[PATCH net v2] ixgbe: add NULL pointer check before calling xdp_rxq_info_reg

From: Yunjian Wang <redacted>

The rx_ring->q_vector could be NULL, so it needs to be checked before
calling xdp_rxq_info_reg.

Fixes: b02e5a0ebb172 ("xsk: Propagate napi_id to XDP socket Rx path")
Addresses-Coverity: ("Dereference after null check")
Signed-off-by: Yunjian Wang <redacted>
---
v2:
  * fix commit log
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 6cbbe09ce8a0..7b76b3f448f7 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -6586,8 +6586,9 @@ int ixgbe_setup_rx_resources(struct ixgbe_adapter *adapter,
 	rx_ring->next_to_use = 0;
 
 	/* XDP RX-queue info */
-	if (xdp_rxq_info_reg(&rx_ring->xdp_rxq, adapter->netdev,
-			     rx_ring->queue_index, rx_ring->q_vector->napi.napi_id) < 0)
+	if (rx_ring->q_vector && xdp_rxq_info_reg(&rx_ring->xdp_rxq, adapter->netdev,
+						  rx_ring->queue_index,
+						  rx_ring->q_vector->napi.napi_id) < 0)
 		goto err;
 
 	rx_ring->xdp_prog = adapter->xdp_prog;

-- 
2.23.0

On Fri, Jan 22, 2021 at 5:29 AM wangyunjian [off-list ref] wrote:

From: Yunjian Wang <redacted>

The rx_ring->q_vector could be NULL, so it needs to be checked before
calling xdp_rxq_info_reg.

Fixes: b02e5a0ebb172 ("xsk: Propagate napi_id to XDP socket Rx path")
Addresses-Coverity: ("Dereference after null check")
Signed-off-by: Yunjian Wang <redacted>

This is kind of a big escape for the driver. From what I can tell it
looks like the "ethtool -t" test now causes a NULL pointer
dereference.

As far as the patch itself it looks good to me. This should probably
be pushed for any of the other Intel drivers that follow a similar
model as I suspect they were exhibit the same symptom with "ethtool
-t" triggering a NULL pointer dereference.

Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>

On Fri, 2021-01-22 at 09:54 -0800, Alexander Duyck wrote:

On Fri, Jan 22, 2021 at 5:29 AM wangyunjian [off-list ref]
wrote:

quoted

From: Yunjian Wang <redacted>

The rx_ring->q_vector could be NULL, so it needs to be checked
before
calling xdp_rxq_info_reg.

Fixes: b02e5a0ebb172 ("xsk: Propagate napi_id to XDP socket Rx
path")
Addresses-Coverity: ("Dereference after null check")
Signed-off-by: Yunjian Wang <redacted>

This is kind of a big escape for the driver. From what I can tell it
looks like the "ethtool -t" test now causes a NULL pointer
dereference.

As far as the patch itself it looks good to me. This should probably
be pushed for any of the other Intel drivers that follow a similar
model as I suspect they were exhibit the same symptom with "ethtool
-t" triggering a NULL pointer dereference.

Thanks for the review Alex. We'll look into fixing the other Intel
drivers.

Thanks,
Tony