From: Haiyang Zhang <haiyangz@microsoft.com>

Date: Fri, 21 Apr 2023 10:06:58 -0700

Subject: net: mana: Check if netdev/napi_alloc_frag returns single page

Patch-mainline: v6.4-rc1

Git-commit: df18f2da302f169e1a29098c6ca3b474f1b0269e

References: bsc#1210551

netdev/napi_alloc_frag() may fall back to single page which is smaller

than the requested size.

Add error checking to avoid memory overwritten.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>

---

 drivers/net/ethernet/microsoft/mana/mana_en.c |   15 +++++++++++++++

 1 file changed, 15 insertions(+)

--- a/drivers/net/ethernet/microsoft/mana/mana_en.c

+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c

@@ -512,6 +512,14 @@ static int mana_pre_alloc_rxbufs(struct

 			va = netdev_alloc_frag(mpc->rxbpre_alloc_size);

 			if (!va)

 				goto error;

+

+			page = virt_to_head_page(va);

+			/* Check if the frag falls back to single page */

+			if (compound_order(page) <

+			    get_order(mpc->rxbpre_alloc_size)) {

+				put_page(page);

+				goto error;

+			}

 		} else {

 			page = dev_alloc_page();

 			if (!page)

@@ -1457,6 +1465,13 @@ static void *mana_get_rxfrag(struct mana

 		if (!va)

 			return NULL;

+

+		page = virt_to_head_page(va);

+		/* Check if the frag falls back to single page */

+		if (compound_order(page) < get_order(rxq->alloc_size)) {

+			put_page(page);

+			return NULL;

+		}

 	} else {

 		page = dev_alloc_page();

 		if (!page)