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From 123bf15c1a15f8dc7b5aceb5186bed37f2e80af5 Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang@huawei.com>
Date: Mon, 22 Aug 2022 10:53:46 +0800
Subject: [PATCH 71/73] net: neigh: don't call kfree_skb() under
spin_lock_irqsave()
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(-)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 19d99d1eff53..fbaa557ed7ec 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -309,21 +309,27 @@ 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);
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,
--
2.37.3
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