ath: Modify ath_key_delete() to not need full key entry

stable inclusion
from linux-4.19.205
commit 7c5a966edd3c6eec4a9bdf698c1f27712d1781f0
CVE: CVE-2020-3702

--------------------------------

commit 144cd24d upstream.

tkip_keymap can be used internally to avoid the reference to key->cipher
and with this, only the key index value itself is needed. This allows
ath_key_delete() call to be postponed to be handled after the upper
layer STA and key entry have already been removed. This is needed to
make ath9k key cache management safer.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201214172118.18100-5-jouni@codeaurora.org


Cc: Pali Rohár <pali@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>