media: videobuf2-core: copy vb planes unconditionally

Copy the relevant data from userspace to the vb->planes unconditionally
as it's possible some of the fields may have changed after the buffer
has been validated.

Keep the dma_buf_put(planes[plane].dbuf) calls in the first
`if (!reacquired)` case, in order to be close to the plane validation code
where the buffers were got in the first place.

Cc: stable@vger.kernel.org
Fixes: 95af7c0 ("media: videobuf2-core: release all planes first in __prepare_dmabuf()")
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Tested-by: Will McVicker <willmcvicker@google.com>
Acked-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

Author: ambarus

drivers/media/common/videobuf2/videobuf2-core.c

@@ -1482,18 +1482,23 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
 			}
 			vb->planes[plane].dbuf_mapped = 1;
 		}
+	} else {
+		for (plane = 0; plane < vb->num_planes; ++plane)
+			dma_buf_put(planes[plane].dbuf);
+	}
 
-		/*
-		 * Now that everything is in order, copy relevant information
-		 * provided by userspace.
-		 */
-		for (plane = 0; plane < vb->num_planes; ++plane) {
-			vb->planes[plane].bytesused = planes[plane].bytesused;
-			vb->planes[plane].length = planes[plane].length;
-			vb->planes[plane].m.fd = planes[plane].m.fd;
-			vb->planes[plane].data_offset = planes[plane].data_offset;
-		}
+	/*
+	 * Now that everything is in order, copy relevant information
+	 * provided by userspace.
+	 */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		vb->planes[plane].bytesused = planes[plane].bytesused;
+		vb->planes[plane].length = planes[plane].length;
+		vb->planes[plane].m.fd = planes[plane].m.fd;
+		vb->planes[plane].data_offset = planes[plane].data_offset;
+	}
 
+	if (reacquired) {
 		/*
 		 * Call driver-specific initialization on the newly acquired buffer,
 		 * if provided.
@@ -1503,9 +1508,6 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
 			dprintk(q, 1, "buffer initialization failed\n");
 			goto err_put_vb2_buf;
 		}
-	} else {
-		for (plane = 0; plane < vb->num_planes; ++plane)
-			dma_buf_put(planes[plane].dbuf);
 	}
 
 	ret = call_vb_qop(vb, buf_prepare, vb);