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* [v2] usb:host: fix divide-by-zero in function fhci_queue_urb
@ 2019-04-17 17:05 zhuyan
  2019-04-17 17:05 ` [PATCH v2] " zhuyan (M)
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: zhuyan @ 2019-04-17 17:05 UTC (permalink / raw)
  To: Alan Stern
  Cc: Greg KH, anton@enomsg.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org

On Wed, 17 Apr 2019, Alan Stern wrote:

> On Wed, 17 Apr 2019, zhuyan (M) wrote:
> 
> > On Tue, 16 Apr 2019 11:07:56 -0400, Alan Stern wrote:
> > 
> > > On Tue, 16 Apr 2019, zhuyan (M) wrote:
> > > > On Tue, 16 Apr 2019 at 11:45:45 +0200, Greg KH wrote:
> > > > > On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote:
> > > > > > In function fhci_queue_urb, the divisor of expression 
> > > > > > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, 
> > > > > > urb->pipe,
> > > > > > usb_pipeout(urb->pipe))) may be zero.
> > > > > 
> > > > > How can you hit that?
> > > > > 
> > > > > > When it is zero, unexpected results may occur, so it is 
> > > > > > necessary to ensure that the divisor is not zero.
> > > > > > 
> > > > > > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> > > > > 
> > > > > I need a "Full" name here, not just a single name.  Whatever you use to sign documents is good.
> > > > > 
> > > > > thanks,
> > > > > 
> > > > > greg k-h
> > > > 
> > > > In function usb_maxpacket, when ep is NULL, its return value is 0.  
> > > 
> > > fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket 
> > > size anyway.  It should use usb_endpoint_maxp(&urb->ep->desc).
> > 
> > Currently, fhci_queue_urb(), call usb_maxpacket() multiple times to 
> > calculate  the maxpacket size. The usb_maxpacket() will call 
> > usb_endpoint_maxp() to compute the maxpacket size.
> 
> I know that.  What fhci_queue_urb() is doing is wrong.  You should change it: 
> Make it call usb_endpoint_maxp directly instead of calling usb_maxpacket.
> 

From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 2001
From: zhuyan <zhuyan34@huawei.com>
Date: Thu, 18 Apr 2019 00:53:03 +0800
Subject: [PATCH] usb: host: fix divide-by-zero in function fhci_queue_urb

fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket
size anyway.It should use usb_endpoint_maxp(&urb->ep->desc).

In function fhci_queue_urb, the divisor of expression
(urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
may occur, so it is necessary to ensure that the divisor is not zero.

Signed-off-by: zhuyan <zhuyan34@huawei.com>
---
 drivers/usb/host/fhci-sched.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c
index 3d12cdd..7dcfe22 100644
--- a/drivers/usb/host/fhci-sched.c
+++ b/drivers/usb/host/fhci-sched.c
@@ -704,6 +704,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 	struct td *td;
 	u8 *data;
 	u16 cnt = 0;
+	u16 max_pkt_size = 0;
 
 	if (ed == NULL) {
 		ed = fhci_get_empty_ed(fhci);
@@ -727,8 +728,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 		}
 		ed->speed = (urb->dev->speed == USB_SPEED_LOW) ?
 			FHCI_LOW_SPEED : FHCI_FULL_SPEED;
-		ed->max_pkt_size = usb_maxpacket(urb->dev,
-			urb->pipe, usb_pipeout(urb->pipe));
+		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
 		urb->ep->hcpriv = ed;
 		fhci_dbg(fhci, "new ep speed=%d max_pkt_size=%d\n",
 			 ed->speed, ed->max_pkt_size);
@@ -765,11 +765,12 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 
 	switch (ed->mode) {
 	case FHCI_TF_BULK:
+		max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
 		if (urb->transfer_flags & URB_ZERO_PACKET &&
 				urb->transfer_buffer_length > 0 &&
+				(max_pkt_size != 0) &&
 				((urb->transfer_buffer_length %
-				usb_maxpacket(urb->dev, urb->pipe,
-				usb_pipeout(urb->pipe))) == 0))
+				max_pkt_size) == 0))
 			urb_state = US_BULK0;
 		while (data_len > 4096) {
 			td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt,
@@ -807,8 +808,8 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 		break;
 	case FHCI_TF_CTRL:
 		ed->dev_addr = usb_pipedevice(urb->pipe);
-		ed->max_pkt_size = usb_maxpacket(urb->dev, urb->pipe,
-			usb_pipeout(urb->pipe));
+		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
+
 		/* setup stage */
 		td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt++, FHCI_TA_SETUP,
 			USB_TD_TOGGLE_DATA0, urb->setup_packet, 8, 0, 0, true);

