[PATCH 8/8] netfilter: nf_tables: fix possible null-pointer dereference in object update

[Pablo Neira Ayuso]

From: Fernando Fernandez Mancera <ffmanc...@riseup.net>

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 <ffmanc...@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index cf767bc58e18..013d28899cab 100644
--- 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 nft_ctx *ctx,
        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)
-- 
2.11.0