Messages in this thread Patch in this message | | | From | Yang Yingliang <> | Subject | [PATCH net v2] net: neigh: don't call kfree_skb() under spin_lock_irqsave() | Date | Fri, 19 Aug 2022 12:47:24 +0800 |
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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, -- 2.25.1
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