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authorEric Dumazet <eric.dumazet@gmail.com>2013-06-28 02:37:42 -0700
committerDavid S. Miller <davem@davemloft.net>2013-07-01 13:35:32 -0700
commitc9ab4d85de222f3390c67aedc9c18a50e767531e (patch)
tree6bbd193b81267981efecbd296c39e197e15f0ced
parent61369d0259a724606f3941a46d2c75155d66cf2c (diff)
neighbour: fix a race in neigh_destroy()
There is a race in neighbour code, because neigh_destroy() uses skb_queue_purge(&neigh->arp_queue) without holding neighbour lock, while other parts of the code assume neighbour rwlock is what protects arp_queue Convert all skb_queue_purge() calls to the __skb_queue_purge() variant Use __skb_queue_head_init() instead of skb_queue_head_init() to make clear we do not use arp_queue.lock And hold neigh->lock in neigh_destroy() to close the race. Reported-by: Joe Jin <joe.jin@oracle.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/neighbour.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 2569ab2cafbe..b7de821f98df 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -231,7 +231,7 @@ static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev)
we must kill timers etc. and move
it to safe state.
*/
- skb_queue_purge(&n->arp_queue);
+ __skb_queue_purge(&n->arp_queue);
n->arp_queue_len_bytes = 0;
n->output = neigh_blackhole;
if (n->nud_state & NUD_VALID)
@@ -286,7 +286,7 @@ static struct neighbour *neigh_alloc(struct neigh_table *tbl, struct net_device
if (!n)
goto out_entries;
- skb_queue_head_init(&n->arp_queue);
+ __skb_queue_head_init(&n->arp_queue);
rwlock_init(&n->lock);
seqlock_init(&n->ha_lock);
n->updated = n->used = now;
@@ -708,7 +708,9 @@ void neigh_destroy(struct neighbour *neigh)
if (neigh_del_timer(neigh))
pr_warn("Impossible event\n");
- skb_queue_purge(&neigh->arp_queue);
+ write_lock_bh(&neigh->lock);
+ __skb_queue_purge(&neigh->arp_queue);
+ write_unlock_bh(&neigh->lock);
neigh->arp_queue_len_bytes = 0;
if (dev->netdev_ops->ndo_neigh_destroy)
@@ -858,7 +860,7 @@ static void neigh_invalidate(struct neighbour *neigh)
neigh->ops->error_report(neigh, skb);
write_lock(&neigh->lock);
}
- skb_queue_purge(&neigh->arp_queue);
+ __skb_queue_purge(&neigh->arp_queue);
neigh->arp_queue_len_bytes = 0;
}
@@ -1210,7 +1212,7 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
write_lock_bh(&neigh->lock);
}
- skb_queue_purge(&neigh->arp_queue);
+ __skb_queue_purge(&neigh->arp_queue);
neigh->arp_queue_len_bytes = 0;
}
out: