Return-path: Received: from mga03.intel.com ([134.134.136.65]:7066 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753794AbeAFBSw (ORCPT ); Fri, 5 Jan 2018 20:18:52 -0500 Subject: [PATCH 08/18] carl9170: prevent bounds-check bypass via speculative execution From: Dan Williams To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, peterz@infradead.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Elena Reshetova , gregkh@linuxfoundation.org, Christian Lamparter , tglx@linutronix.de, torvalds@linux-foundation.org, Kalle Valo , alan@linux.intel.com Date: Fri, 05 Jan 2018 17:10:37 -0800 Message-ID: <151520103755.32271.6819511294540882298.stgit@dwillia2-desk3.amr.corp.intel.com> (sfid-20180106_022227_120572_864EB35F) In-Reply-To: <151520099201.32271.4677179499894422956.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151520099201.32271.4677179499894422956.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: Static analysis reports that 'queue' may be a user controlled value that is used as a data dependency to read from the 'ar9170_qmap' array. In order to avoid potential leaks of kernel memory values, block speculative execution of the instruction stream that could issue reads based on an invalid result of 'ar9170_qmap[queue]'. In this case the value of 'ar9170_qmap[queue]' is immediately reused as an index to the 'ar->edcf' array. Based on an original patch by Elena Reshetova. Cc: Christian Lamparter Cc: Kalle Valo Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Elena Reshetova Signed-off-by: Dan Williams --- drivers/net/wireless/ath/carl9170/main.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/carl9170/main.c b/drivers/net/wireless/ath/carl9170/main.c index 988c8857d78c..0ff34cbe2b62 100644 --- a/drivers/net/wireless/ath/carl9170/main.c +++ b/drivers/net/wireless/ath/carl9170/main.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include "hw.h" @@ -1384,11 +1385,12 @@ static int carl9170_op_conf_tx(struct ieee80211_hw *hw, const struct ieee80211_tx_queue_params *param) { struct ar9170 *ar = hw->priv; + const u8 *elem; int ret; mutex_lock(&ar->mutex); - if (queue < ar->hw->queues) { - memcpy(&ar->edcf[ar9170_qmap[queue]], param, sizeof(*param)); + if ((elem = nospec_array_ptr(ar9170_qmap, queue, ar->hw->queues))) { + memcpy(&ar->edcf[*elem], param, sizeof(*param)); ret = carl9170_set_qos(ar); } else { ret = -EINVAL;