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authorYang Yingliang <yangyingliang@huawei.com>2022-08-22 10:53:46 +0800
committerDavid S. Miller <davem@davemloft.net>2022-08-24 09:49:20 +0100
commitd5485d9dd24e1d04e5509916515260186eb1455c (patch)
tree51de6d241f5d5dd53a5bfa36b5762eff45765f2c /net
parent550e9a4d858ff0bf872522eb4a802d549b45ac96 (diff)
net: neigh: don't call kfree_skb() under spin_lock_irqsave()
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>
Diffstat (limited to 'net')
-rw-r--r--net/core/neighbour.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 5b669eb80270..78cc8fb68814 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;
@@ -326,13 +329,16 @@ static void pneigh_queue_purge(struct sk_buff_head *list, struct net *net)
in_dev->arp_parms->qlen--;
rcu_read_unlock();
__skb_unlink(skb, list);
-
- dev_put(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,