Staging: rspiusb: Check usb_buffer_map_sg() retval

usb_buffer_map_sg() may return -1, check this directly.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/staging/rspiusb/rspiusb.c b/drivers/staging/rspiusb/rspiusb.c
index 04e2f92c0f62..0495fbfe59d9 100644
--- a/drivers/staging/rspiusb/rspiusb.c
+++ b/drivers/staging/rspiusb/rspiusb.c
@@ -611,6 +611,7 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
         int i = 0;
         int k = 0;
         int err = 0;
+        int ret;
         struct page **maplist_p;
         int numPagesRequired;
 
@@ -687,9 +688,16 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
         } else {
                 pdx->sgl[frameInfo][0].length = count;
         }
-        pdx->sgEntries[frameInfo] =
-            usb_buffer_map_sg(pdx->udev, epAddr, pdx->sgl[frameInfo],
-                              pdx->maplist_numPagesMapped[frameInfo]);
+        ret = usb_buffer_map_sg(pdx->udev, epAddr, pdx->sgl[frameInfo],
+                        pdx->maplist_numPagesMapped[frameInfo]);
+        if (ret < 0) {
+                vfree(maplist_p);
+                dbg("usb_buffer_map_sg() failed");
+                return -EINVAL;
+        }
+
+        pdx->sgEntries[frameInfo] = ret;
+
         dbg("number of sgEntries = %d", pdx->sgEntries[frameInfo]);
         pdx->userBufMapped = 1;
         vfree(maplist_p);
@@ -716,8 +724,6 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
                 pdx->PixelUrb[frameInfo][i]->transfer_flags =
                     URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT;
         }
-        if (i == 0)
-                return -EINVAL;
         /* only interrupt when last URB completes */
         pdx->PixelUrb[frameInfo][--i]->transfer_flags &= ~URB_NO_INTERRUPT;
         pdx->pendedPixelUrbs[frameInfo] =