From: Phillip Potter <phil@philpotter.co.uk>
To: davem@davemloft.net
Cc: kuba@kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, edumazet@google.com
Subject: [PATCH] net: geneve: check skb is large enough for IPv4/IPv6 header
Date: Sun, 11 Apr 2021 12:28:24 +0100 [thread overview]
Message-ID: <20210411112824.1149-1-phil@philpotter.co.uk> (raw)
Check within geneve_xmit_skb/geneve6_xmit_skb that sk_buff structure
is large enough to include IPv4 or IPv6 header, and reject if not. The
geneve_xmit_skb portion and overall idea was contributed by Eric Dumazet.
Fixes a KMSAN-found uninit-value bug reported by syzbot at:
https://syzkaller.appspot.com/bug?id=abe95dc3e3e9667fc23b8d81f29ecad95c6f106f
Suggested-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+2e406a9ac75bb71d4b7a@syzkaller.appspotmail.com
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
---
drivers/net/geneve.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 5523f069b9a5..adfceb60f7f8 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -891,6 +891,9 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
__be16 sport;
int err;
+ if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
+ return -EINVAL;
+
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info,
geneve->cfg.info.key.tp_dst, sport);
@@ -977,6 +980,9 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
__be16 sport;
int err;
+ if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
+ return -EINVAL;
+
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info,
geneve->cfg.info.key.tp_dst, sport);
--
2.30.2
next reply other threads:[~2021-04-11 11:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-11 11:28 Phillip Potter [this message]
2021-04-11 15:21 ` [PATCH] net: geneve: check skb is large enough for IPv4/IPv6 header Eric Dumazet
2021-04-12 0:00 ` patchwork-bot+netdevbpf
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