[PATCH] fpga: region: release of_parse_phandle nodes after use

From: Ian Abbott
Date: Fri Oct 27 2017 - 12:57:19 EST


Both fpga_region_get_manager() and fpga_region_get_bridges() call
of_parse_phandle(), but nothing calls of_node_put() on the returned
struct device_node pointers. Make sure to do that to stop their
reference counters getting out of whack.

Fixes: 0fa20cdfcc1f ("fpga: fpga-region: device tree control for FPGA")
Cc: <stable@xxxxxxxxxxxxxxx> # 4.10+
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/fpga/fpga-region.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index d9ab7c75b14f..e0c73ceba2ed 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -147,6 +147,7 @@ static struct fpga_manager *fpga_region_get_manager(struct fpga_region *region)
mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
if (mgr_node) {
mgr = of_fpga_mgr_get(mgr_node);
+ of_node_put(mgr_node);
of_node_put(np);
return mgr;
}
@@ -192,10 +193,13 @@ static int fpga_region_get_bridges(struct fpga_region *region,
parent_br = region_np->parent;

/* If overlay has a list of bridges, use it. */
- if (of_parse_phandle(overlay, "fpga-bridges", 0))
+ br = of_parse_phandle(overlay, "fpga-bridges", 0);
+ if (br) {
+ of_node_put(br);
np = overlay;
- else
+ } else {
np = region_np;
+ }

for (i = 0; ; i++) {
br = of_parse_phandle(np, "fpga-bridges", i);
@@ -203,12 +207,15 @@ static int fpga_region_get_bridges(struct fpga_region *region,
break;

/* If parent bridge is in list, skip it. */
- if (br == parent_br)
+ if (br == parent_br) {
+ of_node_put(br);
continue;
+ }

/* If node is a bridge, get it and add to list */
ret = fpga_bridge_get_to_list(br, region->info,
&region->bridge_list);
+ of_node_put(br);

/* If any of the bridges are in use, give up */
if (ret == -EBUSY) {
--
2.14.2