[PATCH] powerpc/imc-pmu: Fix null pointer dereference in update_events_in_group

[Kunwu Chan]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: 885dcd709ba9 ("powerpc/perf: Add nest IMC PMU support")
Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
---
 arch/powerpc/perf/imc-pmu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 5d12ca386c1f..8664a7d297ad 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -299,6 +299,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
 	attr_group->attrs = attrs;
 	do {
 		ev_val_str = kasprintf(GFP_KERNEL, "event=0x%x", pmu->events[i].value);
+		if (!ev_val_str)
+			continue;
 		dev_str = device_str_attr_create(pmu->events[i].name, ev_val_str);
 		if (!dev_str)
 			continue;
@@ -306,6 +308,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
 		attrs[j++] = dev_str;
 		if (pmu->events[i].scale) {
 			ev_scale_str = kasprintf(GFP_KERNEL, "%s.scale", pmu->events[i].name);
+			if (!ev_scale_str)
+				continue;
 			dev_str = device_str_attr_create(ev_scale_str, pmu->events[i].scale);
 			if (!dev_str)
 				continue;
@@ -315,6 +319,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
 
 		if (pmu->events[i].unit) {
 			ev_unit_str = kasprintf(GFP_KERNEL, "%s.unit", pmu->events[i].name);
+			if (!ev_unit_str)
+				continue;
 			dev_str = device_str_attr_create(ev_unit_str, pmu->events[i].unit);
 			if (!dev_str)
 				continue;
-- 
2.34.1