current/SOURCES/net-lantiq_xrx200-confirm-skb-is-allocated-before-us.patch

From a2f44019fd08b7d03d3f9f544d460d9d48f97816 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Wed, 24 Aug 2022 23:54:06 +0200
Subject: net: lantiq_xrx200: confirm skb is allocated before using

From: Aleksander Jan Bajkowski <olek2@wp.pl>

[ Upstream commit c8b043702dc0894c07721c5b019096cebc8c798f ]

xrx200_hw_receive() assumes build_skb() always works and goes straight
to skb_reserve(). However, build_skb() can fail under memory pressure.

Add a check in case build_skb() failed to allocate and return NULL.

Fixes: e015593573b3 ("net: lantiq_xrx200: convert to build_skb")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/lantiq_xrx200.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
index 5edb68a8aab1e..89314b645c822 100644
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -239,6 +239,12 @@ static int xrx200_hw_receive(struct xrx200_chan *ch)
        }
 
        skb = build_skb(buf, priv->rx_skb_size);
+       if (!skb) {
+               skb_free_frag(buf);
+               net_dev->stats.rx_dropped++;
+               return -ENOMEM;
+       }
+
        skb_reserve(skb, NET_SKB_PAD);
        skb_put(skb, len);
 
-- 
2.35.1

1	From a2f44019fd08b7d03d3f9f544d460d9d48f97816 Mon Sep 17 00:00:00 2001
2	From: Sasha Levin <sashal@kernel.org>
3	Date: Wed, 24 Aug 2022 23:54:06 +0200
4	Subject: net: lantiq_xrx200: confirm skb is allocated before using
5
6	From: Aleksander Jan Bajkowski <olek2@wp.pl>
7
8	[ Upstream commit c8b043702dc0894c07721c5b019096cebc8c798f ]
9
10	xrx200_hw_receive() assumes build_skb() always works and goes straight
11	to skb_reserve(). However, build_skb() can fail under memory pressure.
12
13	Add a check in case build_skb() failed to allocate and return NULL.
14
15	Fixes: e015593573b3 ("net: lantiq_xrx200: convert to build_skb")
16	Reported-by: Eric Dumazet <edumazet@google.com>
17	Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
18	Signed-off-by: Jakub Kicinski <kuba@kernel.org>
19	Signed-off-by: Sasha Levin <sashal@kernel.org>
20	---
21	drivers/net/ethernet/lantiq_xrx200.c \| 6 ++++++
22	1 file changed, 6 insertions(+)
23
24	diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
25	index 5edb68a8aab1e..89314b645c822 100644
26	--- a/drivers/net/ethernet/lantiq_xrx200.c
27	+++ b/drivers/net/ethernet/lantiq_xrx200.c
28	@@ -239,6 +239,12 @@ static int xrx200_hw_receive(struct xrx200_chan *ch)
29	}
30
31	skb = build_skb(buf, priv->rx_skb_size);
32	+ if (!skb) {
33	+ skb_free_frag(buf);
34	+ net_dev->stats.rx_dropped++;
35	+ return -ENOMEM;
36	+ }
37	+
38	skb_reserve(skb, NET_SKB_PAD);
39	skb_put(skb, len);
40
41	--
42	2.35.1
43