| Date | Tue, 02 Oct 2012 00:53:15 +0200 | From | Willy Tarreau <> | Subject | [ 078/180] net: fix a race in sock_queue_err_skb() |
| |
2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <eric.dumazet@gmail.com>
[ Upstream commit 110c43304db6f06490961529536c362d9ac5732f ]
As soon as an skb is queued into socket error 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu> --- net/core/skbuff.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 025f924..72ff527 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2989,6 +2989,8 @@ static void sock_rmem_free(struct sk_buff *skb) */ int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) { + int len = skb->len; + if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= (unsigned)sk->sk_rcvbuf) return -ENOMEM; @@ -3000,7 +3002,7 @@ int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) skb_queue_tail(&sk->sk_error_queue, skb); if (!sock_flag(sk, SOCK_DEAD)) - sk->sk_data_ready(sk, skb->len); + sk->sk_data_ready(sk, len); return 0; } EXPORT_SYMBOL(sock_queue_err_skb); -- 1.7.2.1.45.g54fbc
|