From: Phillip Potter phil@philpotter.co.uk
[ 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=abe95dc3e3e9667fc23b8d81f29ecad95c6f106...
Suggested-by: Eric Dumazet edumazet@google.com Reported-by: syzbot+2e406a9ac75bb71d4b7a@syzkaller.appspotmail.com Signed-off-by: Phillip Potter phil@philpotter.co.uk Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/geneve.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index f35b0b83fe85..040edc6fc560 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); @@ -985,6 +988,9 @@ 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);