[PATCH] net: mellanox: mlxsw: fix error return code of mlxsw_sp_router_nve_promote_decap()

When fib_entry is NULL, no error return code of
mlxsw_sp_router_nve_promote_decap() is assigned.
To fix this bug, err is assigned with -EINVAL in this case.

Reported-by: TOTE Robot <redacted>
Signed-off-by: Jia-Ju Bai <redacted>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 9ce90841f92d..7b260e25df1b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -1981,8 +1981,10 @@ int mlxsw_sp_router_nve_promote_decap(struct mlxsw_sp *mlxsw_sp, u32 ul_tb_id,
 	fib_entry = mlxsw_sp_router_ip2me_fib_entry_find(mlxsw_sp, ul_tb_id,
 							 ul_proto, ul_sip,
 							 type);
-	if (!fib_entry)
+	if (!fib_entry) {
+		err = -EINVAL;
 		goto out;
+	}
 
 	fib_entry->decap.tunnel_index = tunnel_index;
 	fib_entry->type = MLXSW_SP_FIB_ENTRY_TYPE_NVE_DECAP;

-- 
2.17.1

On 06.03.2021 15:07, Jia-Ju Bai wrote:

When fib_entry is NULL, no error return code of
mlxsw_sp_router_nve_promote_decap() is assigned.
To fix this bug, err is assigned with -EINVAL in this case.

Again, are you sure this is a bug? To me it looks like it is
intentional to not return an error code if fib_entry is NULL.
Please don't blindly trust the robot results, there may
always be false positives.

On Sat, Mar 06, 2021 at 03:32:39PM +0100, Heiner Kallweit wrote:

On 06.03.2021 15:07, Jia-Ju Bai wrote:

quoted

When fib_entry is NULL, no error return code of
mlxsw_sp_router_nve_promote_decap() is assigned.
To fix this bug, err is assigned with -EINVAL in this case.

Again, are you sure this is a bug? To me it looks like it is
intentional to not return an error code if fib_entry is NULL.
Please don't blindly trust the robot results, there may
always be false positives.

Yes, it is OK not to return an error. There is even a comment above the
call to mlxsw_sp_router_ip2me_fib_entry_find():

/* It is valid to create a tunnel with a local IP and only later
 * assign this IP address to a local interface
 */

quoted

Reported-by: TOTE Robot <redacted>
Signed-off-by: Jia-Ju Bai <redacted>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 9ce90841f92d..7b260e25df1b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -1981,8 +1981,10 @@ int mlxsw_sp_router_nve_promote_decap(struct mlxsw_sp *mlxsw_sp, u32 ul_tb_id,
 	fib_entry = mlxsw_sp_router_ip2me_fib_entry_find(mlxsw_sp, ul_tb_id,
 							 ul_proto, ul_sip,
 							 type);
-	if (!fib_entry)
+	if (!fib_entry) {
+		err = -EINVAL;
 		goto out;
+	}
 
 	fib_entry->decap.tunnel_index = tunnel_index;
 	fib_entry->type = MLXSW_SP_FIB_ENTRY_TYPE_NVE_DECAP;