From: Martin KaFai Lau <kafai@fb.com>
Date: Fri, 31 May 2019 22:29:13 +0000 (-0700)
Subject: bpf: udp: Avoid calling reuseport's bpf_prog from udp_gro
X-Git-Tag: v5.1.16~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=da6dab6373b223a3f05df6b2236a3ffa81ed7cb8;p=thirdparty%2Fkernel%2Fstable.git

bpf: udp: Avoid calling reuseport's bpf_prog from udp_gro

commit 257a525fe2e49584842c504a92c27097407f778f upstream.

When the commit a6024562ffd7 ("udp: Add GRO functions to UDP socket")
added udp[46]_lib_lookup_skb to the udp_gro code path, it broke
the reuseport_select_sock() assumption that skb->data is pointing
to the transport header.

This patch follows an earlier __udp6_lib_err() fix by
passing a NULL skb to avoid calling the reuseport's bpf_prog.

Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 7b359012e4964..ee999cb5e6705 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -503,7 +503,11 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
 				 __be16 sport, __be16 dport)
 {
-	return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table);
+	const struct iphdr *iph = ip_hdr(skb);
+
+	return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
+				 iph->daddr, dport, inet_iif(skb),
+				 inet_sdif(skb), &udp_table, NULL);
 }
 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb);
 
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index ecb4ae37e3bf1..c5eff697a2f59 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -242,7 +242,7 @@ struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
 
 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
 				 &iph->daddr, dport, inet6_iif(skb),
-				 inet6_sdif(skb), &udp_table, skb);
+				 inet6_sdif(skb), &udp_table, NULL);
 }
 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);