udplite: fix NULL pointer dereference

The commit 850cbaddb52d ("udp: use it's own memory accounting schema")
assumes that the socket proto has memory accounting enabled,
but this is not the case for UDPLITE.
Fix it enabling memory accounting for UDPLITE and performing
fwd allocated memory reclaiming on socket shutdown.
UDP and UDPLITE share now the same memory accounting limits.
Also drop the backlog receive operation, since is no more needed.

Fixes: 850cbaddb52d ("udp: use it's own memory accounting schema")
Reported-by: Andrei Vagin <avagin@gmail.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 8 insertions, 3 deletions

diff --git a/include/net/udp.h b/include/net/udp.h
index e6e4e19be387..1661791e8ca1 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -246,6 +246,7 @@ static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb,
 }
 
 /* net/ipv4/udp.c */
+void udp_destruct_sock(struct sock *sk);
 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len);
 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb);
 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb);
diff --git a/include/net/udplite.h b/include/net/udplite.h
index 80761938b9a7..36097d388219 100644
--- a/include/net/udplite.h
+++ b/include/net/udplite.h
@@ -27,6 +27,7 @@ static __inline__ int udplite_getfrag(void *from, char *to, int  offset,
 static inline int udplite_sk_init(struct sock *sk)
 {
         udp_sk(sk)->pcflag = UDPLITE_BIT;
+        sk->sk_destruct = udp_destruct_sock;
         return 0;
 }
 
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c827e4ea509e..9ae7c63a8b13 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1253,7 +1253,7 @@ drop:
 }
 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
 
-static void udp_destruct_sock(struct sock *sk)
+void udp_destruct_sock(struct sock *sk)
 {
         /* reclaim completely the forward allocated memory */
         unsigned int total = 0;
@@ -1267,6 +1267,7 @@ static void udp_destruct_sock(struct sock *sk)
 
         inet_sock_destruct(sk);
 }
+EXPORT_SYMBOL_GPL(udp_destruct_sock);
 
 int udp_init_sock(struct sock *sk)
 {
diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c
index af817158d830..59f10fe9782e 100644
--- a/net/ipv4/udplite.c
+++ b/net/ipv4/udplite.c
@@ -50,10 +50,11 @@ struct proto 	udplite_prot = {
         .sendmsg           = udp_sendmsg,
         .recvmsg           = udp_recvmsg,
         .sendpage          = udp_sendpage,
-        .backlog_rcv       = udp_queue_rcv_skb,
         .hash              = udp_lib_hash,
         .unhash            = udp_lib_unhash,
         .get_port          = udp_v4_get_port,
+        .memory_allocated  = &udp_memory_allocated,
+        .sysctl_mem        = sysctl_udp_mem,
         .obj_size          = sizeof(struct udp_sock),
         .h.udp_table       = &udplite_table,
 #ifdef CONFIG_COMPAT
diff --git a/net/ipv6/udplite.c b/net/ipv6/udplite.c
index 47d0d2b87106..2784cc363f2b 100644
--- a/net/ipv6/udplite.c
+++ b/net/ipv6/udplite.c
@@ -45,10 +45,11 @@ struct proto udplitev6_prot = {
         .getsockopt        = udpv6_getsockopt,
         .sendmsg           = udpv6_sendmsg,
         .recvmsg           = udpv6_recvmsg,
-        .backlog_rcv       = udpv6_queue_rcv_skb,
         .hash              = udp_lib_hash,
         .unhash            = udp_lib_unhash,
         .get_port          = udp_v6_get_port,
+        .memory_allocated  = &udp_memory_allocated,
+        .sysctl_mem        = sysctl_udp_mem,
         .obj_size          = sizeof(struct udp6_sock),
         .h.udp_table       = &udplite_table,
 #ifdef CONFIG_COMPAT