^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH v2] usb:host: fix divide-by-zero in function fhci_queue_urb
  2019-04-17 17:05 [v2] usb:host: fix divide-by-zero in function fhci_queue_urb zhuyan
@ 2019-04-17 17:05 ` zhuyan (M)
  2019-04-17 18:59 ` [v2] " Alan Stern
  2019-04-17 19:49 ` [v2] " Greg Kroah-Hartman
  2 siblings, 0 replies; 7+ messages in thread
From: zhuyan (M) @ 2019-04-17 17:05 UTC (permalink / raw)
  To: Alan Stern
  Cc: Greg KH, anton@enomsg.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org

On Wed, 17 Apr 2019, Alan Stern wrote:

> On Wed, 17 Apr 2019, zhuyan (M) wrote:
> 
> > On Tue, 16 Apr 2019 11:07:56 -0400, Alan Stern wrote:
> > 
> > > On Tue, 16 Apr 2019, zhuyan (M) wrote:
> > > > On Tue, 16 Apr 2019 at 11:45:45 +0200, Greg KH wrote:
> > > > > On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote:
> > > > > > In function fhci_queue_urb, the divisor of expression 
> > > > > > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, 
> > > > > > urb->pipe,
> > > > > > usb_pipeout(urb->pipe))) may be zero.
> > > > > 
> > > > > How can you hit that?
> > > > > 
> > > > > > When it is zero, unexpected results may occur, so it is 
> > > > > > necessary to ensure that the divisor is not zero.
> > > > > > 
> > > > > > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> > > > > 
> > > > > I need a "Full" name here, not just a single name.  Whatever you use to sign documents is good.
> > > > > 
> > > > > thanks,
> > > > > 
> > > > > greg k-h
> > > > 
> > > > In function usb_maxpacket, when ep is NULL, its return value is 0.  
> > > 
> > > fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket 
> > > size anyway.  It should use usb_endpoint_maxp(&urb->ep->desc).
> > 
> > Currently, fhci_queue_urb(), call usb_maxpacket() multiple times to 
> > calculate  the maxpacket size. The usb_maxpacket() will call 
> > usb_endpoint_maxp() to compute the maxpacket size.
> 
> I know that.  What fhci_queue_urb() is doing is wrong.  You should change it: 
> Make it call usb_endpoint_maxp directly instead of calling usb_maxpacket.
> 

From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 2001
From: zhuyan <zhuyan34@huawei.com>
Date: Thu, 18 Apr 2019 00:53:03 +0800
Subject: [PATCH] usb: host: fix divide-by-zero in function fhci_queue_urb

fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket
size anyway.It should use usb_endpoint_maxp(&urb->ep->desc).

In function fhci_queue_urb, the divisor of expression
(urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
may occur, so it is necessary to ensure that the divisor is not zero.

Signed-off-by: zhuyan <zhuyan34@huawei.com>
---
 drivers/usb/host/fhci-sched.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c
index 3d12cdd..7dcfe22 100644
--- a/drivers/usb/host/fhci-sched.c
+++ b/drivers/usb/host/fhci-sched.c
@@ -704,6 +704,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 	struct td *td;
 	u8 *data;
 	u16 cnt = 0;
+	u16 max_pkt_size = 0;
 
