[PATCH] powerpc: perf: Fix refcount leak bug in imc-pmu.c

From: Liang He
Date: Sat Jun 18 2022 - 03:15:01 EST


In update_events_in_group(), of_find_node_by_phandle() will return
a node pointer with refcount incremented. We should use of_node_put()
in fail path or when it is not used anymore.

Signed-off-by: Liang He <windhl@xxxxxxx>
---
arch/powerpc/perf/imc-pmu.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index d7976ab40d38..d517aba94d1b 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -240,8 +240,10 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
ct = of_get_child_count(pmu_events);

/* Get the event prefix */
- if (of_property_read_string(node, "events-prefix", &prefix))
+ if (of_property_read_string(node, "events-prefix", &prefix)) {
+ of_node_put(pmu_events);
return 0;
+ }

/* Get a global unit and scale data if available */
if (of_property_read_string(node, "scale", &g_scale))
@@ -255,8 +257,10 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)

/* Allocate memory for the events */
pmu->events = kcalloc(ct, sizeof(struct imc_events), GFP_KERNEL);
- if (!pmu->events)
+ if (!pmu->events) {
+ of_node_put(pmu_events);
return -ENOMEM;
+ }

ct = 0;
/* Parse the events and update the struct */
@@ -266,6 +270,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
ct++;
}

+ of_node_put(pmu_events);
+
/* Allocate memory for attribute group */
attr_group = kzalloc(sizeof(*attr_group), GFP_KERNEL);
if (!attr_group) {
--
2.25.1