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FAILED: patch "[PATCH] mei: bus: fix unlink on bus in error path" failed to apply to 5.4-stable tree

PATCH [email protected] 1 participant 1 message Jan 22, 2023

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Stable branch Char and misc drivers Intel management engine (mei)
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The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

a43866856125 ("mei: bus: fix unlink on bus in error path") 2cca3465147d ("mei: bus: add client dma interface") e5617d2bf549 ("mei: bus: use zero vtag for bus clients.")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a43866856125c3c432e2fbb6cc63cee1539ec4a7 Mon Sep 17 00:00:00 2001
From: Alexander Usyskin <[email protected]>
Date: Tue, 13 Dec 2022 00:02:46 +0200
Subject: [PATCH] mei: bus: fix unlink on bus in error path

Unconditional call to mei_cl_unlink in mei_cl_bus_dev_release leads to call of the mei_cl_unlink without corresponding mei_cl_link. This leads to miscalculation of open_handle_count (decrease without increase).

Call unlink in mei_cldev_enable fail path and remove blanket unlink from mei_cl_bus_dev_release.

Fixes 34f1166afd67 ("mei: bus: need to unlink client before freeing")
Cc <[email protected]>
Signed-off-by Alexander Usyskin <[email protected]>
Reviewed-by Tomas Winkler <[email protected]>
Signed-off-by Tomas Winkler <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
drivers/misc/mei/bus.c +8 -4
index 4a08b624910a..a81b890c7ee6 100644
@@ -702,13 +702,15 @@ void *mei_cldev_dma_map(struct mei_cl_device *cldev, u8 buffer_id, size_t size)
 	if (cl->state == MEI_FILE_UNINITIALIZED) {
 		ret = mei_cl_link(cl);
 		if (ret)
-			goto out;
+			goto notlinked;
 		/* update pointers */
 		cl->cldev = cldev;
 	}
 
 	ret = mei_cl_dma_alloc_and_map(cl, NULL, buffer_id, size);
-out:
+	if (ret)
+		mei_cl_unlink(cl);
+notlinked:
 	mutex_unlock(&bus->device_lock);
 	if (ret)
 		return ERR_PTR(ret);

@@ -758,7 +760,7 @@ int mei_cldev_enable(struct mei_cl_device *cldev)
 	if (cl->state == MEI_FILE_UNINITIALIZED) {
 		ret = mei_cl_link(cl);
 		if (ret)
-			goto out;
+			goto notlinked;
 		/* update pointers */
 		cl->cldev = cldev;
 	}

@@ -785,6 +787,9 @@ int mei_cldev_enable(struct mei_cl_device *cldev)
 	}
 
 out:
+	if (ret)
+		mei_cl_unlink(cl);
+notlinked:
 	mutex_unlock(&bus->device_lock);
 
 	return ret;

@@ -1277,7 +1282,6 @@ static void mei_cl_bus_dev_release(struct device *dev)
 	mei_cl_flush_queues(cldev->cl, NULL);
 	mei_me_cl_put(cldev->me_cl);
 	mei_dev_bus_put(cldev->bus);
-	mei_cl_unlink(cldev->cl);
 	kfree(cldev->cl);
 	kfree(cldev);
 }