diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2013-06-28 02:37:42 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-28 16:25:58 -0700 |
| commit | b42e9bf6ff206b1aca6a901fd7c89a8e09a5bda7 (patch) | |
| tree | ce407dde31ab2263cb31588d3edff73d694f9c04 | |
| parent | 0ddce1514e3236adee49a760d2d6339f506b5680 (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.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index ac88107d1bc9..69b7ca35c461 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->arp_queue_len_bytes = 0; n->output = neigh_blackhole; if (n->nud_state & NUD_VALID) @@ -300,7 +300,7 @@ 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; @@ -721,7 +721,9 @@ void neigh_destroy(struct neighbour *neigh) if (neigh_del_timer(neigh)) printk(KERN_WARNING "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) @@ -867,7 +869,7 @@ 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; } @@ -1206,7 +1208,7 @@ 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: |