netfilter: nf_tables: NULL pointer dereference in nf_tables_updobj()

static analyzer detect null pointer dereference case for 'type'
function __nft_obj_type_get() can return NULL value which require to handle
if type is NULL pointer return -ENOENT.

This is a theoretical issue, since an existing object has a type, but
better add this failsafe check.

Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 974b95dece1db95d18e1ca55cb3526bed801024e..2abf473c8f6729613b96e1d1f4865d0bb8ace759 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7023,6 +7023,9 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info,
                        return -EOPNOTSUPP;
 
                type = __nft_obj_type_get(objtype);
+               if (WARN_ON_ONCE(!type))
+                       return -ENOENT;
+
                nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla);
 
                return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj);