From: Yang Yingliang yangyingliang@huawei.com
commit d5485d9dd24e1d04e5509916515260186eb1455c upstream.
It is not allowed to call kfree_skb() from hardware interrupt context or with interrupts being disabled. So add all skb to a tmp list, then free them after spin_unlock_irqrestore() at once.
Fixes: 66ba215cb513 ("neigh: fix possible DoS due to net iface start/stop loop") Suggested-by: Denis V. Lunev den@openvz.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com Reviewed-by: Nikolay Aleksandrov razor@blackwall.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/neighbour.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -281,21 +281,27 @@ static int neigh_del_timer(struct neighb
static void pneigh_queue_purge(struct sk_buff_head *list, struct net *net) { + struct sk_buff_head tmp; unsigned long flags; struct sk_buff *skb;
+ skb_queue_head_init(&tmp); spin_lock_irqsave(&list->lock, flags); skb = skb_peek(list); while (skb != NULL) { struct sk_buff *skb_next = skb_peek_next(skb, list); if (net == NULL || net_eq(dev_net(skb->dev), net)) { __skb_unlink(skb, list); - dev_put(skb->dev); - kfree_skb(skb); + __skb_queue_tail(&tmp, skb); } skb = skb_next; } spin_unlock_irqrestore(&list->lock, flags); + + while ((skb = __skb_dequeue(&tmp))) { + dev_put(skb->dev); + kfree_skb(skb); + } }
static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev,