This is a note to let you know that I've just added the patch titled net: geneve: check skb is large enough for IPv4/IPv6 header to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-geneve-check-skb-is-large-enough-for-ipv4-ipv6-h.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b6fb52905f7666dbe8382345903df42a5c4e5fc8 Author: Phillip Potter <phil@xxxxxxxxxxxxxxxx> Date: Sun Apr 11 12:28:24 2021 +0100 net: geneve: check skb is large enough for IPv4/IPv6 header [ 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> diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index c7ec3d24eabc..c33a08d65208 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->info.key.tp_dst, sport); @@ -954,6 +957,9 @@ 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);