d4fec38fb22bdc8a76d79c14b6da
	https://git.kernel.org/stable/c/4bd926e5ca88eac4d95eacb806b229f8729bc62e
	https://git.kernel.org/stable/c/f43b941fd61003659a3f0e039595e5e525917aa8