diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2012-04-05 22:17:46 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-04-06 04:21:06 -0400 |
| commit | 4a7e7c2ad540e54c75489a70137bf0ec15d3a127 (patch) | |
| tree | 6e4b141c33e96f807e3d85bfe217bb5a3c8bcf0a | |
| parent | e34fac1c2e9ec531c2d63a5e3aa9a6d0ef36a1d3 (diff) | |
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>
| -rw-r--r-- | net/netlink/af_netlink.c | 24 |
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); |