[PATCH 4.15 142/202] afs: Add missing afs_put_cell()

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@xxxxxxxxxx>

commit e44150157f42219fa5c074588efdb31ccfb197fc upstream.

afs_alloc_volume() needs to release the cell ref it obtained in the case of
an error.  Fix this by adding an afs_put_cell() call into the error path.

This can triggered when a lookup for a cell in a dynamic root or an
autocell mount returns an error whilst trying to look up the server (such
as ENOMEDIUM).  This results in an assertion failure oops when the module
is unloaded due to outstanding refs on a cell record.

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/afs/volume.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -102,6 +102,7 @@ static struct afs_volume *afs_alloc_volu
 error_2:
 	afs_put_serverlist(params->net, slist);
 error_1:
+	afs_put_cell(params->net, volume->cell);
 	kfree(volume);
 error_0:
 	return ERR_PTR(ret);