 	if (ed == NULL) {
 		ed = fhci_get_empty_ed(fhci);
@@ -727,8 +728,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 		}
 		ed->speed = (urb->dev->speed == USB_SPEED_LOW) ?
 			FHCI_LOW_SPEED : FHCI_FULL_SPEED;
-		ed->max_pkt_size = usb_maxpacket(urb->dev,
-			urb->pipe, usb_pipeout(urb->pipe));
+		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
 		urb->ep->hcpriv = ed;
 		fhci_dbg(fhci, "new ep speed=%d max_pkt_size=%d\n",
 			 ed->speed, ed->max_pkt_size);
@@ -765,11 +765,12 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 
 	switch (ed->mode) {
 	case FHCI_TF_BULK:
+		max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
 		if (urb->transfer_flags & URB_ZERO_PACKET &&
 				urb->transfer_buffer_length > 0 &&
+				(max_pkt_size != 0) &&
 				((urb->transfer_buffer_length %
-				usb_maxpacket(urb->dev, urb->pipe,
-				usb_pipeout(urb->pipe))) == 0))
+				max_pkt_size) == 0))
 			urb_state = US_BULK0;
 		while (data_len > 4096) {
 			td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt,
@@ -807,8 +808,8 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 		break;
 	case FHCI_TF_CTRL:
 		ed->dev_addr = usb_pipedevice(urb->pipe);
-		ed->max_pkt_size = usb_maxpacket(urb->dev, urb->pipe,
-			usb_pipeout(urb->pipe));
+		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
+
 		/* setup stage */
 		td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt++, FHCI_TA_SETUP,
 			USB_TD_TOGGLE_DATA0, urb->setup_packet, 8, 0, 0, true);
-- 
1.8.5.6


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [v2] usb:host: fix divide-by-zero in function fhci_queue_urb
@ 2019-04-17 18:59 ` Alan Stern
  2019-04-17 18:59   ` [PATCH v2] " Alan Stern
  0 siblings, 1 reply; 7+ messages in thread
From: Alan Stern @ 2019-04-17 18:59 UTC (permalink / raw)
  To: zhuyan (M)
  Cc: Greg KH, anton@enomsg.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org

On Wed, 17 Apr 2019, zhuyan (M) wrote:

> On Wed, 17 Apr 2019, Alan Stern wrote:
> 
> > On Wed, 17 Apr 2019, zhuyan (M) wrote:
> > 
> > > On Tue, 16 Apr 2019 11:07:56 -0400, Alan Stern wrote:
> > > 
> > > > On Tue, 16 Apr 2019, zhuyan (M) wrote:
> > > > > On Tue, 16 Apr 2019 at 11:45:45 +0200, Greg KH wrote:
> > > > > > On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote:
> > > > > > > In function fhci_queue_urb, the divisor of expression 
> > > > > > > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, 
> > > > > > > urb->pipe,
> > > > > > > usb_pipeout(urb->pipe))) may be zero.
> > > > > > 
> > > > > > How can you hit that?
> > > > > > 
> > > > > > > When it is zero, unexpected results may occur, so it is 
> > > > > > > necessary to ensure that the divisor is not zero.
> > > > > > > 
> > > > > > > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> > > > > > 
> > > > > > I need a "Full" name here, not just a single name.  Whatever you use to sign documents is good.
> > > > > > 
> > > > > > thanks,
> > > > > > 
> > > > > > greg k-h
> > > > > 
> > > > > In function usb_maxpacket, when ep is NULL, its return value is 0.  
> > > > 
> > > > fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket 
> > > > size anyway.  It should use usb_endpoint_maxp(&urb->ep->desc).
> > > 
> > > Currently, fhci_queue_urb(), call usb_maxpacket() multiple times to 
> > > calculate  the maxpacket size. The usb_maxpacket() will call 
> > > usb_endpoint_maxp() to compute the maxpacket size.
> > 
> > I know that.  What fhci_queue_urb() is doing is wrong.  You should change it: 
> > Make it call usb_endpoint_maxp directly instead of calling usb_maxpacket.
> > 
> 
> From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 2001
> From: zhuyan <zhuyan34@huawei.com>
> Date: Thu, 18 Apr 2019 00:53:03 +0800
> Subject: [PATCH] usb: host: fix divide-by-zero in function fhci_queue_urb
> 
> fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket
> size anyway.It should use usb_endpoint_maxp(&urb->ep->desc).
> 
> In function fhci_queue_urb, the divisor of expression
> (urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
> usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
> may occur, so it is necessary to ensure that the divisor is not zero.
> 
> Signed-off-by: zhuyan <zhuyan34@huawei.com>
> ---
>  drivers/usb/host/fhci-sched.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c
> index 3d12cdd..7dcfe22 100644
> --- a/drivers/usb/host/fhci-sched.c
> +++ b/drivers/usb/host/fhci-sched.c
> @@ -704,6 +704,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  	struct td *td;
>  	u8 *data;
>  	u16 cnt = 0;
> +	u16 max_pkt_size = 0;
>  
>  	if (ed == NULL) {
>  		ed = fhci_get_empty_ed(fhci);
> @@ -727,8 +728,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  		}
>  		ed->speed = (urb->dev->speed == USB_SPEED_LOW) ?
>  			FHCI_LOW_SPEED : FHCI_FULL_SPEED;
> -		ed->max_pkt_size = usb_maxpacket(urb->dev,
> -			urb->pipe, usb_pipeout(urb->pipe));
> +		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
>  		urb->ep->hcpriv = ed;
>  		fhci_dbg(fhci, "new ep speed=%d max_pkt_size=%d\n",
>  			 ed->speed, ed->max_pkt_size);
> @@ -765,11 +765,12 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  
>  	switch (ed->mode) {
>  	case FHCI_TF_BULK:
> +		max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
>  		if (urb->transfer_flags & URB_ZERO_PACKET &&
>  				urb->transfer_buffer_length > 0 &&
> +				(max_pkt_size != 0) &&

