2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Eric Dumazet <[email protected]> [ 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 <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Willy Tarreau <[email protected]> --- net/core/neighbour.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index e696250..fc9feaa 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) { -- 1.7.12.2.21.g234cd45.dirty -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
