netdev - [PATCH 18/26] netfilter: nft_ct: fix null pointer in ct expectations support

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Date:   Tue, 25 Jun 2019 02:12:25 +0200
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     netfilter-devel@...r.kernel.org
Cc:     davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 18/26] netfilter: nft_ct: fix null pointer in ct expectations support

From: Stéphane Veyret <sveyret@...il.com>

nf_ct_helper_ext_add may return null, which must then be checked.

Fixes: 857b46027d6f ("netfilter: nft_ct: add ct expectations support")
Reported-by: Colin Ian King <colin.king@...onical.com>
Signed-off-by: Stéphane Veyret <sveyret@...il.com>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nft_ct.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 06b52c894573..77dab1bdb3ca 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -1232,6 +1232,10 @@ static void nft_ct_expect_obj_eval(struct nft_object *obj,
 	help = nfct_help(ct);
 	if (!help)
 		help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
+	if (!help) {
+		regs->verdict.code = NF_DROP;
+		return;
+	}
 
 	if (help->expecting[NF_CT_EXPECT_CLASS_DEFAULT] >= priv->size) {
 		regs->verdict.code = NFT_BREAK;
-- 
2.11.0