Messages in this thread | | | Date | Fri, 19 Aug 2022 09:56:21 +0200 | Subject | Re: [PATCH net v2] net: neigh: don't call kfree_skb() under spin_lock_irqsave() | From | "Denis V. Lunev" <> |
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On 19.08.2022 06:47, 'Yang Yingliang' via den wrote: > 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") > Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> > --- > net/core/neighbour.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/net/core/neighbour.c b/net/core/neighbour.c > index 5b669eb80270..d21c7de1ff1a 100644 > --- a/net/core/neighbour.c > +++ b/net/core/neighbour.c > @@ -309,14 +309,17 @@ static int neigh_del_timer(struct neighbour *n) > > 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); > struct net_device *dev = skb->dev; > + > if (net == NULL || net_eq(dev_net(dev), net)) { > struct in_device *in_dev; > > @@ -328,11 +331,16 @@ static void pneigh_queue_purge(struct sk_buff_head *list, struct net *net) > __skb_unlink(skb, list); > > dev_put(dev); > - kfree_skb(skb); > + dev_kfree_skb_irq(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, Reviewed-by: Denis V. Lunev <den@openvz.org>
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