[PATCH AUTOSEL 5.10 07/14] media: atomisp: Ensure that USERPTR pointers are page aligned

[Sasha Levin <sashal@kernel.org>]

From: Hans de Goede <hdegoede@redhat.com>

[ Upstream commit 6e6c4ae0f0ba295dbf6cbd48d93bec169d6ce431 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/staging/media/atomisp/pci/atomisp_ioctl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
index 8a0648fd7c81..317db11703e6 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
@@ -1290,6 +1290,12 @@ 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) {
-- 
2.35.1