V4L/DVB (9569): uvcvideo: Sort the frame descriptors during parsing

The UVC specification does not require frame descriptors to be sorted by
bFrameIndex. At least one camera (145f:013e) is known not to sort the
descriptors properly, so they need to be sorted during parsing as the driver
then accesses them by index.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 22 insertions, 3 deletions

diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
index 07cf9517bb4e..11398ee66320 100644
--- a/drivers/media/video/uvc/uvc_driver.c
+++ b/drivers/media/video/uvc/uvc_driver.c
@@ -288,8 +288,10 @@ static int uvc_parse_format(struct uvc_device *dev,
         struct uvc_format_desc *fmtdesc;
         struct uvc_frame *frame;
         const unsigned char *start = buffer;
+        unsigned char *_buffer;
         unsigned int interval;
         unsigned int i, n;
+        int _buflen;
         __u8 ftype;
 
         format->type = buffer[2];
@@ -410,12 +412,20 @@ static int uvc_parse_format(struct uvc_device *dev,
         buflen -= buffer[0];
         buffer += buffer[0];
 
+        /* Count the number of frame descriptors to test the bFrameIndex
+         * field when parsing the descriptors. We can't rely on the
+         * bNumFrameDescriptors field as some cameras don't initialize it
+         * properly.
+         */
+        for (_buflen = buflen, _buffer = buffer;
+             _buflen > 2 && _buffer[2] == ftype;
+             _buflen -= _buffer[0], _buffer += _buffer[0])
+                format->nframes++;
+
         /* Parse the frame descriptors. Only uncompressed, MJPEG and frame
          * based formats have frame descriptors.
          */
         while (buflen > 2 && buffer[2] == ftype) {
-                frame = &format->frame[format->nframes];
-
                 if (ftype != VS_FRAME_FRAME_BASED)
                         n = buflen > 25 ? buffer[25] : 0;
                 else
@@ -430,6 +440,16 @@ static int uvc_parse_format(struct uvc_device *dev,
                         return -EINVAL;
                 }
 
+                if (buffer[3] - 1 >= format->nframes) {
+                        uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                               "interface %d frame index %u out of range\n",
+                               dev->udev->devnum, alts->desc.bInterfaceNumber,
+                               buffer[3]);
+                        return -EINVAL;
+                }
+
+                frame = &format->frame[buffer[3] - 1];
+
                 frame->bFrameIndex = buffer[3];
                 frame->bmCapabilities = buffer[4];
                 frame->wWidth = le16_to_cpup((__le16 *)&buffer[5]);
@@ -486,7 +506,6 @@ static int uvc_parse_format(struct uvc_device *dev,
                         10000000/frame->dwDefaultFrameInterval,
                         (100000000/frame->dwDefaultFrameInterval)%10);
 
-                format->nframes++;
                 buflen -= buffer[0];
                 buffer += buffer[0];
         }