usb: catch attempts to submit urbs with a vmalloc'd transfer buffer

Save someone else the debug cycles of figuring out why a driver's
transfer request is failing or causing undefined system behavior.
Buffers submitted for dma must come from GFP allocated / DMA-able
memory.

Return -EAGAIN matching the return value for dma_mapping_error() cases.

Acked-by: Alan Stern <[email protected]>
Cc: Sarah Sharp <[email protected]>
Cc: Mathias Nyman <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
Signed-off-by: Mathias Nyman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 9c4e2922b04d0f2c44b405f2074085896d75a7ce..adddc66c9e8db1f66ad10ce45613c73d89479481 100644 (file)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1502,6 +1502,9 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
                                        ret = -EAGAIN;
                                else
                                        urb->transfer_flags |= URB_DMA_MAP_PAGE;
+                       } else if (is_vmalloc_addr(urb->transfer_buffer)) {
+                               WARN_ONCE(1, "transfer buffer not dma capable\n");
+                               ret = -EAGAIN;
                        } else {
                                urb->transfer_dma = dma_map_single(
                                                hcd->self.controller,