[PATCH v2 1/1] net/ena/base: fix metrics excessive memory consumption

[<shaibran@amazon.com>]

From: Shai Brandes <shaibran@amazon.com>

[ upstream commit c8a1898f82f8c04cbe1d3e2d0eec0705386c23f7 ]

The driver accidentally allocates a huge memory
buffer for the customer metrics because it uses
an uninitialized variable for the buffer length.
This can lead to excessive memory footprint for
the driver which can even fail to initialize in
case of insufficient memory.

Bugzilla ID: 1400
Fixes: f73f53f7dc7a ("net/ena: upgrade HAL")
Cc: stable@dpdk.org

Signed-off-by: Shai Brandes <shaibran@amazon.com>
Reviewed-by: Amit Bernstein <amitbern@amazon.com>
---
 drivers/net/ena/base/ena_com.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ena/base/ena_com.c b/drivers/net/ena/base/ena_com.c
index 6953a1fa33..8ae7dcf48e 100644
--- a/drivers/net/ena/base/ena_com.c
+++ b/drivers/net/ena/base/ena_com.c
@@ -3134,16 +3134,18 @@ int ena_com_allocate_debug_area(struct ena_com_dev *ena_dev,
 int ena_com_allocate_customer_metrics_buffer(struct ena_com_dev *ena_dev)
 {
 	struct ena_customer_metrics *customer_metrics = &ena_dev->customer_metrics;
+	customer_metrics->buffer_len = ENA_CUSTOMER_METRICS_BUFFER_SIZE;
+	customer_metrics->buffer_virt_addr = NULL;
 
 	ENA_MEM_ALLOC_COHERENT(ena_dev->dmadev,
 			       customer_metrics->buffer_len,
 			       customer_metrics->buffer_virt_addr,
 			       customer_metrics->buffer_dma_addr,
 			       customer_metrics->buffer_dma_handle);
-	if (unlikely(customer_metrics->buffer_virt_addr == NULL))
+	if (unlikely(customer_metrics->buffer_virt_addr == NULL)) {
+		customer_metrics->buffer_len = 0;
 		return ENA_COM_NO_MEM;
-
-	customer_metrics->buffer_len = ENA_CUSTOMER_METRICS_BUFFER_SIZE;
+	}
 
 	return 0;
 }
-- 
2.17.1