[PATCH 4.17 065/324] qed: Fix possible memory leak in Rx error path handling.

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sudarsana Reddy Kalluru <sudarsana.kalluru@xxxxxxxxxx>

[ Upstream commit 4f9de4df901fb84709fe3a864dfa4eaf35700f68 ]

Memory for packet buffers need to be freed in the error paths as there is
no consumer (e.g., upper layer) for such packets and that memory will never
get freed.
The issue was uncovered when port was attacked with flood of isatap
packets, these are multicast packets hence were directed at all the PFs.
For foce PF, this meant they were routed to the ll2 module which in turn
drops such packets.

Fixes: 0a7fb11c ("qed: Add Light L2 support")
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@xxxxxxxxxx>
Signed-off-by: Ariel Elior <ariel.elior@xxxxxxxxxx>
Signed-off-by: Michal Kalderon <Michal.Kalderon@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/qlogic/qed/qed_ll2.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/qlogic/qed/qed_ll2.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
@@ -201,8 +201,9 @@ void qed_ll2b_complete_rx_packet(void *c
 
 	skb = build_skb(buffer->data, 0);
 	if (!skb) {
-		rc = -ENOMEM;
-		goto out_post;
+		DP_INFO(cdev, "Failed to build SKB\n");
+		kfree(buffer->data);
+		goto out_post1;
 	}
 
 	data->u.placement_offset += NET_SKB_PAD;
@@ -224,8 +225,14 @@ void qed_ll2b_complete_rx_packet(void *c
 		cdev->ll2->cbs->rx_cb(cdev->ll2->cb_cookie, skb,
 				      data->opaque_data_0,
 				      data->opaque_data_1);
+	} else {
+		DP_VERBOSE(p_hwfn, (NETIF_MSG_RX_STATUS | NETIF_MSG_PKTDATA |
+				    QED_MSG_LL2 | QED_MSG_STORAGE),
+			   "Dropping the packet\n");
+		kfree(buffer->data);
 	}
 
+out_post1:
 	/* Update Buffer information and update FW producer */
 	buffer->data = new_data;
 	buffer->phys_addr = new_phys_addr;