netfilter: nf_tables: validate NFTA_SET_TABLE parameter

If the NFTA_SET_TABLE parameter is missing and the NLM_F_DUMP flag is
not set, then a NULL pointer dereference is triggered in
nf_tables_set_lookup because ctx.table is NULL.

Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 2011977cd79d..6947e255cdd8 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2641,6 +2641,8 @@ static int nf_tables_getset(struct net *net, struct sock *nlsk,
         /* Only accept unspec with dump */
         if (nfmsg->nfgen_family == NFPROTO_UNSPEC)
                 return -EAFNOSUPPORT;
+        if (!nla[NFTA_SET_TABLE])
+                return -EINVAL;
 
         set = nf_tables_set_lookup(ctx.table, nla[NFTA_SET_NAME]);
         if (IS_ERR(set))