Subject: [PATCH][next] net: mana: Use struct_size() in kzalloc()

From: "Gustavo A. R. Silva" <[email-masked]>
Date: Thu, 13 May 2021 17:49:14 -0500

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows
that, in the worst scenario, could lead to heap overflows.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <[email-masked]>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 04d067243457..46aee2c49f1b 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1387,8 +1387,7 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
 
 	gc = gd->gdma_context;
 
-	rxq = kzalloc(sizeof(*rxq) +
-		      RX_BUFFERS_PER_QUEUE * sizeof(struct mana_recv_buf_oob),
+	rxq = kzalloc(struct_size(rxq, rx_oobs, RX_BUFFERS_PER_QUEUE),
 		      GFP_KERNEL);
 	if (!rxq)
 		return NULL;
-- 
2.27.0