Now you shouldn't need to add this extra test.

Alan Stern

>  				((urb->transfer_buffer_length %
> -				usb_maxpacket(urb->dev, urb->pipe,
> -				usb_pipeout(urb->pipe))) == 0))
> +				max_pkt_size) == 0))
>  			urb_state = US_BULK0;
>  		while (data_len > 4096) {
>  			td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt,
> @@ -807,8 +808,8 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  		break;
>  	case FHCI_TF_CTRL:
>  		ed->dev_addr = usb_pipedevice(urb->pipe);
> -		ed->max_pkt_size = usb_maxpacket(urb->dev, urb->pipe,
> -			usb_pipeout(urb->pipe));
> +		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
> +
>  		/* setup stage */
>  		td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt++, FHCI_TA_SETUP,
>  			USB_TD_TOGGLE_DATA0, urb->setup_packet, 8, 0, 0, true);

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] usb:host: fix divide-by-zero in function fhci_queue_urb
  2019-04-17 18:59 ` [v2] " Alan Stern
@ 2019-04-17 18:59   ` Alan Stern
  0 siblings, 0 replies; 7+ messages in thread
From: Alan Stern @ 2019-04-17 18:59 UTC (permalink / raw)
  To: zhuyan (M)
  Cc: Greg KH, anton@enomsg.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org

On Wed, 17 Apr 2019, zhuyan (M) wrote:

> On Wed, 17 Apr 2019, Alan Stern wrote:
> 
> > On Wed, 17 Apr 2019, zhuyan (M) wrote:
> > 
> > > On Tue, 16 Apr 2019 11:07:56 -0400, Alan Stern wrote:
> > > 
> > > > On Tue, 16 Apr 2019, zhuyan (M) wrote:
> > > > > On Tue, 16 Apr 2019 at 11:45:45 +0200, Greg KH wrote:
> > > > > > On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote:
> > > > > > > In function fhci_queue_urb, the divisor of expression 
> > > > > > > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, 
> > > > > > > urb->pipe,
> > > > > > > usb_pipeout(urb->pipe))) may be zero.
> > > > > > 
> > > > > > How can you hit that?
> > > > > > 
> > > > > > > When it is zero, unexpected results may occur, so it is 
> > > > > > > necessary to ensure that the divisor is not zero.
> > > > > > > 
> > > > > > > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> > > > > > 
> > > > > > I need a "Full" name here, not just a single name.  Whatever you use to sign documents is good.
> > > > > > 
> > > > > > thanks,
> > > > > > 
> > > > > > greg k-h
> > > > > 
> > > > > In function usb_maxpacket, when ep is NULL, its return value is 0.  
> > > > 
> > > > fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket 
> > > > size anyway.  It should use usb_endpoint_maxp(&urb->ep->desc).
> > > 
> > > Currently, fhci_queue_urb(), call usb_maxpacket() multiple times to 
> > > calculate  the maxpacket size. The usb_maxpacket() will call 
> > > usb_endpoint_maxp() to compute the maxpacket size.
> > 
> > I know that.  What fhci_queue_urb() is doing is wrong.  You should change it: 
> > Make it call usb_endpoint_maxp directly instead of calling usb_maxpacket.
> > 
> 
> From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 2001
> From: zhuyan <zhuyan34@huawei.com>
> Date: Thu, 18 Apr 2019 00:53:03 +0800
> Subject: [PATCH] usb: host: fix divide-by-zero in function fhci_queue_urb
> 
> fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket
> size anyway.It should use usb_endpoint_maxp(&urb->ep->desc).
> 
> In function fhci_queue_urb, the divisor of expression
> (urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
> usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
> may occur, so it is necessary to ensure that the divisor is not zero.
> 
> Signed-off-by: zhuyan <zhuyan34@huawei.com>
> ---
>  drivers/usb/host/fhci-sched.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c
> index 3d12cdd..7dcfe22 100644
> --- a/drivers/usb/host/fhci-sched.c
> +++ b/drivers/usb/host/fhci-sched.c
> @@ -704,6 +704,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  	struct td *td;
>  	u8 *data;
>  	u16 cnt = 0;
> +	u16 max_pkt_size = 0;
>  
>  	if (ed == NULL) {
>  		ed = fhci_get_empty_ed(fhci);
> @@ -727,8 +728,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  		}
>  		ed->speed = (urb->dev->speed == USB_SPEED_LOW) ?
>  			FHCI_LOW_SPEED : FHCI_FULL_SPEED;
> -		ed->max_pkt_size = usb_maxpacket(urb->dev,
> -			urb->pipe, usb_pipeout(urb->pipe));
> +		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
>  		urb->ep->hcpriv = ed;
>  		fhci_dbg(fhci, "new ep speed=%d max_pkt_size=%d\n",
>  			 ed->speed, ed->max_pkt_size);
> @@ -765,11 +765,12 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  
>  	switch (ed->mode) {
>  	case FHCI_TF_BULK:
> +		max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
>  		if (urb->transfer_flags & URB_ZERO_PACKET &&
>  				urb->transfer_buffer_length > 0 &&
> +				(max_pkt_size != 0) &&

Now you shouldn't need to add this extra test.

Alan Stern

>  				((urb->transfer_buffer_length %
> -				usb_maxpacket(urb->dev, urb->pipe,
> -				usb_pipeout(urb->pipe))) == 0))
> +				max_pkt_size) == 0))
>  			urb_state = US_BULK0;
>  		while (data_len > 4096) {
>  			td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt,
> @@ -807,8 +808,8 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
>  		break;
>  	case FHCI_TF_CTRL:
>  		ed->dev_addr = usb_pipedevice(urb->pipe);
> -		ed->max_pkt_size = usb_maxpacket(urb->dev, urb->pipe,
> -			usb_pipeout(urb->pipe));
> +		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
> +
>  		/* setup stage */
>  		td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt++, FHCI_TA_SETUP,
>  			USB_TD_TOGGLE_DATA0, urb->setup_packet, 8, 0, 0, true);


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [v2] usb:host: fix divide-by-zero in function fhci_queue_urb
@ 2019-04-17 19:49 ` Greg Kroah-Hartman
  2019-04-17 19:49   ` [PATCH v2] " Greg KH
  0 siblings, 1 reply; 7+ messages in thread
From: Greg Kroah-Hartman @ 2019-04-17 19:49 UTC (permalink / raw)
  To: zhuyan (M)
  Cc: Alan Stern, anton@enomsg.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org

