ath9k: Clear key cache explicitly on disabling hardware

ath9k: Clear key cache explicitly on disabling hardware

Origin: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit?id=6566c207e5767deb37d283ed9f77b98439a1de4e
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2020-3702

commit 73488cb2fa3bb1ef9f6cf0d757f76958bd4deaca upstream.

Now that ath/key.c may not be explicitly clearing keys from the key
cache, clear all key cache entries when disabling hardware to make sure
no keys are left behind beyond this point.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201214172118.18100-3-jouni@codeaurora.org
Cc: Pali Rohár <pali@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name ath9k-Clear-key-cache-explicitly-on-disabling-hardwa.patch