Commit 302a50bc authored by Steffen Klassert's avatar Steffen Klassert

xfrm: Fix potential null pointer dereference in xdst_queue_output

The net_device might be not set on the skb when we try refcounting.
This leads to a null pointer dereference in xdst_queue_output().
It turned out that the refcount to the net_device is not needed
after all. The dst_entry has a refcount to the net_device before
we queue the skb, so it can't go away. Therefore we can remove the
refcount on queueing to fix the null pointer dereference.
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
parent 9c9c9ad5
...@@ -320,10 +320,8 @@ static void xfrm_queue_purge(struct sk_buff_head *list) ...@@ -320,10 +320,8 @@ static void xfrm_queue_purge(struct sk_buff_head *list)
{ {
struct sk_buff *skb; struct sk_buff *skb;
while ((skb = skb_dequeue(list)) != NULL) { while ((skb = skb_dequeue(list)) != NULL)
dev_put(skb->dev);
kfree_skb(skb); kfree_skb(skb);
}
} }
/* Rule must be locked. Release descentant resources, announce /* Rule must be locked. Release descentant resources, announce
...@@ -1758,7 +1756,6 @@ static void xfrm_policy_queue_process(unsigned long arg) ...@@ -1758,7 +1756,6 @@ static void xfrm_policy_queue_process(unsigned long arg)
struct sk_buff *skb; struct sk_buff *skb;
struct sock *sk; struct sock *sk;
struct dst_entry *dst; struct dst_entry *dst;
struct net_device *dev;
struct xfrm_policy *pol = (struct xfrm_policy *)arg; struct xfrm_policy *pol = (struct xfrm_policy *)arg;
struct xfrm_policy_queue *pq = &pol->polq; struct xfrm_policy_queue *pq = &pol->polq;
struct flowi fl; struct flowi fl;
...@@ -1805,7 +1802,6 @@ static void xfrm_policy_queue_process(unsigned long arg) ...@@ -1805,7 +1802,6 @@ static void xfrm_policy_queue_process(unsigned long arg)
dst = xfrm_lookup(xp_net(pol), skb_dst(skb)->path, dst = xfrm_lookup(xp_net(pol), skb_dst(skb)->path,
&fl, skb->sk, 0); &fl, skb->sk, 0);
if (IS_ERR(dst)) { if (IS_ERR(dst)) {
dev_put(skb->dev);
kfree_skb(skb); kfree_skb(skb);
continue; continue;
} }
...@@ -1814,9 +1810,7 @@ static void xfrm_policy_queue_process(unsigned long arg) ...@@ -1814,9 +1810,7 @@ static void xfrm_policy_queue_process(unsigned long arg)
skb_dst_drop(skb); skb_dst_drop(skb);
skb_dst_set(skb, dst); skb_dst_set(skb, dst);
dev = skb->dev;
err = dst_output(skb); err = dst_output(skb);
dev_put(dev);
} }
return; return;
...@@ -1839,7 +1833,6 @@ static int xdst_queue_output(struct sk_buff *skb) ...@@ -1839,7 +1833,6 @@ static int xdst_queue_output(struct sk_buff *skb)
} }
skb_dst_force(skb); skb_dst_force(skb);
dev_hold(skb->dev);
spin_lock_bh(&pq->hold_queue.lock); spin_lock_bh(&pq->hold_queue.lock);
......
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