Patch "mei: move write cb to completion on credentials failures" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

mei: move write cb to completion on credentials failures

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mei-move-write-cb-to-completion-on-credentials-failures.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Alexander Usyskin <[email protected]>
Date: Wed, 14 Dec 2016 17:56:52 +0200
Subject: mei: move write cb to completion on credentials failures

From: Alexander Usyskin <[email protected]>

commit e09ee853c92011860a4bd2fbdf6126f60fc16bd3 upstream.

The credentials handling was pushed to the write handlers but error handling wasn't done properly.
Move write callbacks to completion queue to destroy them and to notify a blocked writer about the failure

---
 drivers/misc/mei/client.c |   20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

@@ -1536,7 +1536,7 @@ int mei_cl_irq_write(struct mei_cl *cl,
 
 	rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
 	if (rets < 0)
-		return rets;
+		goto err;
 
 	if (rets == 0) {
 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");

@@ -1570,11 +1570,8 @@ int mei_cl_irq_write(struct mei_cl *cl,
 			cb->buf.size, cb->buf_idx);
 
 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
-	if (rets) {
-		cl->status = rets;
-		list_move_tail(&cb->list, &cmpl_list->list);
-		return rets;
-	}
+	if (rets)
+		goto err;
 
 	cl->status = 0;
 	cl->writing_state = MEI_WRITING;

@@ -1582,14 +1579,21 @@ int mei_cl_irq_write(struct mei_cl *cl,
 	cb->completed = mei_hdr.msg_complete == 1;
 
 	if (first_chunk) {
-		if (mei_cl_tx_flow_ctrl_creds_reduce(cl))
-			return -EIO;
+		if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
+			rets = -EIO;
+			goto err;
+		}
 	}
 
 	if (mei_hdr.msg_complete)
 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
 
 	return 0;
+
+err:
+	cl->status = rets;
+	list_move_tail(&cb->list, &cmpl_list->list);
+	return rets;
 }
 
 /**

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/mei-bus-fix-mei_cldev_enable-kdoc.patch queue-4.9/mei-fix-parameter-rename-kdoc.patch queue-4.9/mei-move-write-cb-to-completion-on-credentials-failures.patch