netfilter: nf_tables: skip transaction if no update flags in tables

Skip transaction handling for table updates with no changes in
the flags. This fixes a crash when passing the table flag with all
bits unset.

Reported-by: Ana Rey <anarey@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ab4566cfcbe4..da5dc37a7402 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -407,6 +407,9 @@ static int nf_tables_updtable(struct nft_ctx *ctx)
         if (flags & ~NFT_TABLE_F_DORMANT)
                 return -EINVAL;
 
+        if (flags == ctx->table->flags)
+                return 0;
+
         trans = nft_trans_alloc(ctx, NFT_MSG_NEWTABLE,
                                 sizeof(struct nft_trans_table));
         if (trans == NULL)