From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] net: cxgb3_main: fix potential Spectre v1 Date: Mon, 16 Jul 2018 20:59:58 -0500 Message-ID: <20180717015958.GA19236@embeddedor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" To: Santosh Raspatur , "David S. Miller" Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org t.qset_idx can be indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c:2286 cxgb_extension_ioctl() warn: potential spectre issue 'adapter->msix_info' Fix this by sanitizing t.qset_idx before using it to index adapter->msix_info Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva --- drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c index 7b795ed..a19172d 100644 --- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c +++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c @@ -51,6 +51,7 @@ #include #include #include +#include #include "common.h" #include "cxgb3_ioctl.h" @@ -2268,6 +2269,7 @@ static int cxgb_extension_ioctl(struct net_device *dev, void __user *useraddr) if (t.qset_idx >= nqsets) return -EINVAL; + t.qset_idx = array_index_nospec(t.qset_idx, nqsets); q = &adapter->params.sge.qset[q1 + t.qset_idx]; t.rspq_size = q->rspq_size; -- 2.7.4