[PATCH net 1/5] netfilter: nf_tables: Add null check for nla_nest_start_noflag() in nft_dump_basechain_hook()

From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org,
	pabeni@redhat.com, edumazet@google.com, fw@strlen.de
Subject: [PATCH net 1/5] netfilter: nf_tables: Add null check for nla_nest_start_noflag() in nft_dump_basechain_hook()
Date: Wed,  7 Jun 2023 00:58:47 +0200	[thread overview]
Message-ID: <20230606225851.67394-2-pablo@netfilter.org> (raw)
In-Reply-To: <20230606225851.67394-1-pablo@netfilter.org>

From: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>

The nla_nest_start_noflag() function may fail and return NULL;
the return value needs to be checked.

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.

Fixes: d54725cd11a5 ("netfilter: nf_tables: support for multiple devices per netdev hook")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index dc5675962de4..3445b8e1f462 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1600,6 +1600,8 @@ static int nft_dump_basechain_hook(struct sk_buff *skb, int family,
 
 	if (nft_base_chain_netdev(family, ops->hooknum)) {
 		nest_devs = nla_nest_start_noflag(skb, NFTA_HOOK_DEVS);
+		if (!nest_devs)
+			goto nla_put_failure;
 
 		if (!hook_list)
 			hook_list = &basechain->hook_list;
-- 
2.30.2

