[PATCH 5.11 069/122] ixgbe: Fix NULL pointer dereference in ethtool loopback test

Greg Kroah-Hartman
2021-04-19T13:15:15Z

From: Alexander Duyck <alexanderduyck@fb.com>

commit 31166efb1cee348eb6314e9c0095d84cbeb66b9d upstream.

The ixgbe driver currently generates a NULL pointer dereference when
performing the ethtool loopback test. This is due to the fact that there
isn't a q_vector associated with the test ring when it is setup as
interrupts are not normally added to the test rings.

To address this I have added code that will check for a q_vector before
returning a napi_id value. If a q_vector is not present it will return a
value of 0.

Fixes: b02e5a0ebb17 ("xsk: Propagate napi_id to XDP socket Rx path")
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Dave Switzer <david.switzer@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -6540,6 +6540,13 @@ err_setup_tx:
return err;
}

+static int ixgbe_rx_napi_id(struct ixgbe_ring *rx_ring)
+{
+ struct ixgbe_q_vector *q_vector = rx_ring->q_vector;
+
+ return q_vector ? q_vector->napi.napi_id : 0;
+}
+
/**
* ixgbe_setup_rx_resources - allocate Rx resources (Descriptors)
* @adapter: pointer to ixgbe_adapter
@@ -6587,7 +6594,7 @@ int ixgbe_setup_rx_resources(struct ixgb

/* 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)
+ rx_ring->queue_index, ixgbe_rx_napi_id(rx_ring)) < 0)
goto err;

rx_ring->xdp_prog = adapter->xdp_prog;