CVE-2026-74554: wifi: ath12k: fix out-of-bounds clear_bit in ath12k_mac_dp_peer_cleanup()

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

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

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

wifi: ath12k: fix out-of-bounds clear_bit in ath12k_mac_dp_peer_cleanup()

ath12k_mac_dp_peer_cleanup() clears the ML peer ID slot on the
free_ml_peer_id_map bitmap by indexing it with dp_peer->peer_id. That is
wrong: dp_peer->peer_id for an MLO peer always carries the
ATH12K_PEER_ML_ID_VALID bit (BIT(13)), so clear_bit() is invoked with
index >= 0x2000, which is far outside the bitmap of ATH12K_MAX_MLO_PEERS
(256) bits and corrupts memory adjacent to ah->free_ml_peer_id_map. The
intended bitmap entry also never gets cleared, so subsequent
ath12k_peer_ml_alloc() calls eventually run out of IDs.

The ID without the VALID bit is what ath12k_peer_ml_alloc() returned and
is stored in ahsta->ml_peer_id. Use that instead.

While there, also reset ahsta->ml_peer_id to ATH12K_MLO_PEER_ID_INVALID so
the bitmap and ahsta->ml_peer_id stay in sync.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3

The Linux kernel CVE team has assigned CVE-2026-74554 to this issue.


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

	Issue introduced in 7.0 with commit ee16dcf573d5e3283fda601dd4bca6bc52251017 and fixed in 7.1.8 with commit 234b5cb81e6fcc1e3b31b13deff66130be55f36e
	Issue introduced in 7.0 with commit ee16dcf573d5e3283fda601dd4bca6bc52251017 and fixed in 7.2-rc6 with commit 47abd2ca281531deee38a3b3770d885e270e9fc9

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-2026-74554
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/ath/ath12k/mac.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/234b5cb81e6fcc1e3b31b13deff66130be55f36e
	https://git.kernel.org/stable/c/47abd2ca281531deee38a3b3770d885e270e9fc9