leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

netfilter: ipt_CLUSTERIP: fix a refcount bug in clusterip_config_find_get()

Browse Source 
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: d73f33b168 ("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>
This commit is contained in:
Cong Wang 2018-02-08 13:53:52 -08:00 committed by Pablo Neira Ayuso
parent 57ebd808a9
commit db93a3632b
1 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
net/ipv4/netfilter/ipt_CLUSTERIP.c
View File

@ -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();