netfilter: nf_tables: reject constant set with timeout

commit 5f4fc4bd5cddb4770ab120ce44f02695c4505562 upstream.

This set combination is weird: it allows for elements to be
added/deleted, but once bound to the rule it cannot be updated anymore.
Eventually, all elements expire, leading to an empty set which cannot
be updated anymore. Reject this flags combination.

Cc: stable@vger.kernel.org
Fixes: 761da2935d6e ("netfilter: nf_tables: add set timeout API support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 19dae52384ff163c2fcb8addebbc61512b47ce38..f10419ba6e0bd67808dbb5dd7f5595def65dcee2 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4945,6 +4945,9 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
                if ((flags & (NFT_SET_ANONYMOUS | NFT_SET_TIMEOUT | NFT_SET_EVAL)) ==
                             (NFT_SET_ANONYMOUS | NFT_SET_TIMEOUT))
                        return -EOPNOTSUPP;
+               if ((flags & (NFT_SET_CONSTANT | NFT_SET_TIMEOUT)) ==
+                            (NFT_SET_CONSTANT | NFT_SET_TIMEOUT))
+                       return -EOPNOTSUPP;
        }
 
        desc.dtype = 0;