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| author | Cong Wang <xiyou.wangcong@gmail.com> | 2018-02-08 13:53:52 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-06-16 22:22:14 +0100 |
| commit | 7423c3f4f7ccbb321010d3e3c00c51a3e4db50e6 (patch) | |
| tree | c56259561089816bcf7ab24b2199de15b37dd013 /net | |
| parent | aed15b3930175cfebf45fa6e1734606f6ea337a1 (diff) | |
| download | linux-stable-7423c3f4f7ccbb321010d3e3c00c51a3e4db50e6.tar.gz linux-stable-7423c3f4f7ccbb321010d3e3c00c51a3e4db50e6.tar.bz2 linux-stable-7423c3f4f7ccbb321010d3e3c00c51a3e4db50e6.zip | |
netfilter: ipt_CLUSTERIP: fix a refcount bug in clusterip_config_find_get()
commit db93a3632b0f8773a3899e04a3a3e0aa7a26eb46 upstream.
In clusterip_config_find_get() we hold RCU read lock so it could
run concurrently with clusterip_config_entry_put(), as a result,
the refcnt could go back to 1 from 0, which leads to a double
list_del()... Just replace refcount_inc() with
refcount_inc_not_zero(), as for c->refcount.
Fixes: d73f33b16883 ("netfilter: CLUSTERIP: RCU conversion")
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.16: s/refcount/atomic/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/netfilter/ipt_CLUSTERIP.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index ccc3581e98ae..36abfce2c2d9 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -147,8 +147,12 @@ clusterip_config_find_get(struct net *net, __be32 clusterip, int entry) if (c) { if (unlikely(!atomic_inc_not_zero(&c->refcount))) c = NULL; - else if (entry) - atomic_inc(&c->entries); + else if (entry) { + if (unlikely(!atomic_inc_not_zero(&c->entries))) { + clusterip_config_put(c); + c = NULL; + } + } } rcu_read_unlock_bh(); |