From: Fernando Fernandez Mancera <ffmancera@riseup.net>
Date: Wed, 4 Sep 2019 14:29:07 +0200
Subject: netfilter: nf_tables: fix possible null-pointer dereference in object
 update
Patch-mainline: v5.4-rc1
Git-commit: aa4095a156b56b00ca202d482b40d191ef5c54e8
References: bsc#1176447

Not all objects have an update operation. If the object type doesn't
implement an update operation and the user tries to update it will hit
EOPNOTSUPP.

Fixes: d62d0ba97b58 ("netfilter: nf_tables: Introduce stateful object update operation")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/netfilter/nf_tables_api.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5140,6 +5140,9 @@ static int nf_tables_updobj(const struct
 	struct nft_trans *trans;
 	int err;
 
+	if (!obj->ops->update)
+		return -EOPNOTSUPP;
+
 	trans = nft_trans_alloc(ctx, NFT_MSG_NEWOBJ,
 				sizeof(struct nft_trans_obj));
 	if (!trans)