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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2013-06-28 02:37:42 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-07-01 13:35:32 -0700 |
| commit | c9ab4d85de222f3390c67aedc9c18a50e767531e (patch) | |
| tree | 6bbd193b81267981efecbd296c39e197e15f0ced | |
| parent | 61369d0259a724606f3941a46d2c75155d66cf2c (diff) | |
| download | blackbird-obmc-linux-c9ab4d85de222f3390c67aedc9c18a50e767531e.tar.gz blackbird-obmc-linux-c9ab4d85de222f3390c67aedc9c18a50e767531e.zip | |
neighbour: fix a race in neigh_destroy()
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>
| -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 2569ab2cafbe..b7de821f98df 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -231,7 +231,7 @@ 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) @@ -286,7 +286,7 @@ 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; @@ -708,7 +708,9 @@ void neigh_destroy(struct neighbour *neigh) if (neigh_del_timer(neigh)) pr_warn("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) @@ -858,7 +860,7 @@ 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; } @@ -1210,7 +1212,7 @@ 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: |
