CVE-2026-68326: wifi: mwifiex: bound uAP association event IEs to the event buffer

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

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

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

wifi: mwifiex: bound uAP association event IEs to the event buffer

mwifiex_process_uap_event() handles EVENT_UAP_STA_ASSOC by exposing the
(re)association request IEs that the firmware copies into the event:

	sinfo->assoc_req_ies = &event->data[len];
	len = (u8 *)sinfo->assoc_req_ies - (u8 *)&event->frame_control;
	sinfo->assoc_req_ies_len = le16_to_cpu(event->len) - (u16)len;

event->len is supplied by the device firmware and is never validated,
and the subtraction is unchecked.  assoc_req_ies points into
adapter->event_body[MAX_EVENT_SIZE], a fixed-size array embedded in the
kmalloc()'d struct mwifiex_adapter.

On the ap_11n_enabled path mwifiex_set_sta_ht_cap() walks these IEs with
cfg80211_find_ie(), whose for_each_element() loop dereferences each
element header.  A firmware-reported event->len larger than the bytes
actually received makes assoc_req_ies_len describe IEs that extend past
event_body, so the walk reads out of the adapter slab object, a
slab-out-of-bounds read (KASAN: slab-out-of-bounds in cfg80211_find_ie).
An event->len smaller than the header instead makes the int subtraction
negative, which wraps to a huge size_t when stored in assoc_req_ies_len.
The same length is handed to cfg80211_new_sta(), so a more modest
over-claim can also copy stale event_body bytes into the
NL80211_CMD_NEW_STATION notification.

A malicious or malfunctioning mwifiex device (USB/SDIO/PCIe) can deliver
such an event while the interface is in AP/uAP mode.

Validate event->len before use: reject a length that underflows the
header or that would place the IEs outside the event_body[] buffer the
event was copied into.  event->len here is struct mwifiex_assoc_event.len,
a payload field internal to this event, not the transport frame length,
so it is validated in this handler rather than at the generic
MWIFIEX_TYPE_EVENT receive path, which only sees the event cause and the
transport frame length.  The bound is against event_body[MAX_EVENT_SIZE]
rather than the actually-received length because the transports store the
event differently (USB and SDIO leave the 4-byte event header in
event_skb, PCIe strips it via skb_pull), whereas event_body is the single
fixed buffer all of them copy the event into.  This is the event-path
analogue of the receive-path bounds checks added in commit 119585281617
("wifi: mwifiex: Fix OOB and integer underflow when rx packets").

The Linux kernel CVE team has assigned CVE-2026-68326 to this issue.


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

	Issue introduced in 3.5 with commit e568634ae7ac379661c90731d480e067929420a1 and fixed in 6.6.148 with commit a3f47d7c75ddad1a14621a309286f9fae3cba191
	Issue introduced in 3.5 with commit e568634ae7ac379661c90731d480e067929420a1 and fixed in 6.12.101 with commit ad26c75ae25749313248f06510ebe43b5bf4adcc
	Issue introduced in 3.5 with commit e568634ae7ac379661c90731d480e067929420a1 and fixed in 6.18.42 with commit d21464d93f8ba464dc3d7b4b31c6e0adcd9f659c
	Issue introduced in 3.5 with commit e568634ae7ac379661c90731d480e067929420a1 and fixed in 7.1.6 with commit b6766d7ea43edf5de9d5a572bc58b631d09efe4b
	Issue introduced in 3.5 with commit e568634ae7ac379661c90731d480e067929420a1 and fixed in 7.2-rc5 with commit f0858bfc7d3cab411a447b88e3ef970e575032c9

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-2026-68326
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/marvell/mwifiex/uap_event.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/a3f47d7c75ddad1a14621a309286f9fae3cba191
	https://git.kernel.org/stable/c/ad26c75ae25749313248f06510ebe43b5bf4adcc
	https://git.kernel.org/stable/c/d21464d93f8ba464dc3d7b4b31c6e0adcd9f659c
	https://git.kernel.org/stable/c/b6766d7ea43edf5de9d5a572bc58b631d09efe4b
	https://git.kernel.org/stable/c/f0858bfc7d3cab411a447b88e3ef970e575032c9