mei: fix reading large reposnes

While writting to device is limitted to max_msg_length advertized
in client properites the read can be much longer delivered consequiting chunks.

We use krealloc to enlarge the buffer when needed.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 9541aa90d8f7..71892745e2e8 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -624,7 +624,7 @@ int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
  *
  * returns 0 on success, <0 on failure.
  */
-int mei_cl_read_start(struct mei_cl *cl)
+int mei_cl_read_start(struct mei_cl *cl, size_t length)
 {
         struct mei_device *dev;
         struct mei_cl_cb *cb;
@@ -657,8 +657,9 @@ int mei_cl_read_start(struct mei_cl *cl)
         if (!cb)
                 return -ENOMEM;
 
-        rets = mei_io_cb_alloc_resp_buf(cb,
-                        dev->me_clients[i].props.max_msg_length);
+        /* always allocate at least client max message */
+        length = max_t(size_t, length, dev->me_clients[i].props.max_msg_length);
+        rets = mei_io_cb_alloc_resp_buf(cb, length);
         if (rets)
                 goto err;