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authorEric Dumazet <eric.dumazet@gmail.com>2012-04-05 22:17:46 +0000
committerDavid S. Miller <davem@davemloft.net>2012-04-06 04:21:06 -0400
commit4a7e7c2ad540e54c75489a70137bf0ec15d3a127 (patch)
tree6e4b141c33e96f807e3d85bfe217bb5a3c8bcf0a /net
parente34fac1c2e9ec531c2d63a5e3aa9a6d0ef36a1d3 (diff)
downloadlinux-linaro-stable-4a7e7c2ad540e54c75489a70137bf0ec15d3a127.tar.gz
netlink: fix races after skb queueing
As soon as an skb is queued into socket receive_queue, another thread can consume it, so we are not allowed to reference skb anymore, or risk use after free. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/netlink/af_netlink.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 32bb75324e76..faa48f70b7c9 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -829,12 +829,19 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
return 0;
}
-int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
+static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
{
int len = skb->len;
skb_queue_tail(&sk->sk_receive_queue, skb);
sk->sk_data_ready(sk, len);
+ return len;
+}
+
+int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
+{
+ int len = __netlink_sendskb(sk, skb);
+
sock_put(sk);
return len;
}
@@ -957,8 +964,7 @@ static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
!test_bit(0, &nlk->state)) {
skb_set_owner_r(skb, sk);
- skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ __netlink_sendskb(sk, skb);
return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
}
return -1;
@@ -1698,10 +1704,8 @@ static int netlink_dump(struct sock *sk)
if (sk_filter(sk, skb))
kfree_skb(skb);
- else {
- skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
- }
+ else
+ __netlink_sendskb(sk, skb);
return 0;
}
@@ -1715,10 +1719,8 @@ static int netlink_dump(struct sock *sk)
if (sk_filter(sk, skb))
kfree_skb(skb);
- else {
- skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
- }
+ else
+ __netlink_sendskb(sk, skb);
if (cb->done)
cb->done(cb);