net: ena: avoid memory access violation by validating req_id properly

Rx req_id is an index in struct ena_eth_io_rx_cdesc_base.
The driver should validate that the Rx req_id it received from
the device is in range [0, ring_size -1].  Failure to do so could
yield to potential memory access violoation.
The validation was mistakenly done when refilling
the Rx submission queue and not in Rx completion queue.

Fixes: ad974baef2 ("net: ena: add support for out of order rx buffers refill")
Signed-off-by: Noam Dagan <ndagan@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arthur Kiyanovski 2020-03-17 09:06:41 +02:00 committed by David S. Miller
parent e02ae6ed51
commit 30623e1ed1

View file

@ -1018,13 +1018,9 @@ static int ena_refill_rx_bufs(struct ena_ring *rx_ring, u32 num)
struct ena_rx_buffer *rx_info;
req_id = rx_ring->free_ids[next_to_use];
rc = validate_rx_req_id(rx_ring, req_id);
if (unlikely(rc < 0))
break;
rx_info = &rx_ring->rx_buffer_info[req_id];
rc = ena_alloc_rx_page(rx_ring, rx_info,
GFP_ATOMIC | __GFP_COMP);
if (unlikely(rc < 0)) {
@ -1379,9 +1375,15 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
struct ena_rx_buffer *rx_info;
u16 len, req_id, buf = 0;
void *va;
int rc;
len = ena_bufs[buf].len;
req_id = ena_bufs[buf].req_id;
rc = validate_rx_req_id(rx_ring, req_id);
if (unlikely(rc < 0))
return NULL;
rx_info = &rx_ring->rx_buffer_info[req_id];
if (unlikely(!rx_info->page)) {
@ -1454,6 +1456,11 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
buf++;
len = ena_bufs[buf].len;
req_id = ena_bufs[buf].req_id;
rc = validate_rx_req_id(rx_ring, req_id);
if (unlikely(rc < 0))
return NULL;
rx_info = &rx_ring->rx_buffer_info[req_id];
} while (1);