On Wed, Apr 17, 2019 at 05:05:33PM +0000, zhuyan (M) wrote:
> On Wed, 17 Apr 2019, Alan Stern wrote:
> 
> > On Wed, 17 Apr 2019, zhuyan (M) wrote:
> > 
> > > On Tue, 16 Apr 2019 11:07:56 -0400, Alan Stern wrote:
> > > 
> > > > On Tue, 16 Apr 2019, zhuyan (M) wrote:
> > > > > On Tue, 16 Apr 2019 at 11:45:45 +0200, Greg KH wrote:
> > > > > > On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote:
> > > > > > > In function fhci_queue_urb, the divisor of expression 
> > > > > > > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, 
> > > > > > > urb->pipe,
> > > > > > > usb_pipeout(urb->pipe))) may be zero.
> > > > > > 
> > > > > > How can you hit that?
> > > > > > 
> > > > > > > When it is zero, unexpected results may occur, so it is 
> > > > > > > necessary to ensure that the divisor is not zero.
> > > > > > > 
> > > > > > > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> > > > > > 
> > > > > > I need a "Full" name here, not just a single name.  Whatever you use to sign documents is good.
> > > > > > 
> > > > > > thanks,
> > > > > > 
> > > > > > greg k-h
> > > > > 
> > > > > In function usb_maxpacket, when ep is NULL, its return value is 0.  
> > > > 
> > > > fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket 
> > > > size anyway.  It should use usb_endpoint_maxp(&urb->ep->desc).
> > > 
> > > Currently, fhci_queue_urb(), call usb_maxpacket() multiple times to 
> > > calculate  the maxpacket size. The usb_maxpacket() will call 
> > > usb_endpoint_maxp() to compute the maxpacket size.
> > 
> > I know that.  What fhci_queue_urb() is doing is wrong.  You should change it: 
> > Make it call usb_endpoint_maxp directly instead of calling usb_maxpacket.
> > 
> 
> >From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 2001
> From: zhuyan <zhuyan34@huawei.com>
> Date: Thu, 18 Apr 2019 00:53:03 +0800
> Subject: [PATCH] usb: host: fix divide-by-zero in function fhci_queue_urb
> 
> fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket
> size anyway.It should use usb_endpoint_maxp(&urb->ep->desc).
> 
> In function fhci_queue_urb, the divisor of expression
> (urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
> usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
> may occur, so it is necessary to ensure that the divisor is not zero.
> 
> Signed-off-by: zhuyan <zhuyan34@huawei.com>

I still need a full name here and on the From: line :(

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] usb:host: fix divide-by-zero in function fhci_queue_urb
  2019-04-17 19:49 ` [v2] " Greg Kroah-Hartman
@ 2019-04-17 19:49   ` Greg KH
  0 siblings, 0 replies; 7+ messages in thread
From: Greg KH @ 2019-04-17 19:49 UTC (permalink / raw)
  To: zhuyan (M)
  Cc: Alan Stern, anton@enomsg.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org

On Wed, Apr 17, 2019 at 05:05:33PM +0000, zhuyan (M) wrote:
> On Wed, 17 Apr 2019, Alan Stern wrote:
> 
> > On Wed, 17 Apr 2019, zhuyan (M) wrote:
> > 
> > > On Tue, 16 Apr 2019 11:07:56 -0400, Alan Stern wrote:
> > > 
> > > > On Tue, 16 Apr 2019, zhuyan (M) wrote:
> > > > > On Tue, 16 Apr 2019 at 11:45:45 +0200, Greg KH wrote:
> > > > > > On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote:
> > > > > > > In function fhci_queue_urb, the divisor of expression 
> > > > > > > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, 
> > > > > > > urb->pipe,
> > > > > > > usb_pipeout(urb->pipe))) may be zero.
> > > > > > 
> > > > > > How can you hit that?
> > > > > > 
> > > > > > > When it is zero, unexpected results may occur, so it is 
> > > > > > > necessary to ensure that the divisor is not zero.
> > > > > > > 
> > > > > > > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> > > > > > 
> > > > > > I need a "Full" name here, not just a single name.  Whatever you use to sign documents is good.
> > > > > > 
> > > > > > thanks,
> > > > > > 
> > > > > > greg k-h
> > > > > 
> > > > > In function usb_maxpacket, when ep is NULL, its return value is 0.  
> > > > 
> > > > fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket 
> > > > size anyway.  It should use usb_endpoint_maxp(&urb->ep->desc).
> > > 
> > > Currently, fhci_queue_urb(), call usb_maxpacket() multiple times to 
> > > calculate  the maxpacket size. The usb_maxpacket() will call 
> > > usb_endpoint_maxp() to compute the maxpacket size.
> > 
> > I know that.  What fhci_queue_urb() is doing is wrong.  You should change it: 
> > Make it call usb_endpoint_maxp directly instead of calling usb_maxpacket.
> > 
> 
> >From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 2001
> From: zhuyan <zhuyan34@huawei.com>
> Date: Thu, 18 Apr 2019 00:53:03 +0800
> Subject: [PATCH] usb: host: fix divide-by-zero in function fhci_queue_urb
> 
> fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket
> size anyway.It should use usb_endpoint_maxp(&urb->ep->desc).
> 
> In function fhci_queue_urb, the divisor of expression
> (urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
> usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
> may occur, so it is necessary to ensure that the divisor is not zero.
> 
> Signed-off-by: zhuyan <zhuyan34@huawei.com>

I still need a full name here and on the From: line :(

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [v2] usb:host: fix divide-by-zero in function fhci_queue_urb
@ 2019-04-18  9:58 zhuyan
  0 siblings, 0 replies; 7+ messages in thread
From: zhuyan @ 2019-04-18  9:58 UTC (permalink / raw)
  To: Greg KH
  Cc: Alan Stern, anton@enomsg.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, zhuyan (M)

On Wed, 17 Apr 2019 21:49:03 +0200, Greg KH wrote:
> On Wed, Apr 17, 2019 at 05:05:33PM +0000, zhuyan (M) wrote:
> > On Wed, 17 Apr 2019, Alan Stern wrote:
> > 
> > > On Wed, 17 Apr 2019, zhuyan (M) wrote:
> > > 
> > > > On Tue, 16 Apr 2019 11:07:56 -0400, Alan Stern wrote:
> > > > 
> > > > > On Tue, 16 Apr 2019, zhuyan (M) wrote:
> > > > > > On Tue, 16 Apr 2019 at 11:45:45 +0200, Greg KH wrote:
> > > > > > > On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote:
> > > > > > > > In function fhci_queue_urb, the divisor of expression 
> > > > > > > > (urb->transfer_buffer_length % usb_maxpacket(urb->dev,
> > > > > > > > urb->pipe,
> > > > > > > > usb_pipeout(urb->pipe))) may be zero.
> > > > > > > 
> > > > > > > How can you hit that?
> > > > > > > 
> > > > > > > > When it is zero, unexpected results may occur, so it is 
> > > > > > > > necessary to ensure that the divisor is not zero.
> > > > > > > > 
> > > > > > > > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> > > > > > > 
> > > > > > > I need a "Full" name here, not just a single name.  Whatever you use to sign documents is good.
> > > > > > > 
> > > > > > > thanks,
> > > > > > > 
> > > > > > > greg k-h
> > > > > > 
> > > > > > In function usb_maxpacket, when ep is NULL, its return value is 0.  
> > > > > 
> > > > > fhci_queue_urb() shouldn't use urb->pipe to compute the 
> > > > > maxpacket size anyway.  It should use usb_endpoint_maxp(&urb->ep->desc).
> > > > 
> > > > Currently, fhci_queue_urb(), call usb_maxpacket() multiple times 
> > > > to calculate  the maxpacket size. The usb_maxpacket() will call
> > > > usb_endpoint_maxp() to compute the maxpacket size.
> > > 
> > > I know that.  What fhci_queue_urb() is doing is wrong.  You should change it: 
> > > Make it call usb_endpoint_maxp directly instead of calling usb_maxpacket.
> > > 
> > 
> > >From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 
> > >2001
> > From: zhuyan <zhuyan34@huawei.com>
> > Date: Thu, 18 Apr 2019 00:53:03 +0800
> > Subject: [PATCH] usb: host: fix divide-by-zero in function 
> > fhci_queue_urb
> > 
> > fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket size 
> > anyway.It should use usb_endpoint_maxp(&urb->ep->desc).
> > 
> > In function fhci_queue_urb, the divisor of expression 
> > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
> > usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected 
> > results may occur, so it is necessary to ensure that the divisor is not zero.
> > 
> > Signed-off-by: zhuyan <zhuyan34@huawei.com>
> 
> I still need a full name here and on the From: line :(

