From: Martin Habets <habetsm.xilinx@xxxxxxxxx>
commit 1d5a474240407c38ca8c7484a656ee39f585399c upstream.
The RX page_ring is an optional feature that improves
performance. When allocation fails the driver can still
function, but possibly with a lower bandwidth.
Guard against dereferencing a NULL page_ring.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Signed-off-by: Martin Habets <habetsm.xilinx@xxxxxxxxx>
Reported-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/164111288276.5798.10330502993729113868.stgit@xxxxxxxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/sfc/falcon/rx.c | 5 +++++
drivers/net/ethernet/sfc/rx_common.c | 5 +++++
2 files changed, 10 insertions(+)
--- a/drivers/net/ethernet/sfc/falcon/rx.c
+++ b/drivers/net/ethernet/sfc/falcon/rx.c
@@ -110,6 +110,8 @@ static struct page *ef4_reuse_page(struc
struct ef4_rx_page_state *state;
unsigned index;
+ if (unlikely(!rx_queue->page_ring))
+ return NULL;
index = rx_queue->page_remove & rx_queue->page_ptr_mask;
page = rx_queue->page_ring[index];
if (page == NULL)
@@ -293,6 +295,9 @@ static void ef4_recycle_rx_pages(struct
{
struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
+ if (unlikely(!rx_queue->page_ring))
+ return;
+
do {
ef4_recycle_rx_page(channel, rx_buf);
rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
--- a/drivers/net/ethernet/sfc/rx_common.c
+++ b/drivers/net/ethernet/sfc/rx_common.c
@@ -45,6 +45,8 @@ static struct page *efx_reuse_page(struc
unsigned int index;
struct page *page;
+ if (unlikely(!rx_queue->page_ring))
+ return NULL;
index = rx_queue->page_remove & rx_queue->page_ptr_mask;
page = rx_queue->page_ring[index];
if (page == NULL)
@@ -114,6 +116,9 @@ void efx_recycle_rx_pages(struct efx_cha
{
struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
+ if (unlikely(!rx_queue->page_ring))
+ return;
+
do {
efx_recycle_rx_page(channel, rx_buf);
rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
