diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2013-06-28 02:37:42 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-08-02 22:14:46 +0200 |
| commit | cbdcfcd320e5847c8edde45848562aebb1f01f90 (patch) | |
| tree | 8c16c83723b9e3a18e79d87ac3eb7a7060a58c10 /net | |
| parent | 694c73ea108919b72b689a20c218c4249f0fbffb (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: Ben Hutchings <ben@decadent.org.uk>
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 5b9709f18a64..0ea3fd3195b8 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; @@ -701,7 +701,9 @@ 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); dev_put(neigh->dev); neigh_parms_put(neigh->parms); @@ -843,7 +845,7 @@ 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); } static void neigh_probe(struct neighbour *neigh) @@ -1176,7 +1178,7 @@ 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) { |