Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...

[mv-sheeva.git] / net / netlink / af_netlink.c

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index d46da6cb92e4922b41edf106ab58e88112553bce..d0ff382c40ca96cfe66752379039218714c966a1 100644 (file)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1361,7 +1361,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
        struct netlink_sock *nlk = nlk_sk(sk);
        int noblock = flags&MSG_DONTWAIT;
        size_t copied;
-       struct sk_buff *skb;
+       struct sk_buff *skb, *frag __maybe_unused = NULL;
        int err;
 
        if (flags&MSG_OOB)
@@ -1373,6 +1373,35 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
        if (skb == NULL)
                goto out;
 
+#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
+       if (unlikely(skb_shinfo(skb)->frag_list)) {
+               bool need_compat = !!(flags & MSG_CMSG_COMPAT);
+
+               /*
+                * If this skb has a frag_list, then here that means that
+                * we will have to use the frag_list skb for compat tasks
+                * and the regular skb for non-compat tasks.
+                *
+                * The skb might (and likely will) be cloned, so we can't
+                * just reset frag_list and go on with things -- we need to
+                * keep that. For the compat case that's easy -- simply get
+                * a reference to the compat skb and free the regular one
+                * including the frag. For the non-compat case, we need to
+                * avoid sending the frag to the user -- so assign NULL but
+                * restore it below before freeing the skb.
+                */
+               if (need_compat) {
+                       struct sk_buff *compskb = skb_shinfo(skb)->frag_list;
+                       skb_get(compskb);
+                       kfree_skb(skb);
+                       skb = compskb;
+               } else {
+                       frag = skb_shinfo(skb)->frag_list;
+                       skb_shinfo(skb)->frag_list = NULL;
+               }
+       }
+#endif
+
        msg->msg_namelen = 0;
 
        copied = skb->len;
@@ -1403,6 +1432,11 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
        siocb->scm->creds = *NETLINK_CREDS(skb);
        if (flags & MSG_TRUNC)
                copied = skb->len;
+
+#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
+       skb_shinfo(skb)->frag_list = frag;
+#endif
+
        skb_free_datagram(sk, skb);
 
        if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
@@ -1671,7 +1705,7 @@ errout:
 }
 
 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
-                      struct nlmsghdr *nlh,
+                      const struct nlmsghdr *nlh,
                       int (*dump)(struct sk_buff *skb,
                                   struct netlink_callback *),
                       int (*done)(struct netlink_callback *))