net: gro: fix misuse of CB in udp socket lookup

This patch fixes a misuse of IP{6}CB(skb) in GRO, while calling to
`udp6_lib_lookup2` when handling udp tunnels. `udp6_lib_lookup2` fetch the
device from CB. The fix changes it to fetch the device from `skb->dev`.
l3mdev case requires special attention since it has a master and a slave
device.

Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket")
Reported-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/gro.h b/include/net/gro.h
index 75efa6f..88644b3 100644 (file)
--- a/include/net/gro.h
+++ b/include/net/gro.h
@@ -452,6 +452,49 @@ static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb,
                gro_normal_list(napi);
 }
 
+/* This function is the alternative of 'inet_iif' and 'inet_sdif'
+ * functions in case we can not rely on fields of IPCB.
+ *
+ * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
+ * The caller must hold the RCU read lock.
+ */
+static inline void inet_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
+{
+       *iif = inet_iif(skb) ?: skb->dev->ifindex;
+       *sdif = 0;
+
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+       if (netif_is_l3_slave(skb->dev)) {
+               struct net_device *master = netdev_master_upper_dev_get_rcu(skb->dev);
+
+               *sdif = *iif;
+               *iif = master ? master->ifindex : 0;
+       }
+#endif
+}
+
+/* This function is the alternative of 'inet6_iif' and 'inet6_sdif'
+ * functions in case we can not rely on fields of IP6CB.
+ *
+ * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
+ * The caller must hold the RCU read lock.
+ */
+static inline void inet6_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
+{
+       /* using skb->dev->ifindex because skb_dst(skb) is not initialized */
+       *iif = skb->dev->ifindex;
+       *sdif = 0;
+
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+       if (netif_is_l3_slave(skb->dev)) {
+               struct net_device *master = netdev_master_upper_dev_get_rcu(skb->dev);
+
+               *sdif = *iif;
+               *iif = master ? master->ifindex : 0;
+       }
+#endif
+}
+
 extern struct list_head offload_base;
 
 #endif /* _NET_IPV6_GRO_H */

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 42a96b3..abfa860 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -114,6 +114,7 @@
 #include <net/sock_reuseport.h>
 #include <net/addrconf.h>
 #include <net/udp_tunnel.h>
+#include <net/gro.h>
 #if IS_ENABLED(CONFIG_IPV6)
 #include <net/ipv6_stubs.h>
 #endif
@@ -555,10 +556,13 @@ struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
 {
        const struct iphdr *iph = ip_hdr(skb);
        struct net *net = dev_net(skb->dev);
+       int iif, sdif;
+
+       inet_get_iif_sdif(skb, &iif, &sdif);
 
        return __udp4_lib_lookup(net, iph->saddr, sport,
-                                iph->daddr, dport, inet_iif(skb),
-                                inet_sdif(skb), net->ipv4.udp_table, NULL);
+                                iph->daddr, dport, iif,
+                                sdif, net->ipv4.udp_table, NULL);
 }
 
 /* Must be called under rcu_read_lock().

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index f402946..0f46b3c 100644 (file)
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -609,10 +609,13 @@ static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
 {
        const struct iphdr *iph = skb_gro_network_header(skb);
        struct net *net = dev_net(skb->dev);
+       int iif, sdif;
+
+       inet_get_iif_sdif(skb, &iif, &sdif);
 
        return __udp4_lib_lookup(net, iph->saddr, sport,
-                                iph->daddr, dport, inet_iif(skb),
-                                inet_sdif(skb), net->ipv4.udp_table, NULL);
+                                iph->daddr, dport, iif,
+                                sdif, net->ipv4.udp_table, NULL);
 }
 
 INDIRECT_CALLABLE_SCOPE

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index b7c972a..e5da5d1 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -51,6 +51,7 @@
 #include <net/inet6_hashtables.h>
 #include <net/busy_poll.h>
 #include <net/sock_reuseport.h>
+#include <net/gro.h>
 
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
@@ -300,10 +301,13 @@ struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
 {
        const struct ipv6hdr *iph = ipv6_hdr(skb);
        struct net *net = dev_net(skb->dev);
+       int iif, sdif;
+
+       inet6_get_iif_sdif(skb, &iif, &sdif);
 
        return __udp6_lib_lookup(net, &iph->saddr, sport,
-                                &iph->daddr, dport, inet6_iif(skb),
-                                inet6_sdif(skb), net->ipv4.udp_table, NULL);
+                                &iph->daddr, dport, iif,
+                                sdif, net->ipv4.udp_table, NULL);
 }
 
 /* Must be called under rcu_read_lock().

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 09fa7a4..6b95ba2 100644 (file)
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -118,10 +118,13 @@ static struct sock *udp6_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
 {
        const struct ipv6hdr *iph = skb_gro_network_header(skb);
        struct net *net = dev_net(skb->dev);
+       int iif, sdif;
+
+       inet6_get_iif_sdif(skb, &iif, &sdif);
 
        return __udp6_lib_lookup(net, &iph->saddr, sport,
-                                &iph->daddr, dport, inet6_iif(skb),
-                                inet6_sdif(skb), net->ipv4.udp_table, NULL);
+                                &iph->daddr, dport, iif,
+                                sdif, net->ipv4.udp_table, NULL);
 }
 
 INDIRECT_CALLABLE_SCOPE