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| author | Cong Wang <xiyou.wangcong@gmail.com> | 2018-02-08 22:53:52 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-02-14 21:05:32 +0100 |
| commit | db93a3632b0f8773a3899e04a3a3e0aa7a26eb46 (patch) | |
| tree | 326e1da2fc4b76761b74712758a4fa84d7aacdce /net | |
| parent | netfilter: add back stackpointer size checks (diff) | |
| download | linux-db93a3632b0f8773a3899e04a3a3e0aa7a26eb46.tar.xz linux-db93a3632b0f8773a3899e04a3a3e0aa7a26eb46.zip | |
netfilter: ipt_CLUSTERIP: fix a refcount bug in clusterip_config_find_get()
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>
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 1ff72b87a066..4b02ab39ebc5 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -154,8 +154,12 @@ clusterip_config_find_get(struct net *net, __be32 clusterip, int entry) #endif if (unlikely(!refcount_inc_not_zero(&c->refcount))) c = NULL; - else if (entry) - refcount_inc(&c->entries); + else if (entry) { + if (unlikely(!refcount_inc_not_zero(&c->entries))) { + clusterip_config_put(c); + c = NULL; + } + } } rcu_read_unlock_bh(); |