[PATCH 047/122] USB: Check results of dma_map_single

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Larry Finger <Larry.Finger@xxxxxxxxxxxx>

In map_urb_for_dma(), the DMA address returned by dma_map_single()
is not checked to determine if it is legal. This lack of checking
contributed to a problem with the libertas wireless driver
(http://marc.info/?l=linux-wireless&m=125695331205062&w=2). The
difficulty was not detected until the buffer was unmapped. By this time
memory corruption had occurred.

The situation is fixed by testing the returned DMA address, and
returning -EAGAIN if the address is invalid.

Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 drivers/usb/core/hcd.c |   14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 34de475..026ab2f 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1275,13 +1275,16 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 
 	if (usb_endpoint_xfer_control(&urb->ep->desc)
 	    && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
-		if (hcd->self.uses_dma)
+		if (hcd->self.uses_dma) {
 			urb->setup_dma = dma_map_single(
 					hcd->self.controller,
 					urb->setup_packet,
 					sizeof(struct usb_ctrlrequest),
 					DMA_TO_DEVICE);
-		else if (hcd->driver->flags & HCD_LOCAL_MEM)
+			if (dma_mapping_error(hcd->self.controller,
+						urb->setup_dma))
+				return -EAGAIN;
+		} else if (hcd->driver->flags & HCD_LOCAL_MEM)
 			ret = hcd_alloc_coherent(
 					urb->dev->bus, mem_flags,
 					&urb->setup_dma,
@@ -1293,13 +1296,16 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 	if (ret == 0 && urb->transfer_buffer_length != 0
 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
-		if (hcd->self.uses_dma)
+		if (hcd->self.uses_dma) {
 			urb->transfer_dma = dma_map_single (
 					hcd->self.controller,
 					urb->transfer_buffer,
 					urb->transfer_buffer_length,
 					dir);
-		else if (hcd->driver->flags & HCD_LOCAL_MEM) {
+			if (dma_mapping_error(hcd->self.controller,
+						urb->transfer_dma))
+				return -EAGAIN;
+		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
 			ret = hcd_alloc_coherent(
 					urb->dev->bus, mem_flags,
 					&urb->transfer_dma,
-- 
1.6.5.5

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux