[PATCH] mtd: Fix possible refcounting issue when going through partition nodes

[Miquel Raynal]

Under "normal" conditions, the loop goes over all the partitions, and
'breaks' when the relevant partition is found. After the break and
outside the loop, of_node_put() is called to release the 'partitions'
of_node. However if no partition matches (I'm not sure this is a
real-world use case), the loop terminates normally and of_node_put()
gets called on the head of the list, meaning of_node_put() will be
called twice on the loop header, which is not appropriate.

Reported-by: kernel test robot <lkp at intel.com>
Reported-by: Julia Lawall <julia.lawall at inria.fr>
Closes: https://lore.kernel.org/r/202312250546.ISzglvM2-lkp@intel.com/
Cc: Christian Marangi <ansuelsmth at gmail.com>
Cc: Rafał Miłecki <rafal at milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
---
This is compile-tested only.
---
 drivers/mtd/mtdcore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index bb0759ca12f1..1049d8223898 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -620,11 +620,11 @@ static void mtd_check_of_node(struct mtd_info *mtd)
 		if (plen == mtd_name_len &&
 		    !strncmp(mtd->name, pname + offset, plen)) {
 			mtd_set_of_node(mtd, mtd_dn);
+			of_node_put(partitions);
 			break;
 		}
 	}
 
-	of_node_put(partitions);
 exit_parent:
 	of_node_put(parent_dn);
 }
-- 
2.34.1