I am so sorry. I will change it.

From 1996456d0cc17b5ff7746a598ff355b25d13db3e Mon Sep 17 00:00:00 2001
From: Yan Zhu <zhuyan34@huawei.com>
Date: Thu, 18 Apr 2019 00:53:03 +0800
Subject: [PATCH] usb: host: fix divide-by-zero in function fhci_queue_urb

fhci_queue_urb() shouldn't use urb->pipe to compute the maxpacket
size anyway.It should use usb_endpoint_maxp(&urb->ep->desc).

In function fhci_queue_urb, the divisor of expression
(urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
may occur, so it is necessary to ensure that the divisor is not zero.

Signed-off-by: Yan Zhu <zhuyan34@huawei.com>
---
 drivers/usb/host/fhci-sched.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c
index 3d12cdd..7dcfe22 100644
--- a/drivers/usb/host/fhci-sched.c
+++ b/drivers/usb/host/fhci-sched.c
@@ -704,6 +704,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 	struct td *td;
 	u8 *data;
 	u16 cnt = 0;
+	u16 max_pkt_size = 0;
 
 	if (ed == NULL) {
 		ed = fhci_get_empty_ed(fhci);
@@ -727,8 +728,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 		}
 		ed->speed = (urb->dev->speed == USB_SPEED_LOW) ?
 			FHCI_LOW_SPEED : FHCI_FULL_SPEED;
-		ed->max_pkt_size = usb_maxpacket(urb->dev,
-			urb->pipe, usb_pipeout(urb->pipe));
+		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
 		urb->ep->hcpriv = ed;
 		fhci_dbg(fhci, "new ep speed=%d max_pkt_size=%d\n",
 			 ed->speed, ed->max_pkt_size);
@@ -765,11 +765,12 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 
 	switch (ed->mode) {
 	case FHCI_TF_BULK:
+		max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
 		if (urb->transfer_flags & URB_ZERO_PACKET &&
 				urb->transfer_buffer_length > 0 &&
+				(max_pkt_size != 0) &&
 				((urb->transfer_buffer_length %
-				usb_maxpacket(urb->dev, urb->pipe,
-				usb_pipeout(urb->pipe))) == 0))
+				max_pkt_size) == 0))
 			urb_state = US_BULK0;
 		while (data_len > 4096) {
 			td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt,
@@ -807,8 +808,8 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
 		break;
 	case FHCI_TF_CTRL:
 		ed->dev_addr = usb_pipedevice(urb->pipe);
-		ed->max_pkt_size = usb_maxpacket(urb->dev, urb->pipe,
-			usb_pipeout(urb->pipe));
+		ed->max_pkt_size = usb_endpoint_maxp(&urb->ep->desc);
+
 		/* setup stage */
 		td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt++, FHCI_TA_SETUP,
 			USB_TD_TOGGLE_DATA0, urb->setup_packet, 8, 0, 0, true);

^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2019-04-18  9:58 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-04-17 17:05 [v2] usb:host: fix divide-by-zero in function fhci_queue_urb zhuyan
2019-04-17 17:05 ` [PATCH v2] " zhuyan (M)
2019-04-17 18:59 ` [v2] " Alan Stern
2019-04-17 18:59   ` [PATCH v2] " Alan Stern
2019-04-17 19:49 ` [v2] " Greg Kroah-Hartman
2019-04-17 19:49   ` [PATCH v2] " Greg KH
  -- strict thread matches above, loose matches on Subject: below --
2019-04-18  9:58 [v2] " zhuyan

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