[PATCH 4.19 19/38] sfc: falcon: Check null pointer of rx_queue->page_ring

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Jiasheng Jiang <jiasheng@iscas.ac.cn>

[ Upstream commit 9b8bdd1eb5890aeeab7391dddcf8bd51f7b07216 ]

Because of the possible failure of the kcalloc, it should be better to
set rx_queue->page_ptr_mask to 0 when it happens in order to maintain
the consistency.

Fixes: 5a6681e22c14 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Link: https://lore.kernel.org/r/20211220140344.978408-1-jiasheng@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/sfc/falcon/rx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/sfc/falcon/rx.c b/drivers/net/ethernet/sfc/falcon/rx.c
index 02456ed13a7d4..5b93a3af4575d 100644
--- a/drivers/net/ethernet/sfc/falcon/rx.c
+++ b/drivers/net/ethernet/sfc/falcon/rx.c
@@ -732,7 +732,10 @@ static void ef4_init_rx_recycle_ring(struct ef4_nic *efx,
 					    efx->rx_bufs_per_page);
 	rx_queue->page_ring = kcalloc(page_ring_size,
 				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
-	rx_queue->page_ptr_mask = page_ring_size - 1;
+	if (!rx_queue->page_ring)
+		rx_queue->page_ptr_mask = 0;
+	else
+		rx_queue->page_ptr_mask = page_ring_size - 1;
 }
 
 void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue)
-- 
2.34.1