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authorEric Dumazet <eric.dumazet@gmail.com>2013-06-28 02:37:42 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-28 16:18:35 -0700
commitf4ded0dfedaa8cab85c67fd5db5b9eef9f981c15 (patch)
treec8d2678715d194687e1885dcbeedf8a62b41f2a8
parent3a35ccb6009ad66aa21f821a3c99ca0374b59a28 (diff)
neighbour: fix a race in neigh_destroy()
[ Upstream commit c9ab4d85de222f3390c67aedc9c18a50e767531e ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 34032f27c513..f268c3444e1c 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -237,7 +237,7 @@ 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->output = neigh_blackhole;
if (n->nud_state & NUD_VALID)
n->nud_state = NUD_NOARP;
@@ -291,7 +291,7 @@ static struct neighbour *neigh_alloc(struct neigh_table *tbl)
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;
@@ -712,7 +712,9 @@ void neigh_destroy(struct neighbour *neigh)
hh_cache_put(hh);
}
- skb_queue_purge(&neigh->arp_queue);
+ write_lock_bh(&neigh->lock);
+ __skb_queue_purge(&neigh->arp_queue);
+ write_unlock_bh(&neigh->lock);
dev_put(neigh->dev);
neigh_parms_put(neigh->parms);
@@ -864,7 +866,7 @@ 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);
}
/* Called when a timer expires for a neighbour entry. */
@@ -1188,7 +1190,7 @@ 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);
}
out:
if (update_isrouter) {