From: Francesco Dolcini <francesco.dolcini@toradex.com>
To: "Richard Zhu" <hongxing.zhu@nxp.com>,
"Lucas Stach" <l.stach@pengutronix.de>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Sascha Hauer" <s.hauer@pengutronix.de>,
"Pengutronix Kernel Team" <kernel@pengutronix.de>,
"Fabio Estevam" <festevam@gmail.com>,
"NXP Linux Team" <linux-imx@nxp.com>,
"Jason Liu" <jason.hui.liu@nxp.com>
Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
Shawn Guo <shawnguo@kernel.org>,
Francesco Dolcini <francesco.dolcini@toradex.com>
Subject: [PATCH v1] PCI: imx6: Handle the abort from user-space
Date: Mon, 31 Jan 2022 08:52:35 +0100 [thread overview]
Message-ID: <20220131075235.787432-1-francesco.dolcini@toradex.com> (raw)
From: Jason Liu <jason.hui.liu@nxp.com>
The driver install one hook to handle the external abort, but issue
is that if the abort introduced from user space code, the following
code unsigned long instr = *(unsigned long *)pc; which will created
another data-abort(page domain fault) if CONFIG_CPU_SW_DOMAIN_PAN.
The patch does not intent to use copy_from_user and then do the hack
due to the security consideration. In fact, we can just return and
report the external abort to user-space.
Link: https://lore.kernel.org/all/20220128082920.591115-1-francesco.dolcini@toradex.com
Signed-off-by: Jason Liu <jason.hui.liu@nxp.com>
Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
---
rfc -> v1:
* added Acked-by Lucas Stach
* include correct header for user_mode()
---
drivers/pci/controller/dwc/pci-imx6.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 6974bd5aa116..c47a05332a94 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -22,6 +22,7 @@
#include <linux/of_address.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
+#include <linux/ptrace.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/resource.h>
@@ -297,8 +298,15 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
unsigned int fsr, struct pt_regs *regs)
{
unsigned long pc = instruction_pointer(regs);
- unsigned long instr = *(unsigned long *)pc;
- int reg = (instr >> 12) & 15;
+ unsigned long instr;
+ int reg;
+
+ /* if the abort from user-space, just return and report it */
+ if (user_mode(regs))
+ return 1;
+
+ instr = *(unsigned long *)pc;
+ reg = (instr >> 12) & 15;
/*
* If the instruction being executed was a read,
--
2.25.1
next reply other threads:[~2022-01-31 7:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-31 7:52 Francesco Dolcini [this message]
2022-02-10 8:00 ` [PATCH v1] PCI: imx6: Handle the abort from user-space Francesco Dolcini
2022-02-23 13:00 ` Lorenzo Pieralisi
2022-02-23 17:46 ` Francesco Dolcini
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