CVE-2026-64117: wifi: mac80211: capture fast-RX rate before mesh reuses skb->cb

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

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

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

wifi: mac80211: capture fast-RX rate before mesh reuses skb->cb

ieee80211_invoke_fast_rx() reads RX status through
IEEE80211_SKB_RXCB(skb), which aliases the same skb->cb storage
that ieee80211_rx_mesh_data() reuses as IEEE80211_TX_INFO.  In the
unicast forward path, mesh_data does:

	info = IEEE80211_SKB_CB(fwd_skb);
	memset(info, 0, sizeof(*info));

on the same skb the caller still names via rx->skb, then either
queues the skb for TX (success) or kfree_skb()'s it (no-route)
before returning RX_QUEUED.  The caller's RX_QUEUED arm then
calls sta_stats_encode_rate(status) on memory that is either
zeroed (success path) or freed (no-route path).  The latter is
KASAN slab-use-after-free in ieee80211_prepare_and_rx_handle.

Fix by encoding the rate from status before invoking
ieee80211_rx_mesh_data(), so the RX_QUEUED arm consumes a value
captured while status was still backed by valid memory.

The Linux kernel CVE team has assigned CVE-2026-64117 to this issue.


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

	Issue introduced in 6.4 with commit 3468e1e0c639032a603450f0830ccabfa76f5806 and fixed in 7.0.11 with commit 2fb64f94f9afb774f2fa0c7835727d7a67f89f07
	Issue introduced in 6.4 with commit 3468e1e0c639032a603450f0830ccabfa76f5806 and fixed in 7.1 with commit d71c841be5d9e586ee7f36c0dc8ed4db0d9a1349

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-2026-64117
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/rx.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/2fb64f94f9afb774f2fa0c7835727d7a67f89f07
	https://git.kernel.org/stable/c/d71c841be5d9e586ee7f36c0dc8ed4db0d9a1349