[PATCH 5.11 223/775] media: software_node: Fix refcounts in software_node_get_next_child()

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 22:10:11 EST


From: Daniel Scally <djrscally@xxxxxxxxx>

[ Upstream commit fb5ec981adf08b94e6ce27ca16b7765c94f4513c ]

The software_node_get_next_child() function currently does not hold
references to the child software_node that it finds or put the ref that
is held against the old child - fix that.

Fixes: 59abd83672f7 ("drivers: base: Introducing software nodes to the firmware node framework")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/base/swnode.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 4a4b2008fbc26..4fcc1a6fb724c 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -443,14 +443,18 @@ software_node_get_next_child(const struct fwnode_handle *fwnode,
struct swnode *c = to_swnode(child);

if (!p || list_empty(&p->children) ||
- (c && list_is_last(&c->entry, &p->children)))
+ (c && list_is_last(&c->entry, &p->children))) {
+ fwnode_handle_put(child);
return NULL;
+ }

if (c)
c = list_next_entry(c, entry);
else
c = list_first_entry(&p->children, struct swnode, entry);
- return &c->fwnode;
+
+ fwnode_handle_put(child);
+ return fwnode_handle_get(&c->fwnode);
}

static struct fwnode_handle *
--
2.27.0