Subject: CVE-2021-47251: mac80211: fix skb length check in ieee80211_scan_rx()

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

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

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

mac80211: fix skb length check in ieee80211_scan_rx()

Replace hard-coded compile-time constants for header length check
with dynamic determination based on the frame type. Otherwise, we
hit a validation WARN_ON in cfg80211 later.

[style fixes, reword commit message]

The Linux kernel CVE team has assigned CVE-2021-47251 to this issue.

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

	Issue introduced in 5.10 with commit cd418ba63f0c and fixed in 5.10.46 with commit 5a1cd67a801c
	Issue introduced in 5.10 with commit cd418ba63f0c and fixed in 5.12.13 with commit d1b949c70206
	Issue introduced in 5.10 with commit cd418ba63f0c and fixed in 5.13 with commit e298aa358f0c

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-2021-47251
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/mac80211/scan.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/5a1cd67a801cf5ef989c4783e07b86a25b143126
	https://git.kernel.org/stable/c/d1b949c70206178b12027f66edc088d40375b5cb
	https://git.kernel.org/stable/c/e298aa358f0ca658406d524b6639fe389cb6e11e