From: Phillip Potter <phil@xxxxxxxxxxxxxxxx> [ Upstream commit 6628ddfec7580882f11fdc5c194a8ea781fdadfa ] 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@xxxxxxxxxx> Reported-by: syzbot+2e406a9ac75bb71d4b7a@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Phillip Potter <phil@xxxxxxxxxxxxxxxx> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/geneve.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index 2e2afc824a6a..ce6fecf421f8 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -839,6 +839,9 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev, __be16 df; 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->info.key.tp_dst, sport); @@ -882,6 +885,9 @@ 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->info.key.tp_dst, sport); -- 2.30.2
