From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48066 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727559AbeIRE3w (ORCPT ); Tue, 18 Sep 2018 00:29:52 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Gustavo A. R. Silva" , Bjorn Helgaas , Logan Gunthorpe Subject: [PATCH 4.14 018/126] switchtec: Fix Spectre v1 vulnerability Date: Tue, 18 Sep 2018 00:41:06 +0200 Message-Id: <20180917211705.882751290@linuxfoundation.org> In-Reply-To: <20180917211703.481236999@linuxfoundation.org> References: <20180917211703.481236999@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo A. R. Silva commit 46feb6b495f7628a6dbf36c4e6d80faf378372d4 upstream. p.port can is 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/pci/switch/switchtec.c:912 ioctl_port_to_pff() warn: potential spectre issue 'pcfg->dsp_pff_inst_id' [r] Fix this by sanitizing p.port before using it to index pcfg->dsp_pff_inst_id 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 Signed-off-by: Gustavo A. R. Silva Signed-off-by: Bjorn Helgaas Acked-by: Logan Gunthorpe Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/pci/switch/switchtec.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -24,6 +24,8 @@ #include #include +#include + MODULE_DESCRIPTION("Microsemi Switchtec(tm) PCIe Management Driver"); MODULE_VERSION("0.1"); MODULE_LICENSE("GPL"); @@ -1173,6 +1175,8 @@ static int ioctl_port_to_pff(struct swit default: if (p.port > ARRAY_SIZE(pcfg->dsp_pff_inst_id)) return -EINVAL; + p.port = array_index_nospec(p.port, + ARRAY_SIZE(pcfg->dsp_pff_inst_id) + 1); p.pff = ioread32(&pcfg->dsp_pff_inst_id[p.port - 1]); break; }