[PATCH] usb: ehci: prevent bad PORTSC register access

Sascha Hauer s.hauer at pengutronix.de
Wed Aug 26 05:23:13 PDT 2015


On Tue, Aug 25, 2015 at 06:45:21PM +0300, Antony Pavlov wrote:
> On Tue, 25 Aug 2015 15:59:58 +0300
> Peter Mamonov <pmamonov at gmail.com> wrote:
> 
> > From: Kuo-Jung Su <dantesu at faraday-tech.com>
> > 
> > 1. The 'index' of ehci_submit_root() is not always > 0.
> > 
> >    e.g.
> >    While it gets invoked from usb_get_descriptor(),
> >    the 'index' is always a '0'. (See ch.9 of USB2.0)
> > 
> > 2. The PORTSC register is not always required, and thus it
> >    should only report a port error when necessary.
> >    It would cause a port scan failure if the ehci_submit_root()
> >    always gets terminated by a port error.
> > 
> > Signed-off-by: Kuo-Jung Su <dantesu at faraday-tech.com>
> > Signed-off-by: Peter Mamonov <pmamonov at gmail.com>
> > ---
> >  drivers/usb/host/ehci-hcd.c | 38 ++++++++++++++++++++++++--------------
> >  1 file changed, 24 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> > index 58c22db..1146b71 100644
> > --- a/drivers/usb/host/ehci-hcd.c
> > +++ b/drivers/usb/host/ehci-hcd.c
> > @@ -476,13 +476,8 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  	int len, srclen;
> >  	uint32_t reg;
> >  	uint32_t *status_reg;
> > +	int port = le16_to_cpu(req->index);
> >  
> > -	if (le16_to_cpu(req->index) >= CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS) {
> > -		dev_err(ehci->dev, "The request port(%d) is not configured\n",
> > -			le16_to_cpu(req->index) - 1);
> > -		return -1;
> > -	}
> > -	status_reg = (uint32_t *)&ehci->hcor->or_portsc[le16_to_cpu(req->index) - 1];
> >  	srclen = 0;
> >  
> >  	dev_dbg(ehci->dev, "req=%u (%#x), type=%u (%#x), value=%u, index=%u\n",
> > @@ -493,6 +488,21 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  	typeReq = req->request | (req->requesttype << 8);
> >  
> >  	switch (typeReq) {
> > +	case USB_REQ_GET_STATUS | ((USB_RT_PORT | USB_DIR_IN) << 8):
> > +	case USB_REQ_SET_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
> > +	case USB_REQ_CLEAR_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
> > +		if (!port || port > CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS) {
> > +			printf("The request port(%d) is not configured\n", port - 1);
> > +			return -1;
> > +		}
> > +		status_reg = (uint32_t *)&ehci->hcor->or_portsc[port - 1];
> > +		break;
> > +	default:
> > +		status_reg = NULL;
> > +		break;
> > +	}
> > +
> > +	switch (typeReq) {
> >  	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
> >  		switch (le16_to_cpu(req->value) >> 8) {
> >  		case USB_DT_DEVICE:
> > @@ -571,7 +581,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  		if (reg & EHCI_PS_OCA)
> >  			tmpbuf[0] |= USB_PORT_STAT_OVERCURRENT;
> >  		if (reg & EHCI_PS_PR &&
> > -		    (ehci->portreset & (1 << le16_to_cpu(req->index)))) {
> > +		    (ehci->portreset & (1 << port))) {
> >  			int ret;
> >  			/* force reset to complete */
> >  			reg = reg & ~(EHCI_PS_PR | EHCI_PS_CLEAR);
> > @@ -581,7 +591,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  				tmpbuf[0] |= USB_PORT_STAT_RESET;
> >  			else
> >  				dev_err(ehci->dev, "port(%d) reset error\n",
> > -					le16_to_cpu(req->index) - 1);
> > +					port - 1);
> >  		}
> >  		if (reg & EHCI_PS_PP)
> >  			tmpbuf[1] |= USB_PORT_STAT_POWER >> 8;
> > @@ -608,7 +618,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  			tmpbuf[2] |= USB_PORT_STAT_C_ENABLE;
> >  		if (reg & EHCI_PS_OCC)
> >  			tmpbuf[2] |= USB_PORT_STAT_C_OVERCURRENT;
> > -		if (ehci->portreset & (1 << le16_to_cpu(req->index)))
> > +		if (ehci->portreset & (1 << port))
> >  			tmpbuf[2] |= USB_PORT_STAT_C_RESET;
> >  
> >  		srcptr = tmpbuf;
> > @@ -634,7 +644,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  			    EHCI_PS_IS_LOWSPEED(reg)) {
> >  				/* Low speed device, give up ownership. */
> >  				dev_dbg(ehci->dev, "port %d low speed --> companion\n",
> > -				      req->index - 1);
> > +				      port - 1);
> >  				reg |= EHCI_PS_PO;
> >  				ehci_writel(status_reg, reg);
> >  				break;
> > @@ -651,7 +661,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  				 */
> >  				ehci_powerup_fixup(ehci);
> >  				mdelay(50);
> > -				ehci->portreset |= 1 << le16_to_cpu(req->index);
> > +				ehci->portreset |= 1 << port;
> >  				/* terminate the reset */
> >  				ehci_writel(status_reg, reg & ~EHCI_PS_PR);
> >  				/*
> > @@ -663,10 +673,10 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  						2 * 1000);
> >  				if (!ret)
> >  					ehci->portreset |=
> > -						1 << le16_to_cpu(req->index);
> > +						1 << port;
> >  				else
> >  					dev_err(ehci->dev, "port(%d) reset error\n",
> > -						le16_to_cpu(req->index) - 1);
> > +						port - 1);
> >  
> >  			}
> >  			break;
> > @@ -698,7 +708,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
> >  			reg |= EHCI_PS_OCC;
> >  			break;
> >  		case USB_PORT_FEAT_C_RESET:
> > -			ehci->portreset &= ~(1 << le16_to_cpu(req->index));
> > +			ehci->portreset &= ~(1 << port);
> >  			break;
> >  		default:
> >  			dev_dbg(ehci->dev, "unknown feature %x\n", le16_to_cpu(req->value));
> > -- 
> > 2.1.4
> > 
> 
> 
> Actually this patch combines two U-boot patches:
> 
>   * usb: ehci: prevent bad PORTSC register access (http://lists.denx.de/pipermail/u-boot/2013-May/154319.html)
>   * usb: Add new command to set USB 2.0 port test modes (http://lists.denx.de/pipermail/u-boot/2013-March/148104.html)

Not really. This patch contains only the parts of "usb: Add new command
to set USB 2.0 port test modes" which are necessary to make this one
apply. I splitted this up to two patches while applying with the patch
below.

Sascha

-----------------------------8<-----------------------

>From 484a1fb56890fee13a73070e0d868a3349a47c19 Mon Sep 17 00:00:00 2001
From: Kuo-Jung Su <dantesu at faraday-tech.com>
Date: Tue, 25 Aug 2015 15:59:58 +0300
Subject: [PATCH 2/3] usb: ehci: replace multiple use of
 le16_to_cpu(req->index) with variable

This is part of U-Boot commit:

7d9aa8f usb: Add new command to set USB 2.0 port test modes

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/usb/host/ehci-hcd.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 0e7c595..8a6bbc9 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -475,10 +475,11 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 	int len, srclen;
 	uint32_t reg;
 	uint32_t *status_reg;
+	int port = le16_to_cpu(req->index);
 
 	if (le16_to_cpu(req->index) >= CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS) {
 		dev_err(ehci->dev, "The request port(%d) is not configured\n",
-			le16_to_cpu(req->index) - 1);
+				port - 1);
 		return -1;
 	}
 	status_reg = (uint32_t *)&ehci->hcor->or_portsc[le16_to_cpu(req->index) - 1];
@@ -570,7 +571,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 		if (reg & EHCI_PS_OCA)
 			tmpbuf[0] |= USB_PORT_STAT_OVERCURRENT;
 		if (reg & EHCI_PS_PR &&
-		    (ehci->portreset & (1 << le16_to_cpu(req->index)))) {
+		    (ehci->portreset & (1 << port))) {
 			int ret;
 			/* force reset to complete */
 			reg = reg & ~(EHCI_PS_PR | EHCI_PS_CLEAR);
@@ -580,7 +581,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 				tmpbuf[0] |= USB_PORT_STAT_RESET;
 			else
 				dev_err(ehci->dev, "port(%d) reset error\n",
-					le16_to_cpu(req->index) - 1);
+					port - 1);
 		}
 		if (reg & EHCI_PS_PP)
 			tmpbuf[1] |= USB_PORT_STAT_POWER >> 8;
@@ -607,7 +608,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 			tmpbuf[2] |= USB_PORT_STAT_C_ENABLE;
 		if (reg & EHCI_PS_OCC)
 			tmpbuf[2] |= USB_PORT_STAT_C_OVERCURRENT;
-		if (ehci->portreset & (1 << le16_to_cpu(req->index)))
+		if (ehci->portreset & (1 << port))
 			tmpbuf[2] |= USB_PORT_STAT_C_RESET;
 
 		srcptr = tmpbuf;
@@ -633,7 +634,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 			    EHCI_PS_IS_LOWSPEED(reg)) {
 				/* Low speed device, give up ownership. */
 				dev_dbg(ehci->dev, "port %d low speed --> companion\n",
-				      req->index - 1);
+				      port - 1);
 				reg |= EHCI_PS_PO;
 				ehci_writel(status_reg, reg);
 				break;
@@ -650,7 +651,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 				 */
 				ehci_powerup_fixup(ehci);
 				mdelay(50);
-				ehci->portreset |= 1 << le16_to_cpu(req->index);
+				ehci->portreset |= 1 << port;
 				/* terminate the reset */
 				ehci_writel(status_reg, reg & ~EHCI_PS_PR);
 				/*
@@ -662,10 +663,10 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 						2 * 1000);
 				if (!ret)
 					ehci->portreset |=
-						1 << le16_to_cpu(req->index);
+						1 << port;
 				else
 					dev_err(ehci->dev, "port(%d) reset error\n",
-						le16_to_cpu(req->index) - 1);
+						port - 1);
 
 			}
 			break;
@@ -697,7 +698,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 			reg |= EHCI_PS_OCC;
 			break;
 		case USB_PORT_FEAT_C_RESET:
-			ehci->portreset &= ~(1 << le16_to_cpu(req->index));
+			ehci->portreset &= ~(1 << port);
 			break;
 		default:
 			dev_dbg(ehci->dev, "unknown feature %x\n", le16_to_cpu(req->value));
-- 
2.5.0

-- 
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