CVE-2026-68198: wifi: ath6kl: fix use-after-free in aggr_reset_state()

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

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

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

wifi: ath6kl: fix use-after-free in aggr_reset_state()

The aggr_reset_state() function uses timer_delete() (non-synchronous)
for the aggregation timer before proceeding to delete TID state and
before the structure is freed by callers like aggr_module_destroy().

If the timer callback (aggr_timeout) is executing when aggr_reset_state()
is called, the callback will continue to access aggr_conn fields like
rx_tid[] and stat[] which may be freed immediately after by
kfree(aggr_info->aggr_conn) in aggr_module_destroy().

Additionally, the timer callback can re-arm itself via mod_timer() while
aggr_reset_state() is running, creating a more complex race condition.

Use timer_delete_sync() instead to ensure any running timer callback
has completed before returning.

The Linux kernel CVE team has assigned CVE-2026-68198 to this issue.


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

	Issue introduced in 3.2 with commit bdcd81707973cf8aa9305337166f8ee842a050d4 and fixed in 6.6.151 with commit 64af6534a085f49d6ed33338a19ab9cf0d0523c9
	Issue introduced in 3.2 with commit bdcd81707973cf8aa9305337166f8ee842a050d4 and fixed in 6.12.103 with commit b5d618fd61b9069b4c0a6b487022dd3117ad5acc
	Issue introduced in 3.2 with commit bdcd81707973cf8aa9305337166f8ee842a050d4 and fixed in 6.18.42 with commit 18965470d41e69d3fc10eb62afae29d10f4cdfd1
	Issue introduced in 3.2 with commit bdcd81707973cf8aa9305337166f8ee842a050d4 and fixed in 7.1.6 with commit a3313111b5d9046af60b370c93eec105b27380c1
	Issue introduced in 3.2 with commit bdcd81707973cf8aa9305337166f8ee842a050d4 and fixed in 7.2-rc5 with commit ba7debb4dd6427386862220e8335a53a4bfc235d

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-2026-68198
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/ath6kl/txrx.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/64af6534a085f49d6ed33338a19ab9cf0d0523c9
	https://git.kernel.org/stable/c/b5d618fd61b9069b4c0a6b487022dd3117ad5acc
	https://git.kernel.org/stable/c/18965470d41e69d3fc10eb62afae29d10f4cdfd1
	https://git.kernel.org/stable/c/a3313111b5d9046af60b370c93eec105b27380c1
	https://git.kernel.org/stable/c/ba7debb4dd6427386862220e8335a53a4bfc235d