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 6087e0b41f5540476f97fe1705b8e74f5a568282..0ba2a46a5370fb0140bf445c562650a0176f4a50 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4413,6 +4413,9 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
                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;
        }
 
        dtype = 0;