media: platform: davinci: return -EINVAL for VPFE_CMD_S_CCDC_RAW_PARAMS ioctl

this patch makes sure VPFE_CMD_S_CCDC_RAW_PARAMS ioctl no longer works
for vpfe_capture driver with a minimal patch suitable for backporting.

- This ioctl was never in public api and was only defined in kernel header.
- The function set_params constantly mixes up pointers and phys_addr_t
  numbers.
- This is part of a 'VPFE_CMD_S_CCDC_RAW_PARAMS' ioctl command that is
  described as an 'experimental ioctl that will change in future kernels'.
- The code to allocate the table never gets called after we copy_from_user
  the user input over the kernel settings, and then compare them
  for inequality.
- We then go on to use an address provided by user space as both the
  __user pointer for input and pass it through phys_to_virt to come up
  with a kernel pointer to copy the data to. This looks like a trivially
  exploitable root hole.

Due to these reasons we make sure this ioctl now returns -EINVAL and backport
this patch as far as possible.

Fixes: 5f15fbb68fd7 ("V4L/DVB (12251): v4l: dm644x ccdc module for vpfe capture driver")

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: <stable@vger.kernel.org>      # for v3.7 and up
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/platform/davinci/vpfe_capture.c b/drivers/media/platform/davinci/vpfe_capture.c
index e3fe3e0635aa87806abf4b15e4ba83264ec8b557..1831bf5ccca5f81196dd14b1ebb2138ff95cb092 100644 (file)
--- a/drivers/media/platform/davinci/vpfe_capture.c
+++ b/drivers/media/platform/davinci/vpfe_capture.c
@@ -1719,27 +1719,9 @@ static long vpfe_param_handler(struct file *file, void *priv,
 
        switch (cmd) {
        case VPFE_CMD_S_CCDC_RAW_PARAMS:
+               ret = -EINVAL;
                v4l2_warn(&vpfe_dev->v4l2_dev,
-                         "VPFE_CMD_S_CCDC_RAW_PARAMS: experimental ioctl\n");
-               if (ccdc_dev->hw_ops.set_params) {
-                       ret = ccdc_dev->hw_ops.set_params(param);
-                       if (ret) {
-                               v4l2_dbg(1, debug, &vpfe_dev->v4l2_dev,
-                                       "Error setting parameters in CCDC\n");
-                               goto unlock_out;
-                       }
-                       ret = vpfe_get_ccdc_image_format(vpfe_dev,
-                                                        &vpfe_dev->fmt);
-                       if (ret < 0) {
-                               v4l2_dbg(1, debug, &vpfe_dev->v4l2_dev,
-                                       "Invalid image format at CCDC\n");
-                               goto unlock_out;
-                       }
-               } else {
-                       ret = -EINVAL;
-                       v4l2_dbg(1, debug, &vpfe_dev->v4l2_dev,
-                               "VPFE_CMD_S_CCDC_RAW_PARAMS not supported\n");
-               }
+                       "VPFE_CMD_S_CCDC_RAW_PARAMS not supported\n");
                break;
        default:
                ret = -ENOTTY;