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-rw-r--r--net/netlink/af_netlink.c63
-rw-r--r--net/netlink/af_netlink.h10
2 files changed, 59 insertions, 14 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7f86d3b55060..8f060d7f9a0e 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -125,6 +125,24 @@ static inline u32 netlink_group_mask(u32 group)
return group ? 1 << (group - 1) : 0;
}
+static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
+ gfp_t gfp_mask)
+{
+ unsigned int len = skb_end_offset(skb);
+ struct sk_buff *new;
+
+ new = alloc_skb(len, gfp_mask);
+ if (new == NULL)
+ return NULL;
+
+ NETLINK_CB(new).portid = NETLINK_CB(skb).portid;
+ NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group;
+ NETLINK_CB(new).creds = NETLINK_CB(skb).creds;
+
+ memcpy(skb_put(new, len), skb->data, len);
+ return new;
+}
+
int netlink_add_tap(struct netlink_tap *nt)
{
if (unlikely(nt->dev->type != ARPHRD_NETLINK))
@@ -206,7 +224,11 @@ static int __netlink_deliver_tap_skb(struct sk_buff *skb,
int ret = -ENOMEM;
dev_hold(dev);
- nskb = skb_clone(skb, GFP_ATOMIC);
+
+ if (netlink_skb_is_mmaped(skb) || is_vmalloc_addr(skb->head))
+ nskb = netlink_to_full_skb(skb, GFP_ATOMIC);
+ else
+ nskb = skb_clone(skb, GFP_ATOMIC);
if (nskb) {
nskb->dev = dev;
nskb->protocol = htons((u16) sk->sk_protocol);
@@ -279,11 +301,6 @@ static void netlink_rcv_wake(struct sock *sk)
}
#ifdef CONFIG_NETLINK_MMAP
-static bool netlink_skb_is_mmaped(const struct sk_buff *skb)
-{
- return NETLINK_CB(skb).flags & NETLINK_SKB_MMAPED;
-}
-
static bool netlink_rx_is_mmaped(struct sock *sk)
{
return nlk_sk(sk)->rx_ring.pg_vec != NULL;
@@ -846,7 +863,6 @@ static void netlink_ring_set_copied(struct sock *sk, struct sk_buff *skb)
}
#else /* CONFIG_NETLINK_MMAP */
-#define netlink_skb_is_mmaped(skb) false
#define netlink_rx_is_mmaped(sk) false
#define netlink_tx_is_mmaped(sk) false
#define netlink_mmap sock_no_mmap
@@ -1094,8 +1110,8 @@ static int netlink_insert(struct sock *sk, u32 portid)
lock_sock(sk);
- err = -EBUSY;
- if (nlk_sk(sk)->portid)
+ err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY;
+ if (nlk_sk(sk)->bound)
goto err;
err = -ENOMEM;
@@ -1115,10 +1131,14 @@ static int netlink_insert(struct sock *sk, u32 portid)
err = -EOVERFLOW;
if (err == -EEXIST)
err = -EADDRINUSE;
- nlk_sk(sk)->portid = 0;
sock_put(sk);
+ goto err;
}
+ /* We need to ensure that the socket is hashed and visible. */
+ smp_wmb();
+ nlk_sk(sk)->bound = portid;
+
err:
release_sock(sk);
return err;
@@ -1503,6 +1523,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
int err;
long unsigned int groups = nladdr->nl_groups;
+ bool bound;
if (addr_len < sizeof(struct sockaddr_nl))
return -EINVAL;
@@ -1519,9 +1540,14 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
return err;
}
- if (nlk->portid)
+ bound = nlk->bound;
+ if (bound) {
+ /* Ensure nlk->portid is up-to-date. */
+ smp_rmb();
+
if (nladdr->nl_pid != nlk->portid)
return -EINVAL;
+ }
if (nlk->netlink_bind && groups) {
int group;
@@ -1537,7 +1563,10 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
}
}
- if (!nlk->portid) {
+ /* No need for barriers here as we return to user-space without
+ * using any of the bound attributes.
+ */
+ if (!bound) {
err = nladdr->nl_pid ?
netlink_insert(sk, nladdr->nl_pid) :
netlink_autobind(sock);
@@ -1585,7 +1614,10 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
!netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
return -EPERM;
- if (!nlk->portid)
+ /* No need for barriers here as we return to user-space without
+ * using any of the bound attributes.
+ */
+ if (!nlk->bound)
err = netlink_autobind(sock);
if (err == 0) {
@@ -2426,10 +2458,13 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
dst_group = nlk->dst_group;
}
- if (!nlk->portid) {
+ if (!nlk->bound) {
err = netlink_autobind(sock);
if (err)
goto out;
+ } else {
+ /* Ensure nlk is hashed and visible. */
+ smp_rmb();
}
/* It's a really convoluted way for userland to ask for mmaped
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
index 89008405d6b4..14437d9b1965 100644
--- a/net/netlink/af_netlink.h
+++ b/net/netlink/af_netlink.h
@@ -35,6 +35,7 @@ struct netlink_sock {
unsigned long state;
size_t max_recvmsg_len;
wait_queue_head_t wait;
+ bool bound;
bool cb_running;
struct netlink_callback cb;
struct mutex *cb_mutex;
@@ -59,6 +60,15 @@ static inline struct netlink_sock *nlk_sk(struct sock *sk)
return container_of(sk, struct netlink_sock, sk);
}
+static inline bool netlink_skb_is_mmaped(const struct sk_buff *skb)
+{
+#ifdef CONFIG_NETLINK_MMAP
+ return NETLINK_CB(skb).flags & NETLINK_SKB_MMAPED;
+#else
+ return false;
+#endif /* CONFIG_NETLINK_MMAP */
+}
+
struct netlink_table {
struct rhashtable hash;
struct hlist_head mc_list;