diff options
Diffstat (limited to 'net/netlink')
-rw-r--r-- | net/netlink/af_netlink.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index d46da6c..da3163d 100644 --- 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) |