diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2013-06-28 02:37:42 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2014-05-19 07:53:44 +0200 |
| commit | af6739a5fe47e23aef27d8057db0edbccb13da52 (patch) | |
| tree | 66ae05c888285c7d3bb894c14df32564ab6430e7 /net | |
| parent | 6597b256646d4ff022bedd364b59fa3de0c05acc (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: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'net')
| -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 e69625084481..fc9feaa0c5c3 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -222,7 +222,7 @@ 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; @@ -276,7 +276,7 @@ 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); n->updated = n->used = now; n->nud_state = NUD_NONE; @@ -646,7 +646,9 @@ void neigh_destroy(struct neighbour *neigh) kfree(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); @@ -789,7 +791,7 @@ 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. */ @@ -1105,7 +1107,7 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, n1->output(skb); write_lock_bh(&neigh->lock); } - skb_queue_purge(&neigh->arp_queue); + __skb_queue_purge(&neigh->arp_queue); } out: if (update_isrouter) { |