diff options
| -rw-r--r-- | net/netlink/af_netlink.c | 46 |
1 files changed, 16 insertions, 30 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 8648a9922aab..980fe4ad0016 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1406,7 +1406,7 @@ 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, *frag __maybe_unused = NULL; + struct sk_buff *skb, *data_skb; int err; if (flags&MSG_OOB) @@ -1418,45 +1418,35 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, if (skb == NULL) goto out; + data_skb = skb; + #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. + * If this skb has a frag_list, then here that means that we + * will have to use the frag_list skb's data for compat tasks + * and the regular skb's data for normal (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 we need to send the compat skb, assign it to the + * 'data_skb' variable so that it will be used below for data + * copying. We keep 'skb' for everything else, including + * freeing both later. */ - 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; - } + if (flags & MSG_CMSG_COMPAT) + data_skb = skb_shinfo(skb)->frag_list; } #endif msg->msg_namelen = 0; - copied = skb->len; + copied = data_skb->len; if (len < copied) { msg->msg_flags |= MSG_TRUNC; copied = len; } - skb_reset_transport_header(skb); - err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); + skb_reset_transport_header(data_skb); + err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied); if (msg->msg_name) { struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; @@ -1476,11 +1466,7 @@ 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 + copied = data_skb->len; skb_free_datagram(sk, skb); |