[PATCH v2] hv_netvsc: fix a possible NULL pointer dereference in netvsc_get_ethtool_stats()

[Kangjie Lu]

In case kvmalloc_array fails, we should stop using it to avoid
NULL pointer dereference.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
---
 drivers/net/hyperv/netvsc_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index cf4897043e83..4b3a03029fe8 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1426,6 +1426,9 @@ static void netvsc_get_ethtool_stats(struct net_device *dev,
 	pcpu_sum = kvmalloc_array(num_possible_cpus(),
 				  sizeof(struct netvsc_ethtool_pcpu_stats),
 				  GFP_KERNEL);
+	if (!pcpu_sum)
+		return;
+
 	netvsc_get_pcpu_stats(dev, pcpu_sum);
 	for_each_present_cpu(cpu) {
 		struct netvsc_ethtool_pcpu_stats *this_sum = &pcpu_sum[cpu];
-- 
2.17.1