From: Alexander Lobakin alobakin@pm.me
[ Upstream commit 55e729889bb07d68ab071660ce3f5e7a7872ebe8 ]
udp{4,6}_lib_lookup_skb() use ip{,v6}_hdr() to get IP header of the packet. While it's probably OK for non-frag0 paths, this helpers will also point to junk on Fast/frag0 GRO when all headers are located in frags. As a result, sk/skb lookup may fail or give wrong results. To support both GRO modes, skb_gro_network_header() might be used. To not modify original functions, add private versions of udp{4,6}_lib_lookup_skb() only to perform correct sk lookups on GRO.
Present since the introduction of "application-level" UDP GRO in 4.7-rc1.
Misc: replace totally unneeded ternaries with plain ifs.
Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket") Suggested-by: Willem de Bruijn willemb@google.com Cc: Eric Dumazet edumazet@google.com Signed-off-by: Alexander Lobakin alobakin@pm.me Acked-by: Willem de Bruijn willemb@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/udp_offload.c | 17 +++++++++++++++-- net/ipv6/udp_offload.c | 17 +++++++++++++++-- 2 files changed, 30 insertions(+), 4 deletions(-)
--- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -500,12 +500,22 @@ out: } EXPORT_SYMBOL(udp_gro_receive);
+static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, + __be16 dport) +{ + const struct iphdr *iph = skb_gro_network_header(skb); + + return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, + iph->daddr, dport, inet_iif(skb), + inet_sdif(skb), &udp_table, NULL); +} + INDIRECT_CALLABLE_SCOPE struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) { struct udphdr *uh = udp_gro_udphdr(skb); + struct sock *sk = NULL; struct sk_buff *pp; - struct sock *sk;
if (unlikely(!uh)) goto flush; @@ -523,7 +533,10 @@ struct sk_buff *udp4_gro_receive(struct skip: NAPI_GRO_CB(skb)->is_ipv6 = 0; rcu_read_lock(); - sk = static_branch_unlikely(&udp_encap_needed_key) ? udp4_lib_lookup_skb(skb, uh->source, uh->dest) : NULL; + + if (static_branch_unlikely(&udp_encap_needed_key)) + sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); + pp = udp_gro_receive(head, skb, uh, sk); rcu_read_unlock(); return pp; --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -111,12 +111,22 @@ out: return segs; }
+static struct sock *udp6_gro_lookup_skb(struct sk_buff *skb, __be16 sport, + __be16 dport) +{ + const struct ipv6hdr *iph = skb_gro_network_header(skb); + + return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, + &iph->daddr, dport, inet6_iif(skb), + inet6_sdif(skb), &udp_table, NULL); +} + INDIRECT_CALLABLE_SCOPE struct sk_buff *udp6_gro_receive(struct list_head *head, struct sk_buff *skb) { struct udphdr *uh = udp_gro_udphdr(skb); + struct sock *sk = NULL; struct sk_buff *pp; - struct sock *sk;
if (unlikely(!uh)) goto flush; @@ -135,7 +145,10 @@ struct sk_buff *udp6_gro_receive(struct skip: NAPI_GRO_CB(skb)->is_ipv6 = 1; rcu_read_lock(); - sk = static_branch_unlikely(&udpv6_encap_needed_key) ? udp6_lib_lookup_skb(skb, uh->source, uh->dest) : NULL; + + if (static_branch_unlikely(&udpv6_encap_needed_key)) + sk = udp6_gro_lookup_skb(skb, uh->source, uh->dest); + pp = udp_gro_receive(head, skb, uh, sk); rcu_read_unlock(); return pp;