[PATCH] net: dsa: felix: fix possible NULL pointer dereference

[Zheng Yongjun]

As the possible failure of the allocation, kzalloc() may return NULL
pointer.
Therefore, it should be better to check the 'sgi' in order to prevent
the dereference of NULL pointer.

Fixes: 23ae3a7877718 ("net: dsa: felix: add stream gate settings for psfpq").
Signed-off-by: Zheng Yongjun <zhengyongjun3@xxxxxxxxxx>
---
 drivers/net/dsa/ocelot/felix_vsc9959.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index 33f0ceae381d..2875b5250856 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1940,6 +1940,10 @@ static int vsc9959_psfp_filter_add(struct ocelot *ocelot, int port,
 		case FLOW_ACTION_GATE:
 			size = struct_size(sgi, entries, a->gate.num_entries);
 			sgi = kzalloc(size, GFP_KERNEL);
+			if (!sgi) {
+				ret = -ENOMEM;
+				goto err;
+			}
 			vsc9959_psfp_parse_gate(a, sgi);
 			ret = vsc9959_psfp_sgi_table_add(ocelot, sgi);
 			if (ret) {
-- 
2.17.1