netfilter: nf_tables: out-of-bound check in chain blob

Add current size of rule expressions to the boundary check.

Fixes: 2c865a8a28a1 ("netfilter: nf_tables: add rule blob layout")
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 3445b8e1f462f73be4a385a9e8ea1c797dfc129f..0519d45ede6b9e009afcd168113e4a791922eb11 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9007,7 +9007,7 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha
                                continue;
                        }
 
-                       if (WARN_ON_ONCE(data + expr->ops->size > data_boundary))
+                       if (WARN_ON_ONCE(data + size + expr->ops->size > data_boundary))
                                return -ENOMEM;
 
                        memcpy(data + size, expr, expr->ops->size);