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)