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-rw-r--r--include/linux/netlink.h16
-rw-r--r--net/ipv4/fib_frontend.c2
-rw-r--r--net/netlink/af_netlink.c35
3 files changed, 35 insertions, 18 deletions
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 86fde81ac2e..7a6c396a263 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -85,6 +85,22 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
+static inline struct sk_buff *
+netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
+{
+ struct sk_buff *nskb;
+
+ nskb = skb_clone(skb, gfp_mask);
+ if (!nskb)
+ return NULL;
+
+ /* This is a large skb, set destructor callback to release head */
+ if (is_vmalloc_addr(skb->head))
+ nskb->destructor = skb->destructor;
+
+ return nskb;
+}
+
/*
* skb should fit one page. This choice is good for headerless malloc.
* But we should limit to 8K so that userspace does not have to
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 05a4888dede..b3f627ac4ed 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -961,7 +961,7 @@ static void nl_fib_input(struct sk_buff *skb)
nlmsg_len(nlh) < sizeof(*frn))
return;
- skb = skb_clone(skb, GFP_KERNEL);
+ skb = netlink_skb_clone(skb, GFP_KERNEL);
if (skb == NULL)
return;
nlh = nlmsg_hdr(skb);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 6967fbcca6c..0c61b59175d 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -849,7 +849,10 @@ static void netlink_skb_destructor(struct sk_buff *skb)
}
#endif
if (is_vmalloc_addr(skb->head)) {
- vfree(skb->head);
+ if (!skb->cloned ||
+ !atomic_dec_return(&(skb_shinfo(skb)->dataref)))
+ vfree(skb->head);
+
skb->head = NULL;
}
if (skb->sk != NULL)
@@ -1532,33 +1535,31 @@ struct sock *netlink_getsockbyfilp(struct file *filp)
return sock;
}
-static struct sk_buff *netlink_alloc_large_skb(unsigned int size)
+static struct sk_buff *netlink_alloc_large_skb(unsigned int size,
+ int broadcast)
{
struct sk_buff *skb;
void *data;
- if (size <= NLMSG_GOODSIZE)
+ if (size <= NLMSG_GOODSIZE || broadcast)
return alloc_skb(size, GFP_KERNEL);
- skb = alloc_skb_head(GFP_KERNEL);
- if (skb == NULL)
- return NULL;
+ size = SKB_DATA_ALIGN(size) +
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
data = vmalloc(size);
if (data == NULL)
- goto err;
+ return NULL;
- skb->head = data;
- skb->data = data;
- skb_reset_tail_pointer(skb);
- skb->end = skb->tail + size;
- skb->len = 0;
- skb->destructor = netlink_skb_destructor;
+ skb = build_skb(data, size);
+ if (skb == NULL)
+ vfree(data);
+ else {
+ skb->head_frag = 0;
+ skb->destructor = netlink_skb_destructor;
+ }
return skb;
-err:
- kfree_skb(skb);
- return NULL;
}
/*
@@ -2244,7 +2245,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
if (len > sk->sk_sndbuf - 32)
goto out;
err = -ENOBUFS;
- skb = netlink_alloc_large_skb(len);
+ skb = netlink_alloc_large_skb(len, dst_group);
if (skb == NULL)
goto out;