[PATCH] mlxsw_spectrum_router: add check for return value of 'mlxsw_sp_rif_find_by_dev'

[Natalia Petrova]

Pointer 'rif' that contains the return value of 'mlxsw_sp_rif_find_by_dev'
is checked for NULL to avoid possible undefined behavior below caused by
dereference in 'mlxsw_sp_rif_destroy'.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: e4f3c1c17b6d ("mlxsw: spectrum_router: Implement common RIF core")
Signed-off-by: Natalia Petrova <n.petrova@xxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 2c4443c6b964..4f41b83d7c9e 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -8658,7 +8658,8 @@ static int mlxsw_sp_inetaddr_bridge_event(struct mlxsw_sp *mlxsw_sp,
 		break;
 	case NETDEV_DOWN:
 		rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, l3_dev);
-		mlxsw_sp_rif_destroy(rif);
+		if (rif)
+			mlxsw_sp_rif_destroy(rif);
 		break;
 	}
 
-- 
2.34.1