media: atomisp: Ensure that USERPTR pointers are page aligned

The atomisp code needs USERPTR pointers to be page aligned,
otherwise bad things (scribbling over other parts of the
process' RAM) happen.

Add a check to ensure this and exit VIDIOC_QBUF calls with
unaligned pointers with -EINVAL.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
index 7ecee39ef5a471db29797ac11f2757168b3b6a54..d0b5dacbb20aa0dd5a5dd739a931794dbac330cc 100644 (file)
--- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
@@ -1345,6 +1345,12 @@ static int atomisp_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
         * address and reprograme out page table properly
         */
        if (buf->memory == V4L2_MEMORY_USERPTR) {
+               if (offset_in_page(buf->m.userptr)) {
+                       dev_err(isp->dev, "Error userptr is not page aligned.\n");
+                       ret = -EINVAL;
+                       goto error;
+               }
+
                vb = pipe->capq.bufs[buf->index];
                vm_mem = vb->priv;
                if (!vm